Tropical Storm Hector

Hurricane Hector Track 2300 Hours August 12 2018
Hurricane Hector Track 2300 Hours August 12 2018
Hurricane Hector Satellite 1400 Hours August 12 2018
Hurricane Hector Satellite 1400 Hours August 12 2018

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Sun Aug 12 2018

Hector’s appearance has severely degraded according to satellite imagery this evening. The low-level circulation center (LLCC) is becoming almost entirely exposed, and the last area of deep convection has nearly dissipated, leaving behind mainly cirrus debris. This is not unexpected given the vertical wind shear of 11 to 14 kt from the south-southwest according to the latest SHIPS and UW-CIMSS analyses. The most recent subjective Dvorak intensity estimates are T3.5/55 knots from PHFO and SAB, and T3.0/45 knots from JTWC based on a shear pattern. The UW-CIMSS ADT estimate is T2.5/35 knots. Based on all of this guidance, we are lowering the initial intensity to 55 knots for this advisory.

Since we can easily monitor the movement of the exposed LLCC in satellite imagery, the initial motion is set at 295/15 knots. The track forecast has been adjusted slightly from the previous one. Surprisingly, the latest model guidance remains tightly clustered through 72 hours, with the spread in the forecast tracks increasing on Days 4 and 5. Hector is expected to continue on a west-northwest track along the eastern periphery of a retrograding upper-level low located just west of the International Date Line near Longitude 173E. As this low aloft continues to move west, an upper level ridge is forecast to build north of the Hector. This will likely keep the tropical storm moving toward the west-northwest during the next 48 hours. A gradual turn toward the northwest is expected in around 72 hours, followed by a turn toward the north on days 4 and 5, as Hector rounds the western end of the ridge.Hurricane Hector Distances 2300 Hours August 12 2018

The latest forecast track remains very close to the consensus guidance. Note that since the system is sheared, the forecast track is also close to the TABS through 48 hours. Based on the latest forecast track, Hector will likely cross the International Dateline into the Northwestern Pacific on Monday. The latest intensity forecast is very close to the previous forecast package. The forecast indicates additional weakening is expected during the next 12 hours. Based on the current appearance and the continuing southwesterly shear of 10 to 15 knots, it is likely this will occur. The forecast guidance continues to show the shear may relax within 18 to 24 hours, but the system will likely be weaker by this time and will be moving over cooler sea surface temperatures. The intensity guidance is in fairly good agreement through 36 hours, so confidence during this portion of the forecast is fairly good. Most of the intensity guidance levels off during the 36 through 48 hour time frame, while the SHIPS guidance and GFS indicate some unrealistic strengthening. The main weakening trend is on days 3 and 4. In addition, Hector is forecast to transition to an extratropical gale low in about 96 hours.

Since the current track continues to shift more toward the west, the Tropical Storm Watch has been discontinued for Kure Atoll and Midway Atoll. Note that large breaking waves are still likely to persist along the Northwestern Hawaiian Islands from tonight into Monday due to the southeast swell generated by Hector.

FORECAST POSITIONS AND MAX WINDS
 
INIT  13/0900Z 24.9N 178.8W   55 KT  65 MPH - Tropical Storm (W Hilo, Kawaii)
 12H  13/1800Z 25.9N 178.9E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 24H  14/0600Z 27.0N 175.9E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 36H  14/1800Z 28.0N 172.8E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 48H  15/0600Z 29.2N 169.8E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 72H  16/0600Z 32.0N 164.5E   45 KT  50 MPH - Tropical Storm (W Hilo, Kawaii)
 96H  17/0600Z 36.0N 162.5E   35 KT  40 MPH - Tropical Storm (W Hilo, Kawaii)
120H  18/0600Z 42.0N 164.5E   35 KT  40 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Sun Aug 12 2018
Location: 24.2N 176.3W
Max sustained: 75 MPH
Moving: WNW at 17 MPH
Min pressure: 988 MB

DISCUSSION AND OUTLOOK

At 200 PM HST (0000 UTC), the center of Hurricane Hector was located near latitude 24.2 North, longitude 176.3 West. Hector is moving toward the west-northwest near 17 mph (28 km/h) and this motion is expected to continue through Monday. Maximum sustained winds are near 75 mph (120 km/h) with higher gusts. Hector is forecast to weaken to a tropical storm later today or tonight. Hurricane-force winds extend outward up to 10 miles (20 km) from the center and tropical-storm-force winds extend outward up to 85 miles (140 km). The estimated minimum central pressure is 988 mb (29.18 inches).Hurricane Hector Distances 1400 Hours August 12 2018

HAZARDS AFFECTING LAND

SURF: Hector is producing swell that will affect portions of the Northwestern Hawaiian Islands over the next couple of days. The large southeast seas and swells will peak between Maro Reef and Lisianski Island later today and tonight, and across Pearl and Hermes, Midway Atoll and Kure Atoll tonight through Monday.

WIND: Tropical Storm conditions are possible across Pearl and Hermes Atoll through early tonight, and are possible across Kure Atoll and Midway Atoll tonight and Monday.

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Sun Aug 12 2018

Hector continues to weaken this morning due to south-southwesterly shear of around 16 kt over the system as analyzed by the latest UW-CIMSS shear analysis. The low level circulation center in visible satellite imagery appears to be on the south side of the deepest convection. The latest subjective Dvorak intensity estimates were 4.0 (65 knots) from PHFO and SAB, and 3.5 (55 knots) from JTWC. The satellite presentation clearly shows that weakening is ongoing, but given the persistent deep convection near the low level circulation center and necessary spin down time needed as these systems weaken, will only lower the initial intensity to 65 knots with this advisory. The initial motion is set at 300/15 knots.

