Tropical Storm Lane

Tropical Depression Lane Track 0500 Hours August 28 2018
Tropical Depression Lane Track 0500 Hours August 28 2018

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Tue Aug 28 2018

Overnight GOES-15 fog product imagery along with a few VIIRS images and a Monday evening SCATSAT pass show that the exposed low level circulation center (LLCC) of Lane (see Tuesday video below) has started tracking to the west-northwest, and has become increasingly elongated and indistinct during the night. However, for the third night in a row, despite very strong vertical wind shear estimated at 57 kt by CIMSS, Lane managed to produce a substantial and persistent burst of deep convection just to the northeast of the LLCC, which kept the system classifiable for this cycle. Subjective Dvorak current intensity estimates came in at 1.5/25 kt from HFO and SAB, and 2.0/30 kt from JTWC, and the latest CIMSS ADT has increased to 1.9/29 kt in response to the deep convection NE of the center. The overnight ASCAT pass sampled only the eastern part of Lane’s circulation, but did find a small area of 30 kt winds there. We have therefore maintained Lane as a 30 kt tropical depression for this advisory.Tropical Depression Lane Distances 0500 Hours August 28 2018

With the anticipated turn toward the northwest now apparently underway, the initial motion for this advisory is set at 290/9 kt. Lane is now beginning to feel the influence of a strong low aloft which water vapor imagery shows centered near 22N 172W. Model guidance continues to show Lane being picked up by a developing low-level trough induced by the upper trough, with the depression expected to turn NW then NNW later today. The new forecast track is very similar to the previous track, and remains on the left side of the guidance envelope in best agreement with the ECMWF.

Very strong shear is forecast to continue along the forecast track of Lane during the next couple of days. The new intensity forecast anticipates that Lane will become a remnant low later today as the LLCC continues to become less organized, and the current deep convection will likely wane as it has during the past couple of daytime periods. The remnant low will then be absorbed within 36 hours into a larger extratropical low forecast to develop farther to the north.

FORECAST POSITIONS AND MAX WINDS
 
INIT  28/1500Z 18.8N 168.5W   30 KT  35 MPH
 12H  29/0000Z 20.0N 169.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  29/1200Z 21.8N 169.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  30/0000Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Mon Aug 27 2018

The last visible Himawari images of the evening along with more recent GOES-15 fog product images continue to depict the exposed low level circulation center (LLCC) of Lane tracking westward. Infrared imagery shows only small, scattered and short-lived puffs of deep convection in the northern semicircle. These are currently located from 50 nm NW to over 100 nm NE and E of the center. Subjective Dvorak current intensity estimates came in at 2.0/30 kt from HFO and JTWC, and 1.5/25 kt from SAB, while final T-numbers were 1.0 to 1.5 or 25 kt across the board. The latest CIMSS ADT is also 1.5/25 kt. We have conservatively maintained Lane as a 30 kt tropical depression for this advisory, which may be generous.

Initial motion for this advisory is set at 270/6 kt. A strong lower/mid level ridge to the north of Lane has steered the cyclone generally toward the WSW during the past couple of days. This will be changing soon, as Lane continues to approach a strong low aloft which water vapor imagery shows centered near 23N 172W. Model guidance shows Lane being picked up by a developing low-level trough induced by the upper trough, with the depression expected to turn NW then NNW during the next 36 hours. The new forecast track is similar to the previous track, and is on the left side of the guidance envelope in best agreement with the ECMWF.Tropical Depression Lane Distances 2300 Hours August 27 2018

UW-CIMSS diagnoses almost 60 kt of vertical wind shear over Lane, as confirmed by satellite animations which show the tops of any deep convection that develops near the LLCC being quickly ripped away to the northeast. Very strong shear is forecast to continue along the forecast track of Lane during the next couple of days. The intensity forecast anticipates that Lane will continue to weaken, with the remnant low becoming absorbed within 48 hours into a larger extratropical low forecast to develop farther to the north. Unless Lane regains significant deep convection near the center soon, it will likely be designated as a post-tropical remnant low on Tuesday morning.

FORECAST POSITIONS AND MAX WINDS
 
INIT  28/0900Z 18.4N 167.4W   30 KT  35 MPH
 12H  28/1800Z 19.0N 168.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  29/0600Z 20.3N 168.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  29/1800Z 23.0N 169.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  30/0600Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Sun Aug 26 2018

Lane’s  low-level circulation center has been exposed for the better part of the past 24 hours, barring a period this afternoon when bursting convection briefly moved over the center. These thunderstorms were quickly sheared away to the east as Lane remains embedded in an environment characterized by 40-50 kt of vertical wind shear. Subjective Dvorak intensity estimates were 1.5/25 kt from HFO/SAB/GTW, but Lane’s appearance hasn’t changed much since a morning ASCAT pass indicated 30 kt in the northern semicircle. As such, the initial intensity will remain 30 kt for this advisory.

The initial motion for this advisory is 270/8 kt, with Lane being driven westward by a surface high to the distant NE. This motion will continue in the short-term, with the strong shear likely causing Lane to devolve into a post-tropical remnant low on Monday. A brief slowing in forward speed is expected late Monday and Tuesday as the remnant low reaches the southwestern edge of the high and begins to interact with a mid-level low to its west. Although confidence is reduced, this interaction is expected to lead to the development of an extratropical low later Tuesday into Wednesday. This low could bring gale force winds to portions of the Papahanaumokuakea Marine National Monument as it tracks northwest. The updated track and intensity forecast is close to the previous forecast, and represents a blend of regional and global model guidance.Tropical Depression Lane 2300 Hours August 26 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  27/0900Z 18.9N 164.7W   30 KT  35 MPH  (WSW of Puʻuwai, Hawaii)
 12H  27/1800Z 18.9N 165.8W   30 KT  35 MPH  (WSW of Puʻuwai, Hawaii)
 24H  28/0600Z 19.2N 166.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  28/1800Z 20.2N 167.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  29/0600Z 22.0N 168.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  30/0600Z 26.8N 171.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
 96H  31/0600Z 31.0N 175.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  01/0600Z 35.5N 178.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Sun Aug 26 2018

The low-level circulation center of Lane remains exposed with bursts of deep convection continuing to pulse in the northeast quadrant. The once powerful cyclone is in the process of becoming a post-tropical remnant low, as it remains embedded in a hostile environment, with vertical wind shear of around 40 knots impacting the system. The initial intensity for this advisory remains at 30 kt based on the latest Dvorak intensity estimates. Based on an overnight ASCAT pass, these winds are mainly in the northern semicircle of the circulation.

The initial motion for this advisory is 270/9 kt. A surface high to the distant northeast will keep Lane moving generally toward the west into Monday as it devolves into a post-tropical remnant low later today or tonight. Once Lane becomes post-tropical, redevelopment into a tropical cyclone is highly unlikely. A brief slowing in forward speed is expected Monday night as the remnant low reaches the southwestern edge of the high and begins to interact with a developing mid-level low to its west. Assuming Lane survives as a coherent feature until then, this interaction is expected to lead to the development of an extratropical low by Tuesday or Wednesday. This low could bring gale force winds to portions of the Papahanaumokuakea Marine National Monument as it tracks north and northwest around the middle of the week. The latest official forecast track is close to the TVCE consensus while the intensity forecast is supported by global model guidance.Tropical Depression Lane Distances 1100 Hours August 26 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  26/2100Z 19.1N 163.2W   30 KT  35 MPH -Tropical Storm (W Hilo, Hawaii)
 12H  27/0600Z 18.9N 164.7W   30 KT  35 MPH -Tropical Storm (W Hilo, Hawaii)
 24H  27/1800Z 19.0N 166.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  28/0600Z 19.4N 167.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  28/1800Z 20.4N 167.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  29/1800Z 25.0N 169.8W   35 KT  40 MPH...POST-TROP/EXTRATROP
 96H  30/1800Z 30.6N 174.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  31/1800Z 34.0N 179.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Sun Aug 26 2018

Although a few thunderstorms have recently developed in Lane’s  northern semicircle, the low-level circulation remains exposed. The once powerful cyclone is in the process of becoming a post-tropical remnant low, as it remains embedded in a hostile environment characterized by 40-50 kt of vertical wind shear. The initial intensity for this advisory has been lowered to 30 kt based on decreasing Dvorak intensity estimates that are near 2.0/30 kt, and an 0821Z ASCAT pass that detected winds of 30 kt, mainly in the northern semicircle.

The initial motion for this advisory is 260/9 kt. A surface high to the distant northeast will keep Lane moving generally toward the west into Monday as it devolves into a post-tropical remnant low, probably by later today or tonight. Once Lane becomes post-tropical, redevelopment into a tropical cyclone is highly unlikely. A brief slowing in forward speed is expected Monday night as the remnant low reaches the southwestern edge of the high and begins to interact with a developing mid-level low to its west. Assuming Lane survives as a coherent feature until then, this interaction is expected to lead to the development of an extratropical low by Tuesday/Wednesday. This low could bring gale force winds to portions of the Papahanaumokuakea Marine National Monument as it tracks north and northwest around the middle of the week. The latest official forecast track is close to the TVCE consensus while the intensity forecast is supported by global model guidance.Tropical Storm Lane Distances 0500 Hours August 26 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  26/1500Z 19.1N 162.2W   30 KT  35 MPH (WSW of Puʻuwai, Hawaii)
 12H  27/0000Z 19.1N 163.2W   30 KT  35 MPH (WSW of Puʻuwai, Hawaii)
 24H  27/1200Z 19.1N 164.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  28/0000Z 19.5N 166.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  28/1200Z 20.2N 167.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  29/1200Z 24.5N 169.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
 96H  30/1200Z 29.5N 173.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  31/1200Z 34.0N 177.5W   40 KT  45 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Sat Aug 25 2018

Bursts of deep convection continue to pulse near the circulation center of Lane . Lightning has also been persistent near the core of this deep convection. Visible satellite imagery shows the low level circulation center is partially exposed on the southwest side of the deepest convection. Based on the latest Dvorak fixes and the latest satellite representation of Lane, we have lowered the initial intensity to 45 knots. Wind radii were decreased based on an overnight ASCAT pass.

Strong westerly shear of 30 to 40 kt continues to impact lane. Gradual weakening is forecast over the next couple of days due to this strong shear persisting. This follows closely with ICON and SHIPS guidance. Lane is forecast to weaken to a depression in about 36 hours and to a remnant low in about 72 hours. Assuming this low survives, it may eventually become an extratropical gale low in the vicinity of the Northwestern Hawaiian Islands around days 4 and 5. The latest motion for this advisory is 280/6 knots. Early morning visible imagery combined with an AMSR pass at 1205Z confirmed that Lane has made the long awaited turn toward the west. The current track forecast has been shifted to the left through 48 hours, with little change from days 3 through 5.This forecast closely follows the HWRF, and lies close to the consensus models. There are only subtle changes in the track forecast compared with the previous forecast from days 2 through 5.

Based on the confirmation on the turn to the west as well as the latest forecast track, all watches and warnings for the main Hawaiian Islands have been discontinued.Tropical Storm Lane Distances 1100 Hours August 25 2018

KEY MESSAGES:

1. Effects from tropical storms can and do extend well from the center. Lingering moisture associated with Lane will continue to bring persistent flooding rainfall across parts of the state. Locally gusty winds will continue to be accelerated over higher terrain, through gaps, and where winds blow downslope.

FORECAST POSITIONS AND MAX WINDS
  
INIT  25/2100Z 19.7N 159.4W   45 KT  50 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 12H  26/0600Z 19.7N 160.4W   40 KT  45 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 24H  26/1800Z 19.5N 161.8W   35 KT  40 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 36H  27/0600Z 19.4N 163.6W   30 KT  35 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 48H  27/1800Z 19.7N 165.3W   30 KT  35 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 72H  28/1800Z 21.6N 167.4W   30 KT  35 MPH - Tropical Storm (WSW of Puʻuwai, Hawaii)
 96H  29/1800Z 25.5N 169.4W   35 KT  40 MPH...POST-TROPICAL
120H  30/1800Z 30.4N 174.6W   35 KT  40 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Sat Aug 25 2018

DISCUSSION AND OUTLOOK

At 200 AM HST (1200 UTC), the center of Tropical Storm Lane was located near latitude 19.5 North, longitude 158.4 West. Lane is moving toward the north-northwest near 3 mph (6 km/h), and this general motion is expected to continue through this morning. This will likely be followed by a turn toward the west with an increase in forward speed starting later today or tonight. This westward motion is forecast to continue through Sunday. On the forecast track, the center of Lane will pass south of Kauai and Niihau later today.