The latest model guidance remains tightly clustered through 72 hours, with the spread in the track guidance increasing considerably at 96 and 120 hours. Hector is expected to continue on a west-northwest track today on the eastern periphery of an upper level low to the west of the International Date Line. The system is expected to make a turn to a more westerly direction tonight, and continue on this course through Wednesday as an upper level ridge builds north of the system. A turn toward the northwest and eventually north is then expected Wednesday night through Friday as Hector rounds the southwest periphery of the upper level ridge. The new official forecast track is very close to the consensus guidance as well as the track from the previous advisory.Hurricane Hector Distances 1100 Hours August 12 2018

The intensity forecast calls for slow weakening of Hector over the next 12 to 24 hours as the system will remain in southwesterly shear of around 15 kt. The shear is forecast to decrease beyond 24 hours, but the system will likely have weakened by this time and will be moving over cooler sea surface temperatures. The intensity guidance is in fairly good agreement through 36 hours, so confidence during this portion of the forecast is fairly good. There is quite a bit of spread in the intensity guidance beyond 36 hours however, with the HWRF and CTCI models continuing to show Hector re-intensifying a bit during the 48 through 72 hour time frame. This seems really aggressive given the state the hurricane is in at the moment and with the continued weakening forecast. As a result, the official intensity forecast calls for slow weakening through Monday morning, with Hector becoming a Tropical Storm later today or tonight. Beyond 24 hours the forecast intensity has been held steady through 48 hours, with slow weakening expected at the end of the forecast period as Hector transitions over to an extratropical system.

Probabilities for tropical storm force winds reaching the Northwestern Hawaiian Islands have decreased since the previous advisory. A Tropical Storm Watch remains in effect for Kure Atoll and Midway Atoll and waters between Midway Atoll and Pearl and Hermes Atoll. The Tropical Storm Watch has been discontinued for the area from Lisianski Island to Pearl and Hermes Atoll. If Hector continues to weaken as expected, and the forecast track to the west-northwest continues, the Tropical Storm Watches currently in effect may be canceled later today or tonight.

FORECAST POSITIONS AND MAX WINDS
 
INIT  12/2100Z 23.7N 175.7W   65 KT  75 MPH - Category 1 (W Hilo, Kawaii)
 12H  13/0600Z 24.8N 177.9W   55 KT  65 MPH - Tropical Storm (W Hilo, Kawaii)
 24H  13/1800Z 26.2N 179.0E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 36H  14/0600Z 27.0N 175.9E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 48H  14/1800Z 28.1N 172.8E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 72H  15/1800Z 30.4N 166.5E   45 KT  50 MPH - Tropical Storm (W Hilo, Kawaii)
 96H  16/1800Z 33.7N 162.7E   40 KT  45 MPH - Tropical Storm (W Hilo, Kawaii)
120H  17/1800Z 38.0N 161.9E   35 KT  40 MPH...POST-TROP/EXTRATROP

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Sun Aug 12 2018

For the central North Pacific…between 140W and 180W:

The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector, located about 875 miles west of Lihue, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Sat Aug 11 2018

The satellite presentation of Hector has degraded significantly from the previous advisory, as the system is getting hammered by around 30 knots of south-southwesterly shear as indicated by the latest UW-CIMSS shear analysis. This has resulted in rapid weakening of the system this evening. The latest subjective Dvorak intensity estimates were 5.0 (90 knots) from PHFO and JTWC, while SAB came in with 4.5 (77 knots). Meanwhile the Advanced Dvorak Technique from UW-CIMSS was 5.2 (95 knots). Given the current satellite presentation of the system, the initial intensity is set on the lower side of the estimates at 80 knots. The poor satellite presentation is making it very difficult to locate the center of Hector, but an 0516Z SSMIS pass was helpful in determining its location. The initial motion is set at 315/13 knots.

The latest model guidance remains tightly clustered through 72 hours, with increasing spread by 96 hours and a considerable amount of spread by 120 hours. Hector is expected to track off to the northwest tonight and Sunday on the eastern periphery of an upper level low to the west of the International Date Line. The system is expected to make a turn more westerly Sunday night and continue on this course through Wednesday as an upper level ridge builds north of the system. A turn toward the northwest and eventually north is then expected by Thursday and Friday as Hector rounds the southwest periphery of the upper level ridge. Given the latest guidance trends and the current northwesterly motion of the system, the official forecast track was nudged slightly north of the previous advisory through 48 hours, which is very close to the model consensus. Beyond 48 hours, the forecast track is very close to the model consensus and GFEX tracks, which is also close to the track from the previous advisory.

Hurricane Hector Distances 0200 Hours August 12 2018
Hurricane Hector Distances 0200 Hours August 12 2018

The intensity forecast calls for fairly rapid weakening of Hector over the next 24 hours as the system will be in a very hostile environment under 20 to 30 knots of southwesterly shear. The shear is forecast to decrease beyond 24 hours, but the system will likely have weakened considerably by this time and will be moving over marginal sea surface temperatures between 79 and 81 degrees Fahrenheit. There is quite a bit of spread in the intensity guidance beyond 24 hours, with the HWRF continuing to show rapid weakening of Hector through 36 hours while the intensity in the consensus guidance levels off. The dynamical models then show an increase in intensity between 48 hours and 96 hours, while the consensus guidance remains pretty much steady state. The official forecast will show continued rapid weakening through 24 hours, then show a leveling off in the intensity from 36 to 72 hours with gradual weakening beyond 72 hours.