Maximum sustained winds are near 65 mph (100 km/h) with higher gusts. Additional weakening is forecast through Sunday night.

Tropical-storm-force winds extend outward up to 130 miles (215 km) from the center. The estimated minimum central pressure is 992 mb (29.30 inches).

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Fri Aug 24 2018

The thunderstorms associated with Tropical Storm Lane are now far removed from the exposed low-level circulation center (LLCC). Most of this deep convection is in outer rain bands across the eastern and central Hawaiian Islands. Needless to say, severe flooding is occurring due to this, especially over the Big Island where over 40 inches of rain have fallen along parts of the windward sections. Lane continues to weaken, so taking a blend of the latest satellite intensity estimates, we have lowered the initial intensity to 55 knots.

The latest motion for this advisory is 335/3 knots. Lane is expected to continue weakening due to vertical wind shear of 25 to 30 knots. As a result, the exposed LLCC will likely track slowly north-northwestward tonight, followed by a turn toward the west on Saturday. The latest track forecast has been nudged slightly to the right through 36 hours, when it is expected to weaken to a remnant low. Assuming this low survives, it may eventually become an extratropical gale low in the vicinity of the Northwestern Hawaiian Islands by day 5.Tropical Storm Lane Distances 0200 Hours August 25 2018

KEY MESSAGES: 1. Effects from tropical storms can and do extend well from the center. Rain bands around the northern and eastern periphery of Lane are still bringing persistent flooding rainfall across parts of the state. In addition, damaging winds and isolated tornados are also possible in these rain bands. Winds will be accelerated over higher terrain, through gaps, and where winds blow downslope. Winds will also be stronger at the upper floors of high rise buildings.

FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0900Z 19.4N 158.5W   55 KT  65 MPH - Tropical Storm (W of Captain Cook, Hawaii)
 12H  25/1800Z 19.8N 159.0W   45 KT  50 MPH - Tropical Storm (NW of Captain Cook, Hawaii)
 24H  26/0600Z 19.9N 160.1W   35 KT  40 MPH - Tropical Storm (WSW of Kōloa, Hawaii)
 36H  26/1800Z 19.9N 161.6W   30 KT  35 MPH...POST-TROP/REMNT LOW (WSW of Puʻuwai, Hawaii)
 48H  27/0600Z 20.0N 163.4W   30 KT  35 MPH...POST-TROP/REMNT LOW (WSW of Puʻuwai, Hawaii)
 72H  28/0600Z 20.7N 166.2W   30 KT  35 MPH...POST-TROP/REMNT LOW (WSW of Puʻuwai, Hawaii)
 96H  29/0600Z 23.0N 168.0W   30 KT  35 MPH...POST-TROP/EXTRATROP (WNW of Puʻuwai, Hawaii)
120H  30/0600Z 27.5N 170.5W   35 KT  40 MPH...POST-TROP/EXTRATROP (ESE of Midway Atoll)

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Fri Aug 24 2018

This special advisory reduces the current intensity of Hurricane Lane  to 75 kt based on rapid weakening of the associated cloud and radar patterns observed over the past few hours, and adjusts the intensity and wind radii forecast to better agree with current trends. There are no other changes at this time. This special advisory takes the place of the 2 pm intermediate advisory.

KEY MESSAGES:

1. One should not interpret the forecast westward turn south of the islands as a lower threat to the islands. If Lane retains central core convection longer than anticipated, the westward turn would happen later, which could bring hurricane conditions to Maui County or Oahu. This solution is still plausible at this time. Regardless of whether Lane makes landfall, severe impacts are still possible and the effects can extend far to the north and east of the center of Lane.Hurricane Lane Distances 1400 Hours August 24 2018

2. Lane will remain dangerously close to the central Hawaiian Islands as a hurricane today into tonight bringing damaging winds to some areas. Terrain effects can cause strong localized acceleration of the wind through gaps and where winds blow downslope. These acceleration areas will shift with time as Lane passes near or over the islands. Winds will also be stronger at the upper floors of high rise buildings.

3. The slow movement of Lane greatly increases the threat for prolonged heavy rainfall. This is expected to lead to major flash flooding and landslides in some areas.

4. High and potentially damaging surf can be expected along exposed south facing shorelines today through Saturday, which could cause severe beach erosion in some areas.

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Fri Aug 24 2018

DISCUSSION AND OUTLOOK

At 800 AM HST (1800 UTC), the center of Hurricane Lane  was estimated by radar and satellite to be near latitude 18.8 North, longitude 158.0 West. Lane is moving toward the north near 2 mph (3 km/h), and this general motion is expected to continue through tonight. A turn toward the west is anticipated on Saturday, with an increase in forward speed. On the latest forecast track, the center of Lane will move dangerously close to portions of the central Hawaiian islands later today and tonight.

Maximum sustained winds are near 105 mph (170 km/h) with higher gusts. Some additional weakening is forecast later today and tonight, but Lane is expected to remain a dangerous hurricane as it approaches the islands. Further weakening is expected on Saturday.Hurricane Lane Distances 0800 Hours August 24 2018

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). A weather station near Waimea on the Big Island recently reported sustained winds of 45 mph (72 km/h) with gusts to 51 mph (82 km/h). The estimated minimum central pressure is 962 mb (28.47 inches).

HAZARDS AFFECTING LAND ———————-

WIND: Tropical storm conditions are already occurring on the Big Island, Maui County and Oahu. These conditions will likely persist today. Hurricane conditions are expected over some areas of Maui County and Oahu starting tonight. Tropical storm or hurricane conditions are possible on Kauai starting tonight or Saturday.

RAINFALL: Rain bands will continue to overspread the Hawaiian Islands well ahead of Lane. Excessive rainfall associated with this slow moving hurricane will continue to impact the Hawaiian Islands into the weekend, leading to catastrophic and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts up to 40 inches possible over portions of the Hawaiian Islands. Over 30 inches of rain has already fallen at a couple locations on the windward side of the Big Island.

SURF: Very large swells generated by the slow moving hurricane will severely impact the Hawaiian Islands into this weekend. These swells will produce life-threatening and damaging surf along exposed shorelines, particularly today through Saturday. In addition, a prolonged period of extreme surf will also likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 2 to 4 feet above normal tide levels along south and west facing shores near the center of Lane. The surge will be accompanied by large and destructive waves.

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Fri Aug 24 2018

Hurricane Lane  continues to signs of slow weakening due to wind shear of 20 to 30 knots from the southwest according to the latest SHIPS and UW-CIMSS analyses. There is no eye evident in satellite imagery, which is likely a result of these hostile conditions. Radar reflectivity data from the WSR-88D radars at Molokai and Kohala show the center is becoming disrupted. The latest satellite intensity estimates from HFO, JTWC, TAFB and SAB were a unanimous T5.0/90 knots, while the UW-CIMSS ADT was T5.4/100 knots. Based on a blend of these estimates, the current intensity has been lowered to 95 knots.

Lane began to turn northward Thursday evening, and the current motion is 360/4 knots. Lane continues to be steered toward the north along the western side of a mid-level ridge, which is located to the east of Hawaii. The consensus guidance continues to show a northward motion, or even a motion toward just east of due north, as the ridge builds south of Lane. The latest track has shifted to the right of the previous forecast through the next 36 hours. This more closely follows the latest consensus track guidance. Note that on this track, Hurricane Lane continues to approach the central Hawaiian Islands, so there is no reason to believe that anyone is safe in the warning area. Assuming Lane begins to weaken, and decouple before, or after, it hits the islands, the cyclone is forecast to come increasingly under the influence of the low-level easterlies and begin tracking westward. Again, the exact time when this will occur remains highly uncertain, and only a small delay in this decoupling could bring Lane farther north. This would produce considerably worse conditions over the islands. Even if Lane remains along the forecast track, significant impacts are expected in the Hawaiian Islands.

Our intensity forecast shows some additional weakening, but continues to trend on the high side of most of the intensity guidance through 72 hours due to the resilience Lane has shown during the past few days. Note that the CIRA analysis of Ocean Heat Content along the latest forecast track continues to show very high values during the next 24 hours or so. This will likely help maintain the intensity longer than might be expected with such strong shear. By early next week, it is possible that Lane will not survive the shear, and may become a remnant low by day 5.

KEY MESSAGES:

1. It is vital that you do not focus on the exact forecast track or intensity of Lane, and remain prepared for adjustments to the forecast. Although the official forecast does not explicitly indicate Lane’s center making landfall over any of the islands, this remains a very real possibility. Even if the center of Lane remains offshore, severe impacts could still be realized as they extend well away from the center.

2. Lane will pass dangerously close to the central Hawaiian Islands as a hurricane later today or tonight, and is expected to bring damaging winds. Terrain effects can cause strong localized acceleration of the wind through gaps and where winds blow downslope. These acceleration areas will shift with time as Lane passes near or over the islands. Winds will also be stronger at the upper floors of high rise buildings.

3. The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. This is expected to lead to catastrophic, life-threatening flash flooding and landslides over all Hawaiian Islands.

4. Life-threatening and damaging surf can be expected along exposed shorelines with localized storm surge exacerbating the impacts of a prolonged period of damaging surf. The prolonged period of large surf will also likely produce severe beach erosion.

FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 18.7N 158.0W   95 KT 110 MPH - Category 2 (WSW Oceanview, Hawaii)
 12H  25/0000Z 19.4N 157.9W   90 KT 105 MPH - Category 2 (WNW Oceanview, Hawaii)
 24H  25/1200Z 20.0N 158.0W   75 KT  85 MPH - Category 1 (WSW Kaho‘olawe, Hawaii)
 36H  26/0000Z 20.4N 159.0W   65 KT  75 MPH - Category 1 (WSW Honolulu, Hawaii)
 48H  26/1200Z 20.2N 160.9W   60 KT  70 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
 72H  27/1200Z 20.1N 163.6W   50 KT  60 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
 96H  28/1200Z 21.5N 166.0W   35 KT  40 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
120H  29/1200Z 25.5N 168.5W   30 KT  35 MPH - Tropical Storm (WNW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Fri Aug 24 2018

DISCUSSION AND OUTLOOKHurricane Lane Distances 0200 Hours August 24 2018

At 200 AM HST (1200 UTC), the center of Hurricane Lane was located near latitude 18.4 North, longitude 158.0 West. Lane is moving toward the north near 5 mph (8 km/h), and this general motion is expected to continue today. A turn toward the west is anticipated Saturday, with an increase in forward speed. On the latest forecast track, the center of Lane will move over, or dangerously close to portions of the main Hawaiian islands later today and tonight.

Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Lane remains a powerful category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast from later today and tonight through late Saturday, but Lane is expected to remain a dangerous hurricane as it approaches the islands.

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The estimated minimum central pressure is 956 mb (28.23 inches).

NWS Central Pacific Hurricane Center Honolulu 1100 PM HST Thu Aug 23 2018

Hurricane Lane is beginning to show some signs of slow weakening due to wind shear of over 20 knots from the southwest according to the SHIPS and UW-CIMSS analyses. There is no eye evident in satellite imagery, which is likely a result of these hostile conditions. Radar reflectivity data from the WSR-88D radars at Molokai and Kohala show the center is becoming elongated in a north to south direction. The latest satellite intensity estimates from HFO, JTWC, TAFB and SAB were a unanimous T5.5/102 knots, while the UW-CIMSS ADT was T5.7/107 knots. The current intensity is held at 105 kt based on these estimates.

The initial motion estimate is 350/5 knots, which shows a northward turn has occurred this evening. Lane continues to be steered toward the north along the western side of a mid-level ridge, which is located to the east of Hawaii. The consensus guidance continues to show a northward motion, or even a motion toward just east of due north, as the ridge builds south and possibly southwest of Lane. The latest track has shifted to the right of the previous forecast through the next 48 hours. This more closely follows the latest consensus track guidance. Note that on this track, Hurricane Lane continues to approach the Main Hawaiian Islands, so there is no reason to believe that anyone is safe in the warning area. Assuming Lane begins to weaken, and decouple before, or after, it hits the islands, Lane is forecast to come increasingly under the influence of the low level easterlies and begin tracking westward. Again, the exact time when this will occur remains highly uncertain, and only a small delay in this decoupling could bring Lane farther north. This will produce considerably worse conditions over the islands. Even if Lane remains along the forecast track, significant impacts are expected in the Hawaiian Islands.