Given the close approach Hector is expected to make to the Northwestern Hawaiian Islands on Sunday and Monday, a Tropical Storm Watch remains posted for the area from Lisianski Island to Pearl and Hermes Atoll, as well as fore Midway and Kure Atolls.

FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0900Z 22.1N 172.9W   80 KT  90 MPH - Category 1 (W Hilo, Kawaii)
 12H  12/1800Z 23.4N 174.8W   75 KT  85 MPH - Category 1 (W Hilo, Kawaii)
 24H  13/0600Z 24.9N 177.4W   65 KT  75 MPH - Category 1 (W Hilo, Kawaii)
 36H  13/1800Z 26.0N 179.7E   60 KT  70 MPH - Tropical Storm (W Hilo, Kawaii) 
 48H  14/0600Z 26.8N 176.8E   60 KT  70 MPH - Tropical Storm (W Hilo, Kawaii)
 72H  15/0600Z 28.6N 170.4E   60 KT  70 MPH - Tropical Storm (W Hilo, Kawaii)
 96H  16/0600Z 31.1N 165.1E   55 KT  65 MPH - Tropical Storm (W Hilo, Kawaii)
120H  17/0600Z 34.3N 162.4E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 PM HST Sat Aug 11 2018

Hector (see Friday video below) has lost its visible eye this afternoon, while retaining a bit of a warm spot in infrared imagery. Satellite loop continues to show that Hector feels the effects of southerly vertical shear, with great outflow to the north but restricted outflow elsewhere. Subjective Dvorak current intensity estimates range from 5.0/90 kt (PHFO) to 5.5/102 kt(JTWC/SAB). ADT from UW-CIMSS is 87 kt. Based on a blend of these numbers, the initial intensity for this advisory is set at 95 kt, the same as the previous initial intensity.

The initial motion for Hector remains at 310/12 kt as this system continues its motion toward the northwest between a ridge to the northeast and a mid- to upper-level low to the northwest. As the ridge remains stationary and the low becomes better developed, we expect a slight increase in forward speed as well as a continued northwest motion. By Monday, the ridge will build to the north of Hector, inducing a slight turn toward the west that will persist until the end of the forecast period, at which time Hector is expected to make a turn back toward the northwest. The updated track is almost identical to the previous one, with a small nudge to the right added to the informal track after 120 hours to remain within the guidance envelope.Hurricane Hector Distances 1700 Hours August 11 2018

Southerly shear is expected to increase into the 25 to 30 kt range through 18 hours, according to SHIPS, prompting us to maintain the fairly rapid weakening trend through 24 hours. After that, shear is forecast to decrease, but SSTs are forecast to steadily decrease as well. SHIPS wants to keep Hector at hurricane strength through 120 hours, while HWRF has changed its tune by weakenening Hector to tropical storm status by 24 hours before restrengthening on days 4 and 5. In contrast, ECMWF gradually weakens Hector to a remnant low on day 5. The official forecast is a mix between HWRF and and ECMWF, describing a fairly rapid weakening through 24 hours, followed by more gradual weakening through the rest of the forecast period.

Given the close approach to the Northwestern Hawaiian Islands Hector is forecast to make on Sunday and Monday, a Tropical Storm Watch remains posted for the area from Lisianski Island to Pearl and Hermes Atoll. A Tropical Storm Watch is now also in effect for Midway and Kure Atolls.

FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0300Z 21.2N 171.8W   95 KT 110 MPH - Category 2 (W Hilo, Kawaii)
 12H  12/1200Z 22.4N 173.5W   85 KT 100 MPH - Category 2 (W Hilo, Kawaii)
 24H  13/0000Z 23.9N 176.0W   75 KT  85 MPH - Category 1 (W Hilo, Kawaii)
 36H  13/1200Z 25.0N 178.8W   70 KT  80 MPH - Category 1 (W Hilo, Kawaii)
 48H  14/0000Z 26.0N 178.2E   70 KT  80 MPH - Category 1 (W Hilo, Kawaii)
 72H  15/0000Z 28.1N 172.2E   65 KT  75 MPH - Category 1 (W Hilo, Kawaii)
 96H  16/0000Z 30.4N 166.2E   55 KT  65 MPH - Tropical Storm (W Hilo, Kawaii)
120H  17/0000Z 35.5N 162.1E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Sat Aug 11 2018

LOCATION…19.7N 170.4W ABOUT 210 MI…340 KM NNW OF JOHNSTON ISLAND ABOUT 495 MI…795 KM SSE OF LISIANSKI ISLAND

MAXIMUM SUSTAINED WINDS…120 MPH…195 KM/H PRESENT MOVEMENT…NW OR 310 DEGREES AT 12 MPH…19 KM/H MINIMUM CENTRAL PRESSURE…957 MB…28.26 INCHES

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for… * Portions of the Papahanaumokuakea Marine National Monument from Lisianski Island to Pearl and Hermes Atoll. A Tropical Storm Watch means that tropical storm conditions are possible across the watch area within 48 hours. Interests elsewhere in the Northwestern Hawaiian Islands on Midway and Kure Atolls should monitor the progress of Hector . For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu Hawaii.Hurricane Hector Distances 0800 Hours August 11 2018

DISCUSSION AND OUTLOOK

At 800 AM HST (1800 UTC), the center of Hurricane Hector was located near latitude 19.7 North, longitude 170.4 West. Hector is moving toward the northwest near 12 mph (19 km/h). While this general motion is expected over the next couple of days, an increase in forward speed is expected later today. Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Hector is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Steady weakening is forecast over the next day or two, with a slower rate of weakening expected thereafter. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The estimated minimum central pressure is 957 mb (28.26 inches). HAZARDS

AFFECTING LAND

SURF: Large north swells generated by Hector will gradually decline on Johnston Island today. Hector is producing swell that will begin to arrive over portions of the Northwestern Hawaiian Islands today, and continue for the next couple of days. The large southeast seas and swells will peak between Maro Reef and Lisianski Island tonight and Sunday, and across Pearl and Hermes, Midway Atoll and Kure Atoll late Sunday into Monday.