Our intensity forecast shows some weakening, but continues to trend on the high side of the intensity guidance through 72 hours owing to how organized Lane’s core has been in recent days. Note that the CIRA analysis of Ocean Heat Content along the latest forecast track continues to show very high values during the next 24 to 36 hours, so this will likely help maintain the intensity longer than might be expected with such high shear. By early next week, it is possible that Lane will not survive the shear, and may become a remnant low by day 5.

KEY MESSAGES:

1. It is vital that you do not focus on the exact forecast track or intensity of Lane, and remain prepared for adjustments to the forecast. Although the official forecast does not explicitly indicate Lane’s center making landfall over any of the islands, this remains a very real possibility. Even if the center of Lane remains offshore, severe impacts could still be realized as they extend well away from the center.

2. Lane will pass dangerously close to the main Hawaiian Islands as a hurricane on Friday, and is expected to bring damaging winds. Terrain effects can cause strong localized acceleration of the wind through gaps and where winds blow downslope. These acceleration areas will shift with time as Lane passes near or over the islands. Winds will also be stronger at the upper floors of high rise buildings.

3. The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. This is expected to lead to major, life-threatening flash flooding and landslides over all Hawaiian Islands.

4. Large and damaging surf can be expected along exposed shorelines, especially along south and west facing coasts, with localized storm surge exacerbating the impacts of a prolonged period of damaging surf. This could lead to severe beach erosion.

FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0900Z 18.2N 158.0W  105 KT 120 MPH - Category 3 (WSW Hilo, Hawaii)
 12H  24/1800Z 19.0N 158.0W   95 KT 110 MPH - Category 2 (W Oceanview, Hawaii)
 24H  25/0600Z 19.9N 158.0W   80 KT  90 MPH - Category 1 (NW Kailua-Kona, Hawaii)
 36H  25/1800Z 20.4N 158.7W   70 KT  80 MPH - Category 1 (NW Honolulu, Hawaii)
 48H  26/0600Z 20.3N 160.1W   65 KT  75 MPH - Category 1 (NW Honolulu, Hawaii)
 72H  27/0600Z 20.3N 163.1W   55 KT  65 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
 96H  28/0600Z 21.0N 166.0W   35 KT  40 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
120H  29/0600Z 24.6N 168.4W   30 KT  35 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 PM HST Thu Aug 23 2018

DISCUSSION AND OUTLOOK

At 500 PM HST (0300 UTC), the eye of Hurricane Lane was located by radar and satellite imagery near latitude 17.8 North, longitude 157.9 West. Lane is moving toward the north-northwest near 6 mph (9 km/h). A slow general northward motion is expected to continue through Friday. A turn toward the west is expected Saturday and Sunday, with and increase in forward speed. On the forecast track, the center of Lane will move over, or dangerously close to portions of the main Hawaiian islands tonight and Friday.

Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Lane is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next 48 hours, but Lane is expected to remain a hurricane as it draws closer to the islands.Hurricane Lane Distances 1700 Hours August 23 2018

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The estimated minimum central pressure is 959 mb (28.32 inches).

HAZARDS AFFECTING LAND

WIND: Tropical storm conditions are expected on portions of the Big Island tonight and Friday. Tropical storm conditions are expected to begin over portions of Maui County tonight, with hurricane conditions expected in some areas Friday. Tropical storm conditions are expected to begin on Oahu late tonight, with hurricane conditions expected Friday into Friday night. Tropical storm or hurricane conditions are possible on Kauai on Saturday.

RAINFALL: Rain bands will continue to overspread the Hawaiian Islands well ahead of Lane. Excessive rainfall associated with this slow moving hurricane will continue to impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts in excess of 30 inches over portions of the Hawaiian Islands. Over two feet of rain has already fallen at a couple of locations on the windward side of the Big Island.

SURF: As Lane is slow-moving, large swells generated by the hurricane will severely impact the Hawaiian Islands over the next couple of days. These swells will produce very large and damaging surf along exposed west and south facing shorelines. A prolonged period of high surf will likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 2 to 4 feet above normal tide levels along south and west facing shores near the center of Lane. The surge will be accompanied by large and destructive waves.

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Thu Aug 23 2018

DISCUSSION AND OUTLOOK

At 200 PM HST (0000 UTC), the center of Hurricane Lane was located by radar and satellite imagery near latitude 17.5 North, longitude 157.8 West. Lane is moving toward the north-northwest near 6 mph (10 km/h). A slow general northward motion is expected to continue through Friday. A turn toward the west is expected Saturday and Sunday, with some increase in forward speed. On the forecast track, the center of Lane will move over, or dangerously close to portions of the main Hawaiian islands later today through Friday.

Maximum sustained winds are near 125 mph (215 km/h) with higher gusts. Lane is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next 48 hours, but Lane is expected to remain a hurricane as it draws closer to the islands.Hurricane Lane Distances 1400 Hours August 23 2018

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The estimated minimum central pressure is 953 mb (28.15 inches).

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Thu Aug 23 2018

…LANE CONTINUES TO APPROACH THE MAIN HAWAIIAN ISLANDS WITH TORRENTIAL RAINFALL ALREADY OCCURRING IN SOME AREAS…

SUMMARY OF 800 AM HST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...17.1N 157.6W
ABOUT 205 MI...330 KM SW OF KAILUA-KONA HAWAII
ABOUT 290 MI...465 KM S OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...949 MB...28.03 INCHES

DISCUSSION AND OUTLOOK – Hurricane Lane Distances 0800 Hours August 23 2018

At 800 AM HST (1800 UTC), the center of Hurricane Lane was located by satellite and radar imagery near near latitude 17.1 North, longitude 157.6 West. Lane is moving toward the northwest near 7 mph (11 km/h). A turn toward the north-northwest and little change in forward speed is expected today. A turn toward the north is anticipated tonight and Friday, as Lane’s forward motion slows. A turn toward the west is expected on Saturday and Sunday, with an increase in forward speed. On the forecast track, the center of Lane will move very close to or over the portions of the main Hawaiian islands later today through Friday.

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Lane is a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Steady weakening is forecast during the next couple of days. Lane is expected to remain a hurricane as it draws closer to the islands.

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). NOAA buoy 51002 located about 250 miles southwest of the Big Island recently reported sustained winds of 71 mph (114 km/h) and a gust of 94 mph (151 km/h). The estimated minimum central pressure is 949 mb (28.03 inches).

Hurricane Lane Hurricane Force Winds 0800 Hours August 23 2018HAZARDS AFFECTING LAND

WIND: Tropical storm conditions are expected on portions of the Big Island beginning later this morning, with hurricane conditions expected in some areas by tonight. Tropical storm conditions are expected to begin over portions of Maui County later today, with hurricane conditions expected in some areas by Friday. Tropical storm conditions are expected to begin on Oahu late tonight, with hurricane conditions expected Friday into Friday night.

RAINFALL: Rain bands from Hurricane Lane will continue to overspread the Hawaiian Islands. Excessive rainfall associated with Lane will impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts in excess of 30 inches over the Hawaiian Islands. Over 12 inches of rain has already fallen on portions of the Big Island.

SURF: As Lane is slow-moving, large swells generated by the hurricane will severely impact the Hawaiian Islands over the next couple of days. These swells will produce very large and damaging surf along exposed west and south facing shorelines. A prolonged period of high surf will likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 2 to 4 feet above normal tide levels along south and west facing shores near the center of Lane. The surge will be accompanied by large and destructive waves.

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Thu Aug 23 2018

DISCUSSION AND OUTLOOK

Hurricane Lane Track Coastal Watches-Warnings 0500 Hours August 23 2018
Hurricane Lane Track Coastal Watches-Warnings 0500 Hours August 23 2018

At 500 AM HST (1500 UTC), the center of Hurricane Lane was located near latitude 16.9 North, longitude 157.4 West. Lane is moving toward the northwest near 7 mph (11 km/h). A turn toward the north-northwest and little change in forward speed is expected today. A turn toward the north is anticipated tonight and Friday, as Lane’s forward motion slows. A turn toward the west is expected on Saturday and Sunday, with an increase in forward speed. On the forecast track, the center of Lane will move very close to or over the portions of the main Hawaiian islands later today through Friday.

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Lane is a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Steady weakening is forecast during the next couple of days. Lane is expected to remain a hurricane as it draws closer to the islands.

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). NOAA buoy 51002 located about 250 miles southwest of the Big Island recently reported sustained winds of 50 mph (80 km/h) and a gust of 64 mph (104 km/h). The estimated minimum central pressure is 949 mb (28.03 inches).

HAZARDS AFFECTING LANDHurricane Lane Distances 0500 Hours August 23 2018

WIND: Tropical storm conditions are expected on portions of the Big Island beginning later this morning, with hurricane conditions expected in some areas by tonight. Tropical storm conditions are expected to begin over portions of Maui County later today, with hurricane conditions expected in some areas by Friday. Tropical storm conditions are expected to begin on Oahu late tonight, with hurricane conditions expected Friday into Friday night.

RAINFALL: Rain bands from Hurricane Lane will continue to overspread the Hawaiian Islands. Excessive rainfall associated with Lane will impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts in excess of 30 inches over the Hawaiian Islands. Over 12 inches of rain has already fallen on portions of the Big Island.

SURF: As Lane is slow-moving, large swells generated by the hurricane will severely impact the Hawaiian Islands over the next couple of days. These swells will produce very large and damaging surf along exposed west and south facing shorelines. A prolonged period of high surf will likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 2 to 4 feet above normal tide levels along south and west facing shores near the center of Lane. The surge will be accompanied by large and destructive waves.

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Thu Aug 23 2018

HURRICANE LANE WEAKENS SLIGHTLY WHILE TRACKING TOWARD THE HAWAIIAN ISLANDS
SUMMARY OF 200 AM HST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...16.5N 157.3W
ABOUT 230 MI...370 KM SSW OF KAILUA-KONA HAWAII
ABOUT 335 MI...540 KM S OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...949 MB...28.02 INCHES

DISCUSSION AND OUTLOOK

At 200 AM HST (1200 UTC), the eye of Hurricane Lane was located by satellite and radar near latitude 16.5 North, longitude 157.3 West. Lane is moving toward the northwest near 7 mph (11 km/h). This general motion is expected to continue today, with a gradual turn toward the north-northwest. On Friday, a turn toward the north is anticipated as Lane’s forward motion slows even more. A turn back toward the west is expected on Saturday. On the forecast track, the center of Lane will move very close to or over the main Hawaiian Islands later today through Friday.

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Lane is a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next day or so, with more significant weakening thereafter. Lane is expected to remain a hurricane as it approaches the islands.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The estimated minimum central pressure is 949 mb (28.02 inches).

HAZARDS AFFECTING LAND

WIND: Tropical storm conditions are expected on portions of the Big Island beginning later this morning, with hurricane conditions expected in some areas by tonight. Tropical storm conditions are expected to begin over portions of Maui county later today, with hurricane conditions expected in some areas by Friday. Tropical storm conditions are expected to begin on Oahu late tonight, with hurricane conditions expected Friday into Friday night.

RAINFALL: Rain bands from Hurricane Lane will continue to overspread the Hawaiian Islands. Excessive rainfall associated with Lane will impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides. Lane is expected to produce total rain accumulations of 10 to 20 inches, with localized amounts in excess of 30 inches over the Hawaiian Islands.

SURF: As Lane is slow-moving, large swells generated by Lane will severely impact the Hawaiian Islands over the next couple of days. These swells will produce very large and damaging surf along exposed west and south facing shorelines. A prolonged period of high surf will likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 2 to 4 feet above normal tide levels along south and west facing shores near the center of Lane. The surge will be accompanied by large and destructive waves.

NWS Central Pacific Hurricane Center Honolulu 1100 PM HST Wed Aug 22 2018

Hurricane Lane   remains resilient in the face of increasing southwesterly wind shear, and remains a potent category 4 hurricane this evening. The cloud-filled eye continues to be surrounded by a solid ring of cold cloud tops, with lightning bursts persisting in the northern eye wall for the last several hours. The subjective Dvorak current intensity estimates from GTW/TAFB/HFO/SAB were all 6.5/127 kt for this advisory, while ADT was slightly lower. The current intensity estimate for this advisory will remain 125 kt based on a blend of these data.