WIND: Tropical Storm conditions are possible across Lisianski Island and Pearl and Hermes Atoll on Sunday.

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Sat Aug 11 2018

Hector’s  ragged and cloud-filled eye is surrounded by a nearly solid ring of very cold cloud tops, but the overall structure of the cyclone is diminishing. Outflow has become increasingly restricted in the southern semicircle as Hector moves closer to southerly shear associated with a developing low aloft to the west-northwest. Subjective Dvorak current intensity estimates from HFO/SAB/PGTW ranged from 5.5/105 kt to 6.0/115 kt, while Final-T numbers were as low as 4.5/77 kt. Based on a blend of these values, and the assumption that a weakening of a cyclone’s wind field will lag the satellite presentation, the initial intensity for this advisory is maintained at 105 kt.

The initial motion estimate for this advisory is 300/10 kt. The steering environment is characterized by a mid-level ridge to the northeast and a mid- to upper-level low to the northwest. As the ridge remains stationary and the low becomes better developed, a slight turn toward the northwest is expected in the short term, with an increase in forward speed. By Monday, the ridge will build to the north of Hector, inducing a slight turn toward the west that will persist until the end of the forecast period, at which time Hector is expected to make a turn back toward the northwest. The updated forecast track was once again nudged to the left of the previous forecast and lies close to HWFI/TVCN guidance. Note that FSSE guidance appears to have problems with the International Date Line that is causing errors with the tracker.

Hurricane Hector Distances 0500 Hours August 11 2018
Hurricane Hector Distances 0500 Hours August 11 2018

A fairly rapid rate of weakening is expected over the next 36 hours as south to southwesterly shear increases to near 30 kt, with a slower rate of weakening expected thereafter as shear relaxes. After 24 hours, SSTs along the forecast track will steadily decrease from the current 28C, but are still expected to be near 26C on day 3, and near 25C on day 5. With weaker shear beyond 36 hours, SHIPS indicates little change in intensity, keeping Hector a minimal hurricane through day 5. The HWRF indicates the upcoming shear increase will weaken Hector to a minimal tropical storm within 48 hours before it re-intensifies on days 4 and 5. The official forecast is close to the previous forecast and closely follows the IVCN consensus, with increased guidance spread in the later forecast periods leading to decreased confidence.

Given the close approach to the Northwestern Hawaiian Islands on Sunday and Monday, a Tropical Storm Watch remains posted for the area from Lisianski Island to Pearl and Hermes Atoll. Interests on Midway and Kure Atolls should monitor continue to monitor the progress of Hector.

FORECAST POSITIONS AND MAX WINDS
 
INIT  11/1500Z 19.3N 170.1W  105 KT 120 MPH - Category 3 (W Hilo, Kawaii)
 12H  12/0000Z 20.5N 171.6W   90 KT 105 MPH - Category 3 (W Hilo, Kawaii)
 24H  12/1200Z 22.2N 174.0W   80 KT  90 MPH - Category 1 (W Hilo, Kawaii)
 36H  13/0000Z 23.7N 176.6W   70 KT  80 MPH - Category 1 (W Hilo, Kawaii)
 48H  13/1200Z 24.8N 179.3W   65 KT  75 MPH - Category 1 (W Hilo, Kawaii)
 72H  14/1200Z 26.6N 174.9E   60 KT  70 MPH - Tropical Storm (W Hilo, Kawaii)
 96H  15/1200Z 29.0N 169.0E   55 KT  65 MPH - Tropical Storm (W Hilo, Kawaii)
120H  16/1200Z 32.0N 164.0E   50 KT  60 MPH - Tropical Storm (W Hilo, Kawaii)
 
$$

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Sat Aug 11 2018

For the central North Pacific…between 140W and 180W:

The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector, located about 695 miles west-southwest of Lihue, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Fri Aug 10 2018

For the central North Pacific…between 140W and 180W:

The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector, located about 600 miles west-southwest of Lihue, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Fri Aug 10 2018

Hector  has been showing some signs of fluctuations of intensity early this morning. The eye was less distinct earlier this morning, but it is showing signs of becoming somewhat better defined during the past couple of hours. All of the satellite fix agencies (PHFO, SAB and JTWC) continued to indicate the subjective Dvorak intensity estimates are T6.0/115 kt. The latest UW/CIMSS ADT is T5.8/110 kt. Based on a blend of this guidance, the initial intensity will be kept at 115 kt.