Lane continues to make the long-awaited turn toward the northwest, and the forward speed has slowed, with the initial motion for this advisory estimated to be 315/6 kt. Lane has reached the western periphery of a deep-layer ridge, with a trough aloft to the northwest of Hawaii. The steering flow is relatively light and out of the south, and Lane will move northwest and north at a relatively slow speed through Friday in this environment. By 48 to 72 hours, most of the track guidance begins to show a sharp turn toward the west, as the low level circulation of Lane decouples in the face of 35 to 40 kt of shear. Exactly when this critical turn will happen is very difficult to forecast, so confidence in this portion of the track is quite low. The updated track forecast is very close to the previous but has been shifted slightly closer to the islands on days 2 and 3, when Lane will be making its closest point of approach to the islands. In deference to the HCCA, the forecast track has shifted to the right in response to the HWFI/GFSI and other members doing so, while the EMXI lies on the left hand side of the guidance envelope. Beyond 72 hours, the shallow circulation of Lane is expected to be carried westward away from the islands in the low-level trade wind flow.Hurricane Lane Distances 0200 Hours August 23 2018

Lane is beginning to move underneath increasing shear, analyzed to be near 20 kt, and latest satellite pictures indicate that this may be finally beginning to negatively impact Lane. The shear is expected to remain moderate for the first 24 to 36 hours, then become quite strong beyond 48 hours. A gradual weakening trend is shown through 48 hours, with more rapid weakening beyond that time frame. The intensity forecast remains on the high end of the guidance envelope, but follows closely all of the guidance trends that indicate significant weakening through the forecast period.

KEY MESSAGES:

1. Lane will pass dangerously close to the main Hawaiian Islands as a hurricane Thursday and Friday, and is expected to bring damaging winds. These winds can be accelerated over and downslope from elevated terrain, and will be higher in high rise buildings.

2. The slow movement of Lane also greatly increases the threat for prolonged heavy rainfall and extreme rainfall totals. This is expected to lead to life-threatening flash flooding and landslides over all Hawaiian Islands.

3. Large and damaging surf can be expected along exposed shorelines, especially along south and west facing coasts, with localized storm surge exacerbating the impacts of a prolonged period of damaging surf. 4. Do not focus on the exact forecast track or intensity of Lane, and be prepared for adjustments to the forecast. Although the official forecast does not explicitly indicate Lane’s center making landfall over any of the islands, this could still occur. Even if the center of Lane remains offshore, severe impacts could still be realized as they extend well away from the center.

FORECAST POSITIONS AND MAX WINDS
 
INIT  23/0900Z 16.3N 156.9W  125 KT 145 MPH - Category 4 (SW Hilo, Hawaii)
 12H  23/1800Z 17.2N 157.2W  120 KT 140 MPH - Category 4 (SW Hilo, Hawaii)
 24H  24/0600Z 18.4N 157.4W  115 KT 130 MPH - Category 4 (SSW Miloli'i, Hawaii)
 36H  24/1800Z 19.5N 157.6W   95 KT 110 MPH - Category 2 (SSW Honolulu, Hawaii)
 48H  25/0600Z 20.2N 158.1W   75 KT  85 MPH - Category 1 (SSW Honolulu, Hawaii)
 72H  26/0600Z 20.4N 160.5W   65 KT  75 MPH - Category 1 (SSW Puʻuwai, Hawaii)
 96H  27/0600Z 20.0N 163.0W   50 KT  60 MPH - Tropical Storm (SSW Puʻuwai, Hawaii)
120H  28/0600Z 20.5N 166.5W   40 KT  45 MPH - Tropical Storm (SSW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Wed Aug 22 2018

Hurricane LaneHurricane Lane Distances 0800 Hours August 22 2018

800 AM HST Wed Aug 22 2018
Location: 15.2N 155.7W
Max sustained: 155 MPH
Moving: WNW at 8 MPH
Min pressure: 935 MB

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Wed Aug 22 2018

SUMMARY OF 500 AM HST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...15.1N 155.3W
ABOUT 315 MI...505 KM S OF KAILUA-KONA HAWAII
ABOUT 460 MI...740 KM SSE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...155 MPH...250 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...935 MB...27.61 INCHES

Discussion
Please note that tropical cyclone operations are in effect. To incorporate the latest forecast information from the Central Pacific Hurricane Center (CPHC), public forecast updates from the Honolulu Forecast Office will be delayed to immediately follow the latest forecast package from CPHC.

Expect increasing wind speeds over the next few days as a strong high far to the north of the Hawaiian Islands interacts with Hurricane Lane, a category 5 hurricane, roughly 280 miles south of the Big Island. Lane has started to turn more towards the northwest as forecast by the Central Pacific Hurricane Center (CPHC). The forecast track for Lane continues on a northwest path today before turning more north-northwest on Thursday. Lane’s forecast track will increase the threat for hurricane force winds over the Big Island and Maui County over the next 24 to 36 hours. The Hurricane Warning was expanded this morning to include both Hawaii and Maui Counties.

The onset of damaging tropical-storm-force winds on the Big Island could start later this evening, with dangerous hurricane force winds starting in the overnight hours. In Maui County, damaging winds could begin as early as Thursday afternoon, with dangerous hurricane force winds possible starting on Thursday night. On Oahu, damaging winds could begin as early as Thursday evening, with dangerous hurricane force winds possible by Friday morning. Hurricane Warnings may need to be expanded to include other islands as Lane draws closer. The highest wind threats for the Big Island will develop along the western slopes of the island as strong and gusty down slope winds interact with mountainous terrain. The location of these damaging wind impacts will depend heavily upon the final track of Hurricane Lane.

Deep tropical moisture surrounding Lane will also drift northward ahead of the hurricane through the weekend. Extreme moisture levels surrounding Lane will create an unstable environment with muggy and humid weather conditions along with frequent showers. Heavier rain shower bands will develop with some thunderstorm activity as the extreme moisture interacts with mountainous terrain on each island. These conditions will likely lead to periods of hazardous flash flooding threatening all islands. Hence, a Flash Flood Watch remains in effect for the entire state of Hawaii through Saturday.Hurricane Lane Distances 0500 Hours August 22 2018

The combination of a deep moist unstable layer and strong low level wind shear along and to the east of the track of Lane will make tornadoes and large waterspouts a distinct possibility in the rainbands across the right semicircle of the hurricane. These continue to be included in the TCV and HLS products as an elevated threat from Oahu to the Big Island. Will be able to better refine the threat as Lane approaches.

It’s not possible to know which islands will see the worst storm effects right now due to the close proximity of the hurricane track to the Hawaiian Islands and uncertainties in Lane’s track caused by increasing wind shear through the atmosphere as it moves northward. The CPHC forecasts continue to show that all islands are at risk from direct effects from the core of Hurricane Lane. Everyone should take this hurricane very seriously and should prepare accordingly. It’s also important to expect future adjustments to the track and intensity forecast, particularly with the challenging recurvature forecast that Lane is presenting. Prepare for the worst and hope for the best.

Sunday through Tuesday, there remains a considerable amount of uncertainty in the model guidance as to when the deep moisture in the wake of Lane departs the region. The American GFS model continues to show a deep moisture plume lingering over the entire state through the weekend and into the first half of next week. While the European (ECMWF) model shows a large area of drier air moving in with the easterly trade wind flow. We will need to wait to see how fast Lane transits the Hawaiian Islands and watch for the models trending towards a more consistent solution over this time period.

Marine
Marine interests on the Big Island (leeward/southeast coasts) should finalize all preparations today as Hurricane Lane begins to approach from the south. The earliest potential onset of tropical storm force winds (34 knots or greater) across the waters around South Point and off the coast of Kona will be later today. Once these conditions are realized, it will be too late to prepare. Interests in Maui County and on Oahu should finalize all preparations by tonight and by the end of the day Thursday for Kauai.

The hurricane watch now includes the waters around Oahu and Kauai. The hurricane warning includes the leeward Maui County and Big Island waters and the southeast Big Island waters. A tropical storm warning is in place for the windward Maui County and Big Island waters.

Impacts associated with Lane through the rest of the week for the islands will include: hazardous seas, life-threatening surf (warning level), beach erosion, overwash onto vulnerable coastal roadways, and storm surge along exposed coasts/harbors of all islands as Lane passes through. See the latest coastal hazard message and local statement for additional details with regards to expected/potential impacts.

See the latest Oahu Surf Discussion (SRDHFO) for more details on surf and swell from other sources.

Watches/Warnings/Advisories
Hurricane Watch for Niihau, Kauai, Oahu.

Hurricane Watch for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel.

Hurricane Warning for Molokai, Lanai, Kahoolawe, Maui, Big Island.

Hurricane Warning for Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Tropical Storm Warning for Maui County Windward Waters, Big Island Windward Waters.

Flash Flood Watch through late Friday night for all Hawaii islands.

High Surf Warning until 6 AM HST Friday for Kona, South Big Island.

High Surf Warning from 6 AM Thursday to 6 PM HST Friday for Niihau, Kauai Windward, Kauai Leeward, Oahu South Shore, Waianae Coast, Molokai Leeward, Lanai Makai, Kahoolawe, Maui Leeward West, Maui Central Valley, Leeward Haleakala.

High Surf Advisory from noon today to 6 AM HST Thursday for Niihau, Kauai Windward, Kauai Leeward, Oahu South Shore, Waianae Coast, Molokai Leeward, Lanai Makai, Kahoolawe, Maui Leeward West, Maui Central Valley, Leeward Haleakala

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Wed Aug 22 2018

For the central North Pacific…between 140W and 180W: The Central Pacific Hurricane Center is issuing advisories on Hurricane Lane, centered about 335 miles south of Kailua-Kona, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Tue Aug 21 2018

Hurricane Lane remains an impressive hurricane this evening, with a well- developed warm eye completely surrounded by persistent cold cloud tops. Outflow remains best to the north through east and is slightly restricted elsewhere. Hurricane Hunter aircraft from the 53rd Weather Reconnaissance Squadron flew through Lane once again this evening, shortly after the last forecast package, and found winds within the northeast eyewall of 146 kt. Based on this observation, a special forecast package was issued strengthening Lane to a catagory 5 hurricane. Subjective Dvorak current intensity estimates range from 6.5/127 kt (JTWC and SAB) to 7.0/140 kt (PHFO). ADT from UW-CIMSS was 132 kt. Based on a blend of aircraft-observed central pressures and wind speeds, we will set Lane’s initial intensity to 140 kt for this package.

Initial motion for this advisory is 285/8 kt. Lane has been moving generally westward along the southern flank of a mid-level ridge during the past several days. However, this cyclone will soon begin to round the western periphery of this ridge and move into an area of relatively light steering flow. This will allow Lane to gain latitude as its forward speed diminishes. Lane is forecast to continue moving west-northwest tonight, then turn to the northwest on Wednesday, and to the north-northwest on Thursday, as it moves between the mid-level ridge to the east and a developing upper-level trough to the northwest of Hawaii. The track and intensity forecasts become increasingly uncertain after this point as most track guidance brings Lane very close to the islands, with potential interaction between Lane and the mountainous terrain of the islands. UW-CIMMS derives 13 kt of vertical shear now and this is forecast to increase to 20 to 30 kt at 48 hours, according to ECMWF SHIPS. The combination of land interaction and increasing vertical shear leads to a weakened Lane being steered to the west by the low-level trade wind flow during the later forecast periods. The new track forecast closely follows the previous one and lies between GFS and ECMWF along FSSE.

Water temperatures along the forecast track will be 27 to 28 degrees C, warm enough to support a major hurricane. Any significant weakening as Lane draws closer to the Hawaiian Islands will likely be due to increasing wind shear. Through the next 36 to 48 hours, shear is expected to remain in the 10 to 20 kt range, and we expect only slow weakening initially. At 48 hours and beyond, the forecast incorporates an expected sharp increase in shear as Lane moves closer to the large upper trough to the northwest of the main Hawaiian Islands. The new intensity forecast is very similar to the previous forecast, situated firmly between the EMXI and IVCN ensemble guidance.

KEY MESSAGES:

1. Lane is forecast to move dangerously close to the main Hawaiian Islands as a hurricane Thursday through Saturday, potentially bringing damaging winds and life-threatening flash flooding from heavy rainfall. As Lane is expected to be slow-moving as it nears the islands, it will produce large and damaging surf.

2. As Lane approaches the islands from the southeast, initial impacts will be felt on the Big Island, where a Hurricane Warning is in effect. Preparations should be rushed to completion as tropical-storm force winds are forecast to arrive by late Wednesday or early Thursday. A Hurricane Watch remains in effect for Maui County and the island of Oahu, with tropical-storm force winds possibly beginning Thursday or Thursday night.

3. Do not focus on the exact forecast track for Lane, as life- threatening weather conditions extend well away from the center of the hurricane, and impacts could be felt on any of the islands.

FORECAST POSITIONS AND MAX WINDS
 
INIT  22/0900Z 14.7N 154.5W  140 KT 160 MPH - Category 5 (SSE Hilo, Hawaii)
 12H  22/1800Z 15.4N 155.6W  135 KT 155 MPH - Category 4 (SSW Hilo, Hawaii)
 24H  23/0600Z 16.6N 156.3W  125 KT 145 MPH - Category 4 (SSW Hilo, Hawaii)
 36H  23/1800Z 17.8N 157.0W  110 KT 125 MPH - Category 3 (SSW Miloli'i, Hawaii)
 48H  24/0600Z 19.1N 157.6W   95 KT 110 MPH - Category 2 (E Miloli'i, Hawaii)
 72H  25/0600Z 21.0N 159.4W   70 KT  80 MPH - Category 1 (S Kōloa, Kauaʻi  Hawaii)
 96H  26/0600Z 21.2N 162.2W   50 KT  60 MPH - Tropical Storm (SSW Puʻuwai, Hawaii)
120H  27/0600Z 20.8N 165.3W   40 KT  45 MPH - Tropical Storm (SSW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 PM HST Tue Aug 21 2018

Hurricane Lane  remains a powerful hurricane this afternoon, with a well- developed warm eye completely surrounded by persistent cold cloud tops. The Hurricane Hunter aircraft from the 53rd Weather Reconnaissance Squadron has been flying through Lane during the day, and has provided invaluable data. The central pressure dropped around 10 mb between the 18Z and 00Z fixes, with the last eye dropsonde measuring 930 mb with 16 kt splash wind, yielding a minimum pressure estimate of 929 mb. Peak SFMR winds during this mission were 140 kt, and max flight level winds were 146 kt. Subjective Dvorak current intensity estimates range from 6.5/127 kt to 7.0/140 kt, with the latest ADT current intensity holding steady at 6.5/127 kt. Although the central pressure has dropped sharply during the last 18 hours, it is now about what one would expect for a hurricane of strong Category 4 intensity in the Central Pacific basin, and based primarily on the aircraft data the intial intensity is held at 135 kt for this advisory.

Lane has turned slightly to the WNW today, and the initial motion for this advisory is 285/8 kt. Lane has been moving generally westward to the south of a mid-level ridge during the past several days. However, this will be changing soon, as Lane begins to round the western periphery of this ridge and moves into an area of relatively light steering flow. This is expected to allow the cyclone to gain latitude as its forward speed diminishes. The hurricane is forecast to continue moving west-northwest tonight, then turn to the northwest on Wednesday, and to the north-northwest on Thursday, as it moves between the mid-level ridge to the east and a developing upper-level trough to the northwest of Hawaii. After this point, the track and intensity forecast become increasingly uncertain, as the majority of the reliable model guidance brings Lane very close to the islands with potential interaction between Lane and the mountainous terrain of the islands. This interaction combined with increasing vertical wind shear leads to a weakened Lane being steered to the west by the low-level trade wind flow during the later forecast periods. The new track forecast has been nudged slightly to left through 36 hours, then slightly to the right or closer to the islands at 72 hours, in very good agreement with the multi-model consensus HCCA.Hurricane Lane Distances 1700 Hours August 21 2018

Water temperatures along the forecast track will be sufficiently warm to support a major hurricane, and thus any significant weakening before Lane draws closer to the Hawaiian Islands will likely be due to increasing wind shear. Through the next 36 to 48 hours, shear is expected to remain light, and we expect only slow weakening as the cyclone moves over slightly cooler SSTs and may be impacted by eyewall replacement cycles. At 72 hours and beyond, the forecast anticipates a sharp increase in shear as Lane moves closer to the large upper trough to the northwest of the main Hawaiian Islands. The new intensity forecast is very similar to the previous forecast, and continues to follow the trend of the multi-model consensus IVCN. In addition to continued storm penetrations by the Hurricane Hunters of the 53rd Weather Reconnaissance Squadron, the NOAA P-3 aircraft will also be flying into Lane again this evening. The NOAA G-IV aircraft once again sampled the larger scale environment during the day to help with initialization of the forecast models.

KEY MESSAGES:

1. Lane is forecast to move dangerously close to the main Hawaiian Islands as a hurricane later this week, potentially bringing damaging winds and life-threatening flash flooding from heavy rainfall anywhere in the state. As Lane is expected to be slow-moving as it nears the islands, it will produce large and damaging surf.

2. As Lane moves up from the southeast, the earliest potential threat to land will be for the Big Island, where a Hurricane Warning is now in effect. Preparations there should be rushed to completion as tropical-storm force winds are forecast to arrive in the warning area by late Wednesday or early Thursday. A Hurricane Watch remains in effect for Maui County, and is now posted for Oahu, with tropical-storm force winds possibly beginning Thursday or Thursday night.

3. Due to a continued high degree of uncertainty on the forecast track and intensity of Lane, hurricane impacts could be felt across any of the Hawaiian Islands. It is too early to predict which, if any, of the islands are directly impacted. Remember that life threatening weather conditions can extend well away from the center of the hurricane. Interests throughout Hawaii are urged to closely monitor the progress of Lane during the next few days.

FORECAST POSITIONS AND MAX WINDS
 
INIT  22/0300Z 14.5N 154.0W  135 KT 155 MPH - Category 4 (SSE Hilo, Hawaii)
 12H  22/1200Z 15.0N 155.0W  130 KT 150 MPH - Category 4 (S Hilo, Hawaii)
 24H  23/0000Z 16.0N 156.0W  125 KT 145 MPH - Category 4 (SW Hilo, Hawaii)
 36H  23/1200Z 17.2N 156.8W  115 KT 130 MPH - Category 4 (SW Hilo, Hawaii)
 48H  24/0000Z 18.6N 157.3W  100 KT 115 MPH - Category 3 (SW Hilo, Hawaii)
 72H  25/0000Z 21.1N 158.7W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 96H  26/0000Z 21.5N 161.5W   50 KT  60 MPH - Tropical Storm (ESE Hilo, Hawaii)
120H  27/0000Z 21.0N 164.5W   40 KT  45 MPH - Tropical Storm (ESE Hilo, Hawaii)

Central Pacific Hurricane Center Honolulu HI 500 AM HST Tue Aug 21 2018

Hurricane Lane  remains a powerful hurricane this morning, with a well- developed warm eye completely surrounded by persistent cold cloud tops. Subjective Dvorak current intensity estimates were a unanimous 6.5/127 kt while ADT was in relative agreement. The initial intensity for this advisory remains at 130 kt as Lane’s satellite signature has changed little since last sampled by Hurricane Hunters and the NOAA P-3 Monday evening.

The initial motion for this advisory is 275/10 kt, with Lane continuing to be steered by a mid-level ridge to the north. Over the next day or two, Lane is expected to reach the western periphery of the ridge, and into an area of relatively light steering flow. This is expected to allow the cyclone to gain latitude as its forward speed diminishes. In this scenario, Lane will begin to make a gradual turn to the west-northwest on Wednesday, with a more decided turn toward the northwest on Thursday. After this point, the track and intensity forecast become increasingly uncertain, as a bulk of the model guidance is depicting interaction between Lane and the terrain of the islands. This interaction then leads to a weakened Lane increasingly being steered by the low-level trade wind flow. The updated track forecast is essentially an update of the previous official forecast, and lies very close to the multi-model consensus HCCA.

Water temperatures along the forecast track will be sufficiently warm to support a major hurricane, and thus any significant weakening before Lane draws closer to the Hawaiian Islands will likely be due to shear. In the short-term, shear is expected to remain light, and subtle intensity fluctuations associated with inner-core dynamics will likely lead to little overall change in intensity. By 72 hours, the forecast anticipates an increase in shear as Lane lies between the ridge to the east and a trough aloft to the northwest of the main Hawaiian Islands. The updated intensity forecast is close to the previous, and although it is on the higher end of the guidance envelope, it closely follows the trends presented by the multi-model consensus IVCN.

In addition to an increasing number of storm penetrations by the Hurricane Hunters of the 53rd Weather Reconnaissance, the NOAA G-IV will once again be sampling the larger scale environment to help forecast models better initialize. The NOAA P-3 mission slated for this morning has been scrapped as the aircraft needs to be examined after encountering strong turbulence last night.Hurricane Lane Distances 0500 Hours August 21 2018

KEY MESSAGES:

1. Lane is forecast to move dangerously close to the main Hawaiian Islands as a hurricane later this week, potentially bringing damaging winds and life-threatening flash flooding from heavy rainfall. As Lane is expected to be slow-moving as it nears the islands, it will produce large and damaging surf, mainly along exposed south and west facing shores. A Hurricane Watch has been issued for Hawaii and Maui counties, and additional Tropical Storm or Hurricane Watches may be required later today or tonight.

2. It is much too early to confidently determine which, if any, of the main Hawaiian Islands will be directly impacted by Lane. Even if the center of Lane were to remain offshore, it is important to remember that impacts from a hurricane can extend well away from the center. Interests throughout Hawaii are urged to closely monitor the progress of Lane the next couple of days.

FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 14.1N 152.3W  130 KT 150 MPH - Category 4 (SSE Hilo, Hawaii)
 12H  22/0000Z 14.4N 153.4W  125 KT 145 MPH - Category 4 (SE Hilo, Hawaii)
 24H  22/1200Z 15.0N 154.6W  120 KT 140 MPH - Category 4 (S Hilo, Hawaii)
 36H  23/0000Z 15.9N 155.6W  110 KT 125 MPH - Category 3 (S Hilo, Hawaii)
 48H  23/1200Z 17.0N 156.5W  100 KT 115 MPH - Category 3 (SW Hilo, Hawaii)
 72H  24/1200Z 19.7N 157.6W   85 KT 100 MPH - Category 2 (SW Hilo, Hawaii)
 96H  25/1200Z 21.5N 159.5W   65 KT  75 MPH - Category 1 (NE Hilo, Hawaii)
120H  26/1200Z 21.5N 163.0W   50 KT  60 MPH - Tropical Storm (SSE Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI  500 AM HST Mon Aug 20 2018

…HURRICANE LANE MAY BE A THREAT TO PORTIONS OF THE HAWAIIAN ISLANDS THIS WEEK

There are no coastal watches or warnings in effect. All interests in the Hawaiian Islands, including the Northwestern Hawaiian Islands, should continue to closely monitor the progress of Lane this week. On the current forecast track, a Tropical Storm or Hurricane Watch may be required for parts of Hawaii later today or tonight.

DISCUSSION AND OUTLOOK

At 500 AM HST (1500 UTC), the center of Hurricane Lane   was located near latitude 13.7 North, longitude 148.2 West. Lane is moving toward the west near 14 mph (22 km/h), and this general motion is expected to continue today. Lane is forecast to move westward at a slightly slower forward speed from tonight through early Tuesday, followed by a turn toward the west-northwest starting late Tuesday. Maximum sustained winds are near 125 mph (205 km/h) with higher gusts. Lane is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Little change in strength is expected through early Tuesday, with some weakening possible starting late Tuesday. Hurricane-force winds extend outward up to 30 miles (45 km) from the center and tropical-storm-force winds extend outward up to 120 miles (195 km). The estimated minimum central pressure is 961 mb (28.38 inches).Hurricane Lane Distances 0500 Hours August 20 2018

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Sun Aug 19 2018

Aircraft from the NOAA Aircraft Operation Center and the U.S. Air Force Reserves 53rd Weather Reconnaissance Squadron have been sampling Hurricane Lane this evening. The data provided by these missions have been invaluable. Based on satellite intensity estimates ranging from 87 to 102 knots and Lane’s poor representation in satellite imagery, we might have considered weakening the hurricane. Instead, the aircraft found peak flight-level and SFMR winds of 113 knots in the northwest quadrant. In addition, a dropsonde estimated surface wind of 117 knots was also found in the northwest eyewall. Based on these aircraft observations, we have increased the initial intensity to 110 knots.

The initial motion for this advisory is 275/12 knots. Lane continues tracking westward along the southern flank of a large subtropical ridge. There is still quite a bit of spread in track guidance beyond day 2 as individual models handle the erosion of the western portion of this ridge differently, due to the forecast of an upper-level trough digging down northwest of the main Hawaiian Islands later this week. The latest forecast track through 48 hours is close to the previous forecast. However, due to overwhelming evidence that the western end of the ridge will erode from days 3 through 5, we had to shift the track far to the right. The latest forecast track remains to the right of the ECMWF, which is far left of the GFS, HWRF, and consensus models.