Hector’s latest movement appears to toward the west-northwest, or 285 degrees, at 14 kt. This motion is expected to continue today as Hector continues to be steered by a mid-level ridge located to the north-northeast. The western end of this ridge is forecast to weaken as a mid-level low pressure system develops near the International Dateline from tonight through this weekend. This is expected to result in a turn toward the northwest starting tonight, and continuing into early next week. The current forecast mostly follows the previous advisory package though 72 hours. After that, the latest forecast track is shifted slightly to the left on days 4 and 5. These subtle changes in the track were due to nudging toward the HWRF, as well as the consensus models, such as TVCN and GFEX.Hurricane Hector Distances 0500 Hours August 10 2018

The latest intensity forecast is indicating nearly steady state conditions today and tonight. Note that there may be slight fluctuations in intensity during the next 12 to 24 hours, but Hector will likely remain a powerful hurricane through tonight. After that, we are expecting gradual weakening from 36 through 48 hours. The weakening trend is more significant beyond 48 hours as Hector moves into an area of increasing vertical wind shear, as well as cooler water temperatures. The current intensity forecast is also in line with HWRF, HMON, and CTC2, which have verified the best so far. These models also show a faster weakening after 48 hours, but this forecast again shows a more conservative weakening trend for now.

As a result of Hector’s west-northwest motion, the outer winds from the hurricane will be far removed from Johnston Island. Therefore, the Tropical Storm Watch is being discontinued. However, the latest wind speed probabilities continue to show portions of the Northwestern Hawaiian Islands, including Midway and Kure Atolls and the Papahanaumokuakea Marine National Monument west of French Frigate Shoals may require a Tropical Storm Watch later today or tonight. It is also possible that if Hector does not weaken this weekend as forecast, a Hurricane Watch may be required for some areas. Note that there is no threat to any of the main Hawaiian Islands from Kauai to the Big Island.

FORECAST POSITIONS AND MAX WINDS
 
INIT  10/1500Z 17.7N 165.9W  115 KT 130 MPH - Category 4 (WSW Hilo, Kawaii)
 12H  11/0000Z 18.5N 167.7W  115 KT 130 MPH - Category 4 (WSW Hilo, Kawaii)
 24H  11/1200Z 19.8N 169.8W  115 KT 130 MPH - Category 4 (WSW Hilo, Kawaii)
 36H  12/0000Z 21.3N 171.7W  105 KT 120 MPH - Category 3 (WSW Hilo, Kawaii)
 48H  12/1200Z 23.3N 173.8W   90 KT 105 MPH - Category 2 (WSW Hilo, Kawaii)
 72H  13/1200Z 27.0N 178.5W   70 KT  80 MPH - Category 1 (WSW Hilo, Kawaii)
 96H  14/1200Z 30.5N 176.5E   55 KT  65 MPH - Tropical Storm (WSW Hilo, Kawaii)
120H  15/1200Z 33.5N 173.0E   45 KT  50 MPH - Tropical Storm (WSW Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Fri Aug 10 2018

At 200 AM HST (1200 UTC), the center of Hurricane Hector was located near latitude 17.6 North, longitude 165.2 West. Hector is moving just north of due west near 16 mph (26 km/h). A gradual turn toward the west-northwest is expected later this morning, followed by a northwestward motion from tonight through Saturday. On the latest forecast track, the center of Hector is expected to pass more than 100 miles north of Johnston Island later today.Hurricane Hector Distances 0200 Hours August 10 2018

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Hector is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional strengthening is possible this morning, followed by gradual weakening from later today through Saturday night.

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 110 miles (175 km). The estimated minimum central pressure is 951 mb (28.09 inches).

HAZARDS AFFECTING LAND

SURF: Swells generated by Hector should begin to impact Johnston Island later this morning. This will likely produce large and dangerous waves along portions of the island from later today through tonight.

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Thu Aug 09 2018

At 200 PM HST (0000 UTC), the eye of Hurricane Hector was located near latitude 17.0 North, longitude 162.4 West. Hector is moving toward the west near 16 mph (26 km/h) and this general motion is expected to continue through today. A gradual turn toward the west-northwest is expected tonight through late Friday. On the forecast track, the center of Hector is expected to pass 100 to 200 miles north of Johnston Island late Friday.

Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Hector is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Little change in strength is forecast through Friday night, with slow weakening afterward.Hurricane Hector Distances 1400 Hours August 9 2017

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 90 miles (150 km). The estimated minimum central pressure is 957 mb (28.26 inches). HAZARDS AFFECTING LAND ———————- SURF: Swells generated by Hector should begin to impact Johnston Island tonight. This will likely produce large and dangerous waves along portions of the island from late tonight through Friday night.

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Thu Aug 09 2018

Hurricane Hector has continued westward, 275/14 kt, well south of the main Hawaiian Islands and has maintained a well-defined eye over the past several hours. In the satellite imagery the system is a bit asymmetric with the upper level outflow better in the northeastern semicircle and slightly restricted on the southwestern side. Subjective Dvorak intensity estimates came in at 5.5/102 kt from PHFO, SAB, and JTWC. CIMSS ADT was 5.7/107 kt at 1800 UTC. Based on a blend of these values, the current intensity for this package is held at 105 kt.

Hector has been moving westward to the south of a solid mid-level ridge. The ridge is forecast to weaken as a low pressure system cuts off near the Dateline over the next couple of days. This should result in a gradual turn toward the west-northwest over the next day or so, followed by a more northwestward track. The latest objective aids are in good agreement with this scenario but are a bit north of the previous package. Thus, the forecast has been adjusted north accordingly and is close to the dynamical model consensus.

In the near term, there do not appear to be any environmental factors that will result in significant intensity changes. The SSTs along the track are expected to be in the 27C to 28C range and vertical shear should remain weak over the next couple of days. SHIPS guidance indicates that shear should increase after 48 hours. Beyond day 3, the adjustment of the track forecast north of the previous track takes Hector across the SST gradient into cooler waters. Thus, the intensity forecast shows a little more aggressive weakening than the previous forecast with Hector weakening to a tropical storm on day 5. This trend is consistent with ICON. Note that HWRF and HMON have been the best intensity aids so far and show a more aggressive weakening than the official forecast, especially after 48 hours.

A Tropical Storm Watch remains in effect for Johnston Island. If the expected turn toward the west-northwest does not occur, tropical storm conditions are possible there starting late Friday. Elsewhere, interests in the Northwestern Hawaiian Islands, including Midway and Kure Atolls and the Papahanaumokuakea Marine National Monument west of Laysan Island should monitor the progress of Hector. This does not include the main Hawaiian Islands.Hurricane Hector Distances 1100 Hours August 9 2017

FORECAST POSITIONS AND MAX WINDS
 
INIT  09/2100Z 16.9N 161.5W  105 KT 120 MPH - Category 3 (WSW Hilo, Kawaii)
 12H  10/0600Z 17.2N 163.6W  105 KT 120 MPH - Category 3 (WSW Hilo, Kawaii)
 24H  10/1800Z 17.9N 166.2W  105 KT 120 MPH - Category 3 (WSW Hilo, Kawaii)
 36H  11/0600Z 18.9N 168.6W  105 KT 120 MPH - Category 3 (WSW Hilo, Kawaii)
 48H  11/1800Z 20.3N 170.7W   95 KT 110 MPH - Category 2 (WSW Hilo, Kawaii)
 72H  12/1800Z 23.8N 175.0W   85 KT 100 MPH - Category 2 (WSW Hilo, Kawaii)
 96H  13/1800Z 27.0N 179.5E   65 KT  75 MPH - Category 1 (WSW Hilo, Kawaii)
120H  14/1800Z 31.0N 174.5E   55 KT  65 MPH - Tropical Storm (WSW Hilo, Kawaii

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Thu Aug 09 2018

The eye of Hector warmed and become much better defined in infrared satellite imagery overnight. As a result, the satellite fix agencies provided subjective Dvorak satellite-based intensity estimates of near 102 kt. The latest ADT estimate from UW-CIMSS is near 105 kt. Based on the improved appearance of the hurricane, we have increased the initial intensity to 105 kt for this advisory. Hector has been traveling nearly due west early this morning, so the latest motion is 270/14 kt. Hector is expected to continue moving westward along the southern periphery of a strong mid-level ridge located north of the main Hawaiian Islands. This ridge is forecast to move little during the next day or two.

Hector is expected to gradually turn toward the west-northwest in 24-36 hours as it reaches the southwestern periphery of the ridge. After that, a gradual turn toward the northwest is possible during 48-72 hours. The latest track forecast lies close to the previous forecast and a tightly-packed guidance envelope through day 3. Increased guidance spread on days 4 and 5 arises due to differences in the forecast strength and position of the ridge, and a developing low aloft to the northwest of Hector. The latest forecast adjusts the track slightly to the right of the previous forecast. This is based on the latest consensus guidance, including the TVCN and GFEX, as well as the HWRF.

Since Hector has strengthened slightly overnight, we see no obvious impediments to it maintaining about the same intensity during the next 36 hours. The ICON, SHIPS, and HWRF seem to agree with this scenario. After that, some gradual weakening is possible from days 2 through 5 as it starts to encounter cooler water temperatures and increasing southwesterly shear. A Tropical Storm Watch has been issued for Johnston Island. If the expected turn toward the west-northwest does not occur, tropical storm conditions are possible there starting late Friday. Elsewhere, interests in the Northwestern Hawaiian Islands, including Midway and Kure Atolls and the Papahanaumokuakea Marine National Monument west of Pearl/Hermes, should monitor the progress of Hector. Note, this does not include the main Hawaiian Islands.

Hurricane Hector Distances 0500 Hours August 9 2017 Hurricane Hector Distances 0500 Hours August 9 2017
Hurricane Hector Distances 0500 Hours August 9 2017 Hurricane Hector Distances 0500 Hours August 9 2017

 

FORECAST POSITIONS AND MAX WINDS
 
INIT  09/1500Z 16.6N 160.1W  105 KT 120 MPH - Category 3 (SW Hilo, Kawaii)
 12H  10/0000Z 16.8N 162.2W  105 KT 120 MPH - Category 3 (SW Hilo, Kawaii)
 24H  10/1200Z 17.2N 164.9W  105 KT 120 MPH - Category 3 (SW Hilo, Kawaii)
 36H  11/0000Z 17.9N 167.5W  105 KT 120 MPH - Category 3 (SW Hilo, Kawaii)
 48H  11/1200Z 18.9N 169.9W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 72H  12/1200Z 21.5N 174.0W   90 KT 105 MPH - Category 2 (SW Hilo, Kawaii)
 96H  13/1200Z 25.0N 179.0W   80 KT  90 MPH - Category 1 (SW Hilo, Kawaii)
120H  14/1200Z 28.5N 176.0E   65 KT  75 MPH - Category 1 (SW Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Wed Aug 08 2018

Based on reflectivity data from the South Point WSR-88D radar om the Big Island, microwave images, and satellite data, it appeared that Hector went through an eyewall replacement cycle late this afternoon. Since this reorganization of the hurricane appears to be complete now, the eye of Hector has warmed and become much better defined in infrared satellite imagery during the past few hours. As a result, the satellite fix agencies provided subjective Dvorak satellite-based intensity estimates ranging from 102 kt to 115 kt. The latest ADT estimate from UW-CIMSS is near 105 kt. Based on a blend of all of this input, we are maintaining the initial intensity for this advisory at 100 kt. Hector has been traveling nearly due west this evening, so the latest motion is 270/14 kt. Note that Hector passed about 25 n mi south of buoy 51004 earlier this evening. Wind gusts of 66 kt and seas up to 30 feet were observed at this buoy around 0700z this evening.