The latest intensity forecast has been nudged up slightly compared with the previous one. This is based on the stronger initial intensity based on the aircraft, as well as the latest guidance. Lane will remain over 27-28 degree C waters through the forecast period. Shear of 10 to 15 knots is expected during the next 12 hours, followed by reduced shear during the 24 to 48 hour time periods. After that, increasing vertical shear is expected to cause steady weakening, with Lane possibly becoming a tropical storm by Day 5. This intensity forecast closely follows the IVCN consensus guidance.

Due to the large uncertainty in the future track and intensity of Lane, all interests in the Hawaiian Islands should continue to monitor the future progress of this system. Based on the latest trends in the forecast, direct impacts on the islands can not be ruled out. The latest trends in tropical cyclone wind speed probabilities also suggest that a Tropical Storm Watch may be needed for some parts of the island chain early this week.

FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0900Z 13.8N 147.0W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 12H  20/1800Z 13.9N 148.6W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 24H  21/0600Z 14.1N 150.5W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 36H  21/1800Z 14.4N 152.3W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  22/0600Z 14.7N 153.8W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  23/0600Z 15.9N 156.6W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 96H  24/0600Z 17.5N 158.5W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
120H  25/0600Z 20.0N 160.5W   60 KT  70 MPH - Category 1 (ESE Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Sun Aug 19 2018

Hurricane Lane  has not had a distinct eye in satellite imagery since late Saturday afternoon. However, a small warm spot appears to be indicative of an eye trying to form. In addition, a 1253z SSMI microwave pass shows a small eye completely surrounded by deep convection, which suggests that Lane remains rather well organized early this morning. This is despite southwesterly vertical wind shear of near 20 knots according to the latest UW-CIMSS output, while it is close to 10 knots based on the most recent SHIPS guidance. The latest subjective Dvorak intensity estimates are T5.0/90 knots from SAB, T6.0/115 knots from JTWC and T6.5/127 knots from PHFO. The most recent ADT from UW-CIMSS is now T5.4/100 knots. Based on a blend of this guidance, the latest initial intensity has been adjusted downward slightly to 105 knots for this advisory.

Lane’s initial motion for this advisory is 280/13 kt. The latest forecast track has been adjusted slightly to the right of the previous track during the 12-36 hour and 96-120 hour time periods. A large subtropical ridge to the north of Lane will continue to keep the system moving along the same general track during the next 12 hours, but at a slightly slower forward speed during the 24-72 hour time periods. A shift toward the west-northwest will likely begin beyond 72 hours as Lane approaches the western end of the ridge. The forecast models are showing this western end of the ridge will erode due to an upper-level trough digging down northwest of the Hawaiian Islands. Due to increasing uncertainty about the strength of the ridge, the model spread has increased dramatically tonight. The changes in the current forecast track were based on nudging toward the latest HWRF and HCCA guidance, as well as the GFEX and TVCN consensus models. A NOAA G-IV aircraft plans to do a synoptic sampling in the environment around the Hawaiian Islands and Lane later today. The valuable data collected during this mission will be available to better initialize the forecast models.

The latest intensity forecast has been nudged up slightly, especially during days 4 and 5. This forecast closely follows the IVCN, which shows gradual weakening from 48 through 120 hours. The ocean water temperatures will remain in the 27-28 degrees C range along the forecast track, but there may still be 10 to 15 knots of vertical wind shear through most of the forecast period. Note that the latest CIRA analysis of Ocean Heat Content shows a local maximum along the track between 72 and 96 hours. If this verifies, this may allow Lane to remain stronger than anticipated beyond day 3.

Lane is forecast to pass south of the main Hawaiian Islands Wednesday and Thursday, potentially causing local impacts as it tracks west-northwestward. Interests in these islands should watch the progress of Lane closely, since long-range track and intensity forecast errors can be large.Hurricane Lane Distances 0500 Hours August 19 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  19/1500Z 13.2N 143.5W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 12H  20/0000Z 13.5N 145.1W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 24H  20/1200Z 13.8N 147.1W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 36H  21/0000Z 14.0N 148.9W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  21/1200Z 14.2N 150.8W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  22/1200Z 14.8N 154.4W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
 96H  23/1200Z 16.0N 157.5W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
120H  24/1200Z 17.6N 160.5W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 PM PDT Sat Aug 18 2018

Hurricane Lane  remains an impressive hurricane in geostationary satellite imagery. The distinct 15 nmi-wide eye is surrounded by a ring of convection with clouds tops around -65 to -70C. The clouds tops have warmed slightly but the subjective and objective Dvorak Current Intensity (CI) numbers are unchanged so the initial intensity is maintained at 120 kt for this advisory.

The hurricane continues moving west-northwestward at about 13 kt. A large subtropical ridge to the north of Lane should keep the hurricane on a west-northwestward to westward heading during the next 24 hours. After that time, the ridge is forecast to build westward which is expected to take Lane on a more westward course between 36 and 72 hours. By day 4, Lane will be approaching the western portion of the ridge which should result in a turn back toward the west-northwest. The latest iterations of the UKMET and GFS models have shifted southward but remain along the northern side of the guidance envelope. Meanwhile, the ECMWF remains along the southern side of the guidance and also depicts a much faster forward speed. The updated NHC track forecast has been adjusted slightly southward to be near the latest consensus aids.

The intensity forecast reasoning is unchanged from the previous advisory. Lane will be moving over SSTs of 27-28 degrees Celsius throughout the forecast period, but some west to northwesterly vertical shear is expected to affect the hurricane. As a result, gradually weakening is indicated in the official forecast over the next few days. A more significant increase in shear late in the forecast period could result in a faster rate of weakening at days 4 and 5. The NHC intensity forecast is near the upper-end of the guidance during the first 24 to 48 hours, and then is closest to the HFIP corrected consensus later in the period.

Lane will move into the Central Pacific Basin very soon and this is last NHC advisory on this system. Future information on Lane can be found in advisories issued by the Central Pacific Hurricane Center beginning at 5 PM HST.

Hurricane Lane Distances 1100 Hours August 18 2018
Hurricane Lane Distances 1100 Hours August 18 2018
FORECAST POSITIONS AND MAX WINDS

INIT  18/2100Z 12.5N 139.7W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 12H  19/0600Z 12.9N 141.4W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 24H  19/1800Z 13.4N 143.6W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 36H  20/0600Z 13.7N 145.6W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  20/1800Z 13.9N 147.5W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  21/1800Z 14.1N 151.1W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 96H  22/1800Z 14.8N 154.7W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
120H  23/1800Z 15.9N 158.2W   60 KT  70 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 800 AM PDT Sat Aug 18 2018

Hurricane Lane’s  inner-core convective organization has continued to improve with satellite intensity estimates vacillating between T6.0/115 kt and T6.5/127 kt during the past 6 hours. The 15-nmi-diameter eye remains quiet distinct and is embedded within a solid ring of cloud tops colder than -70 deg C. An average of the various intensity estimates from TAFB, SAB, and UW-CIMSS ADT and SATCON support increasing the intensity to 120 kt.

The initial motion estimate is 285/13 kt. There has been little change in the models over the past couple of days, and the latest NHC guidance, especially the consensus track models, required no significant changes to the previous advisory track. The large expansive subtropical ridge to the north of the hurricane is forecast to remain intact and gradually build westward to the north of the Hawaiian Islands throughout the 120-h forecast period. As a result, Lane is expected to move west-northwestward for the next 48 hours or so, and then turn westward by day 3, maintaining that motion on days 4 and 5. The official forecast track lies close to a blend of the HCCA, TVCE, and FSSE consensus models. On the forecast track, Hurricane Lane is expected to move into the Central Pacific basin in about 9 hours at around 0000 UTC.

Although Lane will be remaining over 27.0-27.5 deg C SSTs during the forecast period, increasing westerly to northwesterly vertical wind shear to around 15 kt, along with a slightly drier mid-level environment, is expected to induce slow but steady weakening by 24 hours. Although Lane could strengthen a little more before the prolonged weakening begins, the general intensity trend should be downward. However, the rate of weakening is held a little above the intensity guidance owing to the warmer SSTs indicated by raw data than what the SHIPS model guidance is using.Hurricane Lane Distances 0500 Hours August 18 2018

FORECAST POSITIONS AND MAX WINDS

INIT  18/1500Z 12.3N 138.2W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 12H  19/0000Z 12.8N 140.0W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 24H  19/1200Z 13.4N 142.3W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 36H  20/0000Z 13.8N 144.3W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  20/1200Z 14.1N 146.3W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  21/1200Z 14.5N 150.1W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 96H  22/1200Z 14.9N 153.5W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
120H  23/1200Z 15.8N 157.0W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 AM PDT Sat Aug 18 2018

The satellite presentation of Lane   has improved significantly during the past several hours with a distinct eye surrounded by very deep convection and symmetric outflow. T-numbers from both TAFB and SAB are 6.0 on the Dvorak scale, and on this basis, the initial intensity has been increased to 115 kt. The hurricane is moving within an environment of light shear, and this should allow some additional strengthening during the next 12 to 24 hours. After that time, guidance suggests that a slight weakening should begin perhaps to a modest increase in shear. The NHC forecast does not weaken Lane as fast as indicated by the intensity guidance.

Lane continues to move toward the west-northwest or 285 degrees at 14 kt, steered by the trade winds south of the subtropical high. Since the steering pattern is not expected to change much, this general motion should continue during the next 3 to 5 days. An expected weakening of the trades should result in a small decrease in the hurricane’s forward speed. Track models are tightly clustered during the first 72 hours, and this increases the confidence in the forecast. After that time, the model agreement is not as good, resulting in a wider guidance envelope bounded by the GFS to the north and ECMWF to the south. The NHC forecast follows very closely the multi-model ensemble and the corrected consensus HCCA which are in the middle of the envelope. No significant changes were made to the previous NHC forecast.

Hurricane Lane Distances 2300 Hours August 17 2018
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FORECAST POSITIONS AND MAX WINDS

INIT  18/0900Z 12.1N 137.0W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 12H  18/1800Z 12.5N 139.0W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 24H  19/0600Z 13.0N 141.5W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 36H  19/1800Z 13.7N 143.6W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  20/0600Z 14.0N 145.5W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  21/0600Z 14.5N 149.5W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  22/0600Z 14.8N 153.1W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
120H  23/0600Z 15.7N 156.5W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 PM PDT Fri Aug 17 2018

A series of microwave overpasses and conventional visible/infrared imagery show that Lane’s  inner core continues to develop rapidly. The eye in the visible presentation has begun to clear out, and the lower frequency microwave images show a completely enclosed, solid inner convective ring. The subjective and objective T-numbers from TAFB, SAB, and UW-CIMSS, respectively, support increasing the initial intensity to 95 kt.

The intensity forecast philosophy has not changed from 6 hours ago, and Lane is still predicted to quickly strengthen to major hurricane intensity later tonight, and has the potential to become a category 4 hurricane in 24 hours. The environment certainly appears favorable enough for this 24-hour trend to occur and the hurricane regional and statistical intensity guidance reflect strengthening, but the NHC forecast is much higher than the NOAA HCCA and the IVCN consensus models during the first 24 hours. Beyond 36 hours, Lane should begin to gradually weaken in response to increasing westerly shear. The NHC forecast is similar to the previous advisory and is a blend of HCCA and IVCN at these times.

The initial motion continues to be westward or 275/14 kt. Lane is forecast to move south of a subtropical ridge in either a westward or west-northwestward direction over the next 5 days. Little change was made to the official track forecast, with only minor along-track adjustments after 72 hours, and the NHC forecast is basically a compromise of the various consensus models.Hurricane Lane Distances 1100 Hours August 17 2018

FORECAST POSITIONS AND MAX WINDS

INIT  17/2100Z 11.5N 134.1W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 12H  18/0600Z 11.7N 136.4W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 24H  18/1800Z 12.2N 139.3W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 36H  19/0600Z 12.9N 141.8W  120 KT 140 MPH - Category 4 (ESE Hilo, Hawaii)
 48H  19/1800Z 13.5N 144.1W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  20/1800Z 14.4N 148.3W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 96H  21/1800Z 14.9N 152.3W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
120H  22/1800Z 15.3N 156.2W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 800 AM PDT Fri Aug 17 2018

Tropical Storm Lane Becomes Major Hurricane Lane cloud pattern has improved significantly this morning, and the cyclone is currently undergoing rapid intensification. A warming ragged eye is now evident in GOES-15/16 IR BD-curve enhancement, and a white curved band with cold tops of -70 to -75C wraps about 90% around the cyclone’s circulation. The Dvorak satellite intensity estimates from TAFB and SAB, and the objective analysis support an increase of the wind speed to 85 kt for this advisory.