Hurricane Hector Distances 2300 Hours August 8 2017
Hurricane Hector Distances 2300 Hours August 8 2017

Hector is expected to continue moving westward along the southern periphery of a strong mid-level ridge located north of the main Hawaiian Islands. This ridge is forecast to move little through Thursday. Hector is expected to gradually turn toward the west-northwest in 36-48 hours as it reaches the southwestern periphery of the ridge. After that, a more pronounced turn toward the northwest is anticipated after 72 hours. The updated track forecast lies close to the previous forecast and a tightly-packed guidance envelope through day 3. Increased guidance spread on days 4 and 5 arises due to differences in the forecast strength and position of the ridge, and a developing low aloft to the northwest of Hector. The latest forecast adjusts the track slightly to the right of the previous forecast. This is based on the latest consensus guidance, including the TVCN and GFEX, as well as the HWRF.

Since Hector appears to be maintaining its intensity after the eyewall replacement cycle, we have opted to keep its intensity steady through 48 hours. After that, some gradual weakening is possible from days 3 through 5 as it starts to encounter cooler water temperatures and increasing southwesterly shear. Interests on Johnston Island should monitor the progress of Hector. Based on the latest wind speed probabilities, a Tropical Storm Watch may be required for Johnston Island on Thursday.

FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0900Z 16.6N 158.5W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 12H  09/1800Z 16.7N 160.7W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 24H  10/0600Z 17.0N 163.4W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 36H  10/1800Z 17.5N 166.1W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 48H  11/0600Z 18.4N 168.7W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 72H  12/0600Z 20.6N 173.0W   95 KT 110 MPH - Category 2 (SW Hilo, Kawaii)
 96H  13/0600Z 24.0N 178.0W   85 KT 100 MPH - Category 2 (SW Hilo, Kawaii)
120H  14/0600Z 27.5N 177.5E   70 KT  80 MPH - Category 1 (SW Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Thu Aug 9 2018

For the central North Pacific…between 140W and 180W: The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector, located about 340 miles south-southwest of Honolulu, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Wed Aug 08 2018

Hector’s satellite presentation has fluctuated since the previous advisory, with the eye briefly becoming indiscernible in traditional infrared imagery before appearing again. The U.S. Air Force Reserve 53rd Weather Reconnaissance Squadron has been penetrating Hector’s core this morning, and found some decrease in observed winds (with maximum flight level winds of 106 kt), while the surface pressure changed little since last night. Based on a combination of the aircraft data and subjective and objective satellite-based intensity estimates, the initial intensity for this advisory is set at 100 kt, with Hector maintaining major hurricane status.Hurricane Hector Distances 1100 Hours August 8 2017

The initial motion for this advisory is 270/14 kt, with Hector tracking due west to the south of a mid-level ridge centered to the distant north. The ridge will move little through Thursday, and the high-confidence short-term track forecast keeps Hector moving steadily west well to the south of the main Hawaiian islands. Given the reduced wind threat to the Big Island, the Tropical Storm Warning has been discontinued for Hawaii County. Hector is expected to gradually gain latitude after 48 hours as it reaches the southwestern periphery of the ridge, with a more decided turn toward the northwest expected after 72 hours. The official track forecast lies close to the previous forecast and a tightly-packed guidance envelope through day 3. On days 4 and 5, the official forecast has been shifted to the right of the previous, close to FSSE and TVCN, which are indicating a sharper poleward turn as a low aloft develops to the northwest of Hector.

Radar and microwave data indicate that an eyewall replacement cycle may be underway, with a secondary eyewall noted in a 1707 UTC SSMI image. If this occurs, some weakening and changes to the wind field may occur in the short-term as the inner eye wall collapses. However, the overall environment in which Hector is embedded will remain conducive for the maintenance of a strong hurricane as shear will be light and SSTs sufficiently warm through Friday. Therefore, the intensity forecast indicates little change through 36 hours, with some weakening in the longer range as southwesterly shear potentially increases.

FORECAST POSITIONS AND MAX WINDS
 
INIT  08/2100Z 16.5N 155.3W  100 KT 115 MPH - Category 3 (S Hilo, Kawaii)
 12H  09/0600Z 16.6N 157.6W   95 KT 110 MPH - Category 2 (SW Hilo, Kawaii)
 24H  09/1800Z 16.7N 160.4W   95 KT 110 MPH - Category 2 (SW Hilo, Kawaii)
 36H  10/0600Z 17.0N 163.2W   95 KT 110 MPH - Category 2 (SW Hilo, Kawaii)
 48H  10/1800Z 17.5N 165.9W   90 KT 105 MPH - Category 2 (SW Hilo, Kawaii)
 72H  11/1800Z 19.5N 171.0W   90 KT 105 MPH - Category 2 (E Johnson Atoll)
 96H  12/1800Z 22.6N 176.0W   85 KT 100 MPH - Category 2 (ESE Midway Atoll)
120H  13/1800Z 25.0N 180.0E   80 KT  90 MPH - Category 1 (ESE Midway Atoll)

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Wed Aug 08 2018

...MAJOR HURRICANE HECTOR PASSING SOUTH OF THE BIG ISLAND...
 