Lane appears poised for further rapid strengthening during the next 24 hours. Impressive outflow in all quadrants, warm SSTs, and the absence of earlier noted dry air intrusion all point to this scenario. The peak intensity based on the hurricane models and the statistical guidance is forecast to be within the next 24-36 hours. Afterward, the thermodynamic environment looks a little less conducive and the large-scale models as well as the statistical intensity guidance agree that increasing westerly vertical shear will induce a slow weakening trend. The official forecast is above the guidance during the first 36 hours, but is close to the HMON hurricane model, and is hedged toward a blend of the HCCA and IVCN intensity consensus models through the remaining portion of the forecast.

The initial motion is estimated to be nearly due west, or 275/14 kt. Lane should continue to move south of a subtropical ridge in either a westward or west-northwestward direction through the entire forecast period. The NHC forecast is basically an update of the previous one with just a slight adjustment to the south, and is very close to the TVCN and NOAA HCCA consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 11.2N 132.9W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 12H  18/0000Z 11.6N 135.0W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 24H  18/1200Z 12.1N 137.9W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 36H  19/0000Z 12.6N 140.7W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 48H  19/1200Z 13.3N 143.3W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  20/1200Z 14.3N 147.6W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 96H  21/1200Z 14.8N 151.8W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)
120H  22/1200Z 15.3N 155.9W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 AM PDT Fri Aug 17 2018

Lane continues to gradually strengthen. Recent microwave images show a well-defined low-level eye, but this feature is not yet apparent in geostationary satellite images. The latest satellite images show an organized central dense overcast, but convection has decreased in the outer bands. An average of the Dvorak estimates from TAFB and SAB yields an initial intensity of 70 kt.

The environmental factors suggest that continued steady or rapid strengthening is likely during the next couple of days. However, there could be some intrusions of dry air that might interrupt the rate of strengthening. Nonetheless, it seems likely that Lane will become a major hurricane within the next couple of days. By the end of the forecast period, the environment looks a little less ideal with drier air and an increase in shear likely causing slow weakening. The NHC intensity forecast is largely an update of the previous one, and it remains at the high end of the model guidance.

Hurricane Lane Distances 0500 Hours August 17 2018
Hurricane Lane Distances 0500 Hours August 17 2018

After wobbling to the north late yesterday, Lane has resumed a more westward motion at 14 kt. The hurricane is expected to move westward to west-northwestward during the next several days as it continues to be steered by a subtropical ridge to its north. There is some north-south spread amongst the models with the UKMET on the southern side of the guidance and the GFS and HWRF on the northern side. This spread appears to be associated with how much influence a mid- to upper-level low off the Baja California coast has on Lane’s steering flow. The NHC track forecast lies near the middle of the guidance envelope, favoring the various consensus models, and is slightly to the left of the previous forecast track. Lane is expected to cross into the Central Pacific basin in 36 to 48 hours.

The initial 34-kt and 50-kt wind radii have been adjusted outward based on a 0544 UTC ASCAT-B pass.

FORECAST POSITIONS AND MAX WINDS

INIT  17/0900Z 11.4N 131.4W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 12H  17/1800Z 11.8N 133.6W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
 24H  18/0600Z 12.2N 136.6W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 36H  18/1800Z 12.7N 139.4W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 48H  19/0600Z 13.4N 141.9W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  20/0600Z 14.5N 146.5W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  21/0600Z 15.0N 150.7W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
120H  22/0600Z 15.5N 155.3W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 PM PDT Thu Aug 16 2018

Satellite images indicate that Lane is trying to form a ragged eye, with an interesting mid-level mesocyclone rotating counterclockwise around the northern side of the circulation. While Dvorak estimates from TAFB/SAB indicate Lane is already a hurricane, values from microwave data are a bit lower, and the cyclone only recently started to potentially form an eye. The initial wind speed is set to 60 kt, close to the latest CIMSS SATCON figure. Further intensification is expected, and given the warm waters, low shear and moderate mid-level humidity, rapid intensification is a distinct possibility. The new NHC forecast is basically an update from the previous one, on the high side of the guidance, and could be conservative.

The initial motion estimate continues at 275/11. The synoptic pattern is well defined with a subtropical ridge persisting to the north. While the ridge could weaken somewhat in a few days, a west or west-northwestward track is anticipated throughout the forecast period. The spread in the guidance has decreased somewhat since the last advisory, and the newest model consensus has basically come in right on top of the last NHC forecast. Thus the new NHC track prediction is nearly unchanged, staying close to a blend of the dynamical model consensus and the corrected-consensus aids.

Tropical Storm Lane Distances 1100 Hours August 16 2018
Tropical Storm Lane Distances 1100 Hours August 16 2018
FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 10.6N 128.6W   60 KT  70 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  17/0600Z 10.9N 130.6W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 24H  17/1800Z 11.4N 133.4W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 36H  18/0600Z 11.9N 136.2W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 48H  18/1800Z 12.5N 139.1W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 72H  19/1800Z 13.8N 143.9W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  20/1800Z 14.8N 148.2W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
120H  21/1800Z 15.3N 152.5W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 800 AM PDT Thu Aug 16 2018

Lane appears to be intensifying this morning, with a more symmetric presentation on satellite imagery and pulsing deep convection near the center. A recent SSMI/S microwave pass indicates that an inner core is trying to form, although it isn’t well defined yet. The current intensity estimates continue to display a large spread, ranging from the overnight scatterometer data at low-end tropical- storm strength, from hurricane strength in the TAFB Dvorak estimate. The initial wind speed is set to 50 kt with the increased organization, and this remains a low confidence estimate.

While so far Lane has only been slowly intensifying, the large-scale environment appears favorable for more significant intensification to occur soon, especially with current signs of a primitive inner core. Thus the wind speed forecast will maintain the quick strengthening from the previous forecast, and there remains a significant chance that rapid intensification will occur during the next few days. The biggest change from yesterday is that more of the global models are indicating that westerly shear could affect Lane in the central Pacific, so more weakening is shown at day 5. Otherwise, the new NHC intensity forecast is very close to the previous one and is on the higher side of the guidance.Tropical Storm Lane Distances 0500 Hours August 16 2018

The initial motion estimate is 275/11. The subtropical ridge to the north of Lane should continue to be the dominant steering mechanism, forcing the tropical cyclone to move westward or west-northwestward for the next several days. While the model spread is low in the short range, it notably increases by days 4/5. The GFS-based guidance is showing Lane move slower than the rest of the guidance, which allows the eastern periphery of the ridge to erode due to an inverted mid-level trough, and consequently a more poleward motion of the cyclone. The ECMWF and UKMET show Lane moving faster and basically missing any influence of that trough, causing the storm to move faster to the west. There are no strong signals pointing me to either solution, so the official forecast follows the trend of the consensus, which ends up slightly west of the previous forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  16/1500Z 10.6N 127.6W   50 KT  60 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  17/0000Z 10.8N 129.4W   60 KT  70 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  17/1200Z 11.2N 132.1W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 36H  18/0000Z 11.7N 134.9W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 48H  18/1200Z 12.2N 137.6W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  19/1200Z 13.5N 142.7W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  20/1200Z 14.7N 147.3W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
120H  21/1200Z 15.3N 151.5W   95 KT 110 MPH - Category 3 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 AM PDT Thu Aug 16 2018

The latest satellite images suggest that Lane   is getting better organized with its cloud pattern now consisting of a central dense overcast feature and curved bands over the western semicircle. There is a large spread in the intensity estimates tonight. All of the Dvorak-based estimates have increased to 3.5/55 kt. However, an ASCAT pass around 0600 UTC showed maximum winds of only 35 kt. Since Lane is a compact system, it is possible that the resolution of ASCAT is not sufficient to capture its maximum winds, therefore, the initial intensity is held at 45 kt as a compromise of these data. It should be noted that this is a low confidence initial intensity estimate.

Lane is now moving due westward at 10 kt steered by the flow on the south side of a deep-layer ridge. The global models all show a mid- to upper-level trough off the Baja California peninsula cutting off and moving westward during the next few days. This feature will weaken the ridge a little, and that should cause Lane to make a slight turn to the west-northwest in a couple of days. The models are tightly clustered, and the NHC track forecast lies near the middle of the guidance envelope. Based on this forecast, Lane is expected to cross into the Central Pacific basin this weekend.Tropical Storm Lane Distances 2300 Hours August 15 2018

The environmental conditions appear quite favorable for Lane to strengthen. During the next several days, the wind shear near Lane is expected to be less than 10 kt, humidity values relatively high, and SSTs sufficently warm. Therefore, steady or even rapid strengthening appears likely. The NHC intensity forecast continues to lean toward the higher end of the model guidance, and shows Lane becoming a hurricane in 12 to 24 hours, and a major hurricane within the next few days. This forecast is in best agreement with the HCCA model.

FORECAST POSITIONS AND MAX WINDS

INIT  16/0900Z 10.4N 126.4W   45 KT  50 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  16/1800Z 10.6N 128.3W   55 KT  65 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  17/0600Z 10.9N 131.0W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 36H  17/1800Z 11.4N 133.7W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 48H  18/0600Z 11.8N 136.4W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  19/0600Z 13.1N 141.6W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  20/0600Z 14.4N 146.3W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
120H  21/0600Z 15.1N 150.3W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 800 PM PDT Wed Aug 15 2018

Overall, Lane’s cloud pattern has become a little better organized this evening. Modest east-northeasterly shear, however, along with some drier air, appears to be undercutting the diffluent outflow above 300 mb and is impinging the north through northeast portion of the cyclone. An outer deep convective curved band, on the other hand, is now developing over most of the eastern half of the system. The surface center is also located a bit further in the northern edge of an expanding, colder, central dense overcast. The initial intensity is increased to 45 kt, and is based on a compromise of the TAFB and SAB subjective Dvorak satellite intensity estimates (T3.0), and a 2205 UTC SATCON analysis (51 kt).

Little change has been made to the previous intensity forecast, and it still shows a rapid increase of nearly 55 kt in 48 hours based on the Deterministic to Probabilistic Statistical Rapid Intensification Index (DTOPS) which indicates a 67 percent chance of RI occuring during this particular period. The NHC forecast is weighed heavily on a blend of the COAMPS-TC and the HFIP Corrected Consensus Approach model (HCCA), and indicates Lane intensifying into a category 3 hurricane in 3 days.

Tropical Storm Lane Distances 1700 Hours August 15 2018
Tropical Storm Lane Distances 1700 Hours August 15 2018

Lane’s motion is estimated to be westward, or 265/11 kt, a little to the left of due west, and is being steered by a broad mid-level ridge to its north-northwest. The large-scale models continue to show the ridge weakening in 2 days in response to a southwestward and westward retrograding cut-off mid-level low currently located southwest of the Baja California coast. At that time, the cyclone should gradually turn west-northwestward and continue in this general direction through the remaining period of the forecast. The official forecast is very close to the previous one, with only minor along-track adjustments, and sides with the HCCA and TVCN consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  16/0300Z 10.4N 125.6W   45 KT  50 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  16/1200Z 10.4N 127.4W   60 KT  70 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  17/0000Z 10.7N 129.8W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 36H  17/1200Z 11.1N 132.5W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 48H  18/0000Z 11.6N 135.2W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  19/0000Z 12.9N 140.6W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  20/0000Z 14.3N 145.4W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
120H  21/0000Z 15.2N 149.3W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 PM PDT Wed Aug 15 2018

Satellite images indicate that Lane is strengthening. The central dense overcast continues to grow, with a large banding feature in the western semicircle and expanding outflow in most quadrants. ASCAT data recently showed maximum winds of about 40 kt, so that will be the initial wind speed, which is also near a blend of the latest Dvorak estimates from TAFB and SAB.

While the latest microwave data indicate that the inner core of Lane remains loosely organized, the large-scale environment appears to be favorable for intensification. Low shear, warm waters of 27.5-28C, and moderate levels of mid-level moisture all support strengthening at a higher rate than climatology. However, since the inner core is not well established yet, the intensity forecast will be held just below rapid strengthening (30 kt in 24 h) for day 1. There is still a strong signal for that threshold to be met in the day 2-3 period from the DTOPS rapid intensification index, so the forecast will remain for a major hurricane to form during that time. This forecast is close to a blend of the latest NOAA-HCCA and FSSE corrected consensus models.Tropical Storm Lane Diatances 1100 Hours August 15 2018

FORECAST POSITIONS AND MAX WINDS

INIT  15/2100Z 10.6N 124.5W   40 KT  45 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  16/0600Z 10.5N 126.2W   50 KT  60 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  16/1800Z 10.7N 128.4W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)
 36H  17/0600Z 11.1N 130.9W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
 48H  17/1800Z 11.6N 133.6W   95 KT 110 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  18/1800Z 12.6N 138.7W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  19/1800Z 14.0N 143.6W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
120H  20/1800Z 15.2N 148.2W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)

The storm continues to move just south of due west, now at about 11 kt. The synoptic pattern is well established with a subtropical ridge expected to only slightly weaken in the medium-range period, causing a slight west-northwestward turn in the central Pacific. While the overall spread has increased in the 1200 UTC guidance, the latest model consensus has barely budged since the previous advisory, although it does fit the recent westward trend. The latest official track forecast is again adjusted in that direction, close to the eastern Pacific track model consensus TVCE.

NWS National Hurricane Center Miami FL 1100 AM PDT Wed Aug 15 2018

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on recently upgraded Tropical Storm Lane , located over 1000 miles southwest of the southern tip of the Baja California peninsula.

NWS National Hurricane Center Miami FL 800 AM PDT Wed Aug 15 2018

The latest satellite imagery shows that the cyclone continues to become better organized with a growing central dense overcast along with ample banding features. Dvorak estimates range from 30 to 40 kt, and with the increased organization since the last advisory, the initial wind speed is set to 35 kt.Tropical Storm Lane Distances 0500 Hours August 15 2018

Further intensification is likely over the next few days as Lane  encounters a conducive large-scale environment consisting of low shear and fairly warm waters. Rapid strengthening is a distinct possibility after the cyclone forms an inner core, which could take a day or so given that there is still some drier air in the eastern semicircle. The DTOPS rapid intensification index indicates a high probability of significant strengthening over the next 3 days, with over a 70 percent chance of a 65-kt increase during that time. Given that some of the guidance (FSSE and HMON) are even higher than that, this seems like a reasonable forecast and is indicated below. The new NHC forecast is raised from the last advisory, and is close to a blend of the previous forecast and the corrected-consensus guidance. Continuity prevents a higher forecast, but Lane seems destined to eventually become a category-4 hurricane like Hector.

The storm continues to move just south of due west at about 12 kt. The subtropical ridge to the north of Lane is forecast to weaken slightly over the next few days, which will likely steer the cyclone to the west or west-northwest throughout the period. There is very little spread in the guidance, with the most notable change since the last advisory being a small shift to the southwest. The latest official track forecast is adjusted in that direction, and is not too far from the latest model consensus. Given the tightly packed guidance, this appears to be a high-confidence forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  15/1500Z 10.7N 123.6W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  16/0000Z 10.6N 125.5W   45 KT  50 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  16/1200Z 10.7N 127.7W   55 KT  65 MPH - Tropical Storm (ESE Hilo, Hawaii)
 36H  17/0000Z 11.0N 130.0W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 48H  17/1200Z 11.5N 132.4W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  18/1200Z 12.6N 137.6W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 96H  19/1200Z 13.9N 142.2W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)
120H  20/1200Z 15.0N 146.5W  105 KT 120 MPH - Category 3 (ESE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 AM PDT Wed Aug 15 2018

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Depression Fourteen-E, located over 1000 miles southwest of the southern tip of the Baja California peninsula.

NWS National Hurricane Center Miami FL 200 AM PDT Wed Aug 15 2018

Satellite images indicate that the depression is gradually getting better organized with deep convection increasing near the center and in curved bands over the western semicircle. The initial intensity remains 30 kt, in agreement with the Dvorak classifications from TAFB and SAB, but it would not be surprising if the system was a little stronger.

The depression continues to move just south of due west at about 12 kt. A deep-layer ridge situated to the north of the cyclone should keep the system moving on a general westward path at about the same forward speed during the next couple of days. After that time, the models suggest that a mid- to upper-level low will cut off and cause a break in the ridge. This change in the flow pattern should cause the tropical cyclone to move toward the west-northwest in the 3- to 5-day time frame. The models have generally shifted slightly to the left this cycle, and the NHC forecast has been nudged in that direction.

The environmental conditions appear conducive for the cyclone to strengthen during the next several days with the wind shear expected to remain low, less than 10 kt, mid-level humidities fairly high, and SSTs marginally warm. The intensity models respond to these favorable conditions, and all of them now show the system becoming a hurricane within the next few days. The NHC intensity forecast follows that theme, and shows a faster rate of strengthening than the previous forecast. This prediction lies closest to the HCCA and ICON models.

FORECAST POSITIONS AND MAX WINDS

INIT  15/0900Z 10.8N 122.3W   30 KT  35 MPH - Tropical Storm (SE Hilo, Hawaii)
 12H  15/1800Z 10.6N 124.2W   40 KT  45 MPH - Tropical Storm (SE Hilo, Hawaii)
 24H  16/0600Z 10.6N 126.4W   45 KT  50 MPH - Tropical Storm (SE Hilo, Hawaii)
 36H  16/1800Z 10.8N 128.6W   55 KT  65 MPH - Tropical Storm (SE Hilo, Hawaii)
 48H  17/0600Z 11.1N 130.8W   65 KT  75 MPH - Category 1 (SE Hilo, Hawaii)
 72H  18/0600Z 12.3N 135.6W   80 KT  90 MPH - Category 1 (SE Hilo, Hawaii)
 96H  19/0600Z 13.8N 140.1W   90 KT 105 MPH - Category 1 (SE Hilo, Hawaii)
120H  20/0600Z 15.2N 144.1W   90 KT 105 MPH - Category 1 (SE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 PM PDT Tue Aug 14 2018

For the eastern North Pacific…east of 140 degrees west longitude: 1. A well-defined low pressure system is located about 1050 miles southwest of the southern tip of the Baja California peninsula. Associated thunderstorm activity continues to gradually increase in organization, and a tropical depression is likely to form tonight or Wednesday while the disturbance moves westward at 10 to 15 mph.

* Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…near 100 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Mon Aug 13 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. A large low pressure system is located about 950 miles southwest of the southern tip of the Baja California peninsula. Shower and thunderstorm activity continues to become better organized, and
environmental conditions are expected to be conducive for a tropical depression to form during the next couple of days days while the disturbance moves westward at 10 to 15 mph.
* Formation chance through 48 hours…medium…60 percent.
* Formation chance through 5 days…high…90 percent.

2. A weak low pressure area located about 1250 miles west-southwest of the southern tip of the Baja California peninsula continues to produce disorganized showers and thunderstorms. Although some slow
development is still possible during the next day or so, the low is forecast to reach cooler waters by late Tuesday or Wednesday, which would limit further development chances.
* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Mon Aug 13 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. Showers and thunderstorms have continued to become more concentrated near the center of a low pressure system located about 900 miles south-southwest of the southern tip of the Baja California peninsula. Environmental conditions are conducive for gradual development, and a tropical depression is expected to form during the next 2 to 3 days while the disturbance moves westward at 10 to 15 mph. * Formation chance through 48 hours…medium…40 percent.
* Formation chance through 5 days…high…70 percent.

2. A broad low pressure area located about 1250 miles west-southwest of the southern tip of the Baja California peninsula is producing showers and a few thunderstorms. While this system is showing some signs of organization, the low is forecast to reach cooler waters by Tuesday afternoon, which would limit further development chances. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Mon Aug 13 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. Showers and thunderstorms have continued to become more concentrated near the center of a low pressure system located about 900 miles south-southwest of the southern tip of the Baja California peninsula. Environmental conditions are conducive for gradual development, and a tropical depression is expected to form during the next 2 to 3 days while the disturbance moves westward at 10 to 15 mph. * Formation chance through 48 hours…medium…40 percent.
* Formation chance through 5 days…high…70 percent.

2. A broad low pressure area located about 1250 miles west-southwest of the southern tip of the Baja California peninsula is producing showers and a few thunderstorms. While this system is showing some signs of organization, the low is forecast to reach cooler waters by Tuesday afternoon, which would limit further development chances. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Mon Aug 13 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. Showers and thunderstorms have become more concentrated in association with a low pressure area located about 850 miles south-southwest of the southern tip of the Baja California peninsula. Environmental conditions are conducive for slow development, and a tropical depression could form late this week while the disturbance moves westward at 10 to 15 mph. * Formation chance through 48 hours…low…20 percent.
* Formation chance through 5 days…medium…50 percent.

2. A broad low pressure area located a little over 1200 miles west-southwest of the southern tip of the Baja California peninsula is producing showers and thunderstorms. While this system is showing some signs of organization, the low is forecast to reach cooler waters by tomorrow afternoon, which would limit further development chances. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Mon Aug 13 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. Disorganized showers and thunderstorms continue in association with a tropical wave located about 850 miles south-southwest of the southern tip of the Baja California peninsula. Environmental conditions are forecast to become a little more conducive for development by the middle part of the week, and a tropical depression could form late this week while the disturbance moves westward at 10 to 15 mph. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium…40 percent.

2. A broad low pressure area located about 1200 miles west-southwest of the southern tip of the Baja California peninsula is producing disorganized showers and thunderstorms. Some development of this system is possible during the next day or two before upper-level winds and water temperatures become less conducive. * Formation chance through 48 hours…low…20 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Sun Aug 12 2018

For the eastern North Pacific…east of 140 degrees west longitude:

1. A tropical wave located about 750 miles south-southwest of Manzanillo, Mexico, continues to produce a large area of cloudiness and disorganized shower activity. Upper-level winds are expected to become more conducive for development by the middle of next week, and a tropical depression could form by that time while the disturbance moves westward farther away from the coast of Mexico. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…50 percent.

2. Limited shower activity is occurring in association with Post-Tropical Cyclone Kristy, located about 1400 miles west of the southern tip of the Baja California peninsula. The low is expected to move slowly westward over colder waters, and regeneration into a tropical cyclone is not expected. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…near 0 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Sat Aug 11 2018

For the eastern North Pacific…east of 140 degrees west longitude:

A tropical wave located about 600 miles south of Manzanillo, Mexico, continues to produce a large area of cloudiness, showers, and thunderstorms. This system has shown some increase in organization since yesterday, and additional development is possible over the next couple of days. Upper-level winds appear to become more conducive for development by the middle of next week, and a tropical depression could form by that time while the wave moves westward farther away from the coast of Mexico. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium...50 percent.

Showers and a few thunderstorms have redeveloped in association with Post-Tropical Cyclone Kristy, located about 1400 miles west of the southern tip of the Baja California peninsula. However, the low is expected to continue moving westward over cold waters, and regeneration into a tropical cyclone is not expected. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…10 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Sat Aug 11 2018

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

A weak area of low pressure located about midway between the west coast of Africa and the Lesser Antilles is producing a minimal amount of showers and thunderstorms. Significant development of this system appears unlikely, due to unfavorable environmental conditions, while it moves slowly westward during the next couple of days. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…10 percent.

A non-tropical area of low pressure is forecast to form over the central Atlantic in a couple of days. The low could gradually acquire subtropical or tropical characteristics while it meanders through the middle of next week. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Sat Aug 11 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Kristy, located more than a thousand miles west of the southern tip of the Baja California peninsula.

1. A concentrated area of showers and thunderstorms centered a little more than 600 miles south of Manzanillo, Mexico is associated with a tropical wave. This activity is beginning to show some signs of organization. Only limited development is anticipated for the next day or two, but a tropical depression could form by the middle of next week while the disturbance moves westward well away from the coast of Mexico. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium...40 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Sat Aug 11 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Tropical Storm Kristy, located more than a thousand miles west of the southern tip of the Baja California peninsula.

1. A concentrated area of showers and thunderstorms centered a little more than 600 miles south of Manzanillo, Mexico is associated with a tropical wave. This activity has become a little better organized since yesterday, and conditions appear to be favorable for some development of this system by the middle of next week while the disturbance moves westward away from the coast of Mexico. * Formation chance through 48 hours…low…near 10 percent. * Formation chance through 5 days…low…30 percent.

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