SUMMARY OF 800 AM HST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...16.5N 154.5W
ABOUT 225 MI...360 KM SSE OF HILO HAWAII
ABOUT 400 MI...645 KM SE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...960 MB...28.35 INCHES

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:Hurricane Hector Distances 0800 Hours August 8 2017

A Tropical Storm Warning is in effect for… * Hawaii County A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area today. Interests on Johnston Island should monitor the progress of Hector. For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu Hawaii.

DISCUSSION AND OUTLOOK

At 800 AM HST (1800 UTC), the eye of Hurricane Hector was located by aircraft and radar near latitude 16.5 North, longitude 154.5 West. Hector is moving toward the west near 15 mph (24 km/h), and this motion is expected to continue into Friday. On the forecast track, the center of Hector will pass about 150 miles south of the Big Island this afternoon, and about 300 miles south of Oahu tonight. Remember, the effects of a hurricane are far reaching and can extend well away from the center. Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Hector is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some slight weakening is forecast during the next couple of days. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km). The estimated minimum central pressure is 960 mb (28.35 inches).

HAZARDS AFFECTING LAND

SURF: Swells generated by Hector will likely produce large and dangerous surf along southeast and east facing shores of the Big Island today. Large surf is also expected along east facing shores of Maui.

WIND: Tropical storm conditions are expected across portions of the Big Island today as the core of Hector passes to the south. The strongest winds are expected downslope from mountains, across higher terrain, over headlands, and through gaps.

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Tue Aug 08 2018

500 AM HST Wed Aug 08 2018
Location: 16.4N 153.9W
Max sustained: 125 MPH
Moving: W at 16 MPH
Min pressure: 956 MB

Hurricane Hector Distances 0500 Hours August 8 2018
Hurricane Hector Distances 0500 Hours August 8 2018

At 500 AM HST (1500 UTC), the center of Hurricane Hector was located near latitude 16.4 North, longitude 153.9 West. Hector is moving toward the west near 16 mph (26 km/h), and this motion is expected to continue through Thursday night. Maximum sustained winds are near 125 mph (205 km/h) with higher gusts. Hector is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some slight weakening is forecast during the next couple of days. However, Hector will likely remain a powerful hurricane through Thursday night. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km). The estimated minimum central pressure is 956 mb (28.23 inches).

SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for… * Hawaii County A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area later today. Interests on Johnston Island should monitor the progress of Hector. For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Tue Aug 07 2018

Hurricane Hector continues to have an impressive appearance in infrared satellite this evening. However, there are some signs of weakening as the eye has become somewhat less distinct. A reconnaissance aircraft from the U.S. Air Force Reserve 53rd Weather Reconnaissance Squadron continues to send valuable data from Hector. The peak surface wind found by the aircraft was 108 kt. In addition, the central pressure had filled to 956 mb during the most recent pass through the center. Based on these observations, we have weakened the hurricane to 110 kt for this advisory. Data from this aircraft also confirm that Hector has turned more westward. The long term motion is now 275/14 kt.

The track philosophy has not changed, so the adjustments to the previous forecast have been minor through the next 2 days. After 48 hours, Hector is expected to begin gradually gaining latitude as it passes around the southwestern edge of an anticyclone, and is under increasing influence from an upper-level trough to the west of longitude 170W.

Hector remains in a low shear environment, but it is moving across marginally warm sea surface temperatures. This is expected to cause a gradual weakening trend during the next day or so. Afterward, the low-shear environment continues, but water temperatures gradually warm, which may allow Hector to restrengthen a bit. Toward the end of the forecast period, increasing wind shear may start to affect the hurricane, and the official forecast continues to show a weakening trend. The overall confidence in the intensity forecast is somewhat low due to these competing factors. The latest intensity forecast continues to closely follow the ICON guidance, which shows Hector remaining stronger than the SHIPS guidance indicates.Hurricane Hector Distances 0200 Hours August 8 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  08/0900Z 16.5N 152.2W  110 KT 125 MPH - Category 3 (SSE Hilo, Kawaii)
 12H  08/1800Z 16.7N 154.6W  110 KT 125 MPH - Category 3 (S Hilo, Kawaii)
 24H  09/0600Z 16.8N 157.6W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 36H  09/1800Z 16.9N 160.6W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 48H  10/0600Z 17.2N 163.5W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 72H  11/0600Z 18.0N 169.0W  100 KT 115 MPH - Category 3 (N Johnson Atoll)
 96H  12/0600Z 20.0N 173.5W  100 KT 115 MPH - Category 3 (NW Johnson Atoll)
120H  13/0600Z 22.5N 178.5W   95 KT 110 MPH - Category 2 (SW Midway Atoll)

NWS Central Pacific Hurricane Center Honolulu HI 200 PM HST Tue Aug 07 2018

SUMMARY OF 200 PM HST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...16.4N 150.0W
ABOUT 410 MI...660 KM ESE OF SOUTH POINT HAWAII
ABOUT 615 MI...990 KM ESE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 17 MPH...27 KM/H
MINIMUM CENTRAL PRESSURE...952 MB...28.11 INCHES

At 200 PM HST (0000 UTC), the eye of Hurricane Hector  was located near latitude 16.4 North, longitude 150.0 West. Hector is moving toward the west near 17 mph (27 km/h), and this general motion is expected to continue through Thursday. On the forecast track, the center of Hector is expected to pass less than 200 miles south of the Big Island on Wednesday. Remember, the effects of a hurricane are far-reaching and can extend well away from the center.

Hurricane Hector Distances 1400 Hours August 7 2018
Hurricane Hector Distances 1400 Hours August 7 2018

Data from the Air Force Reserve Hurricane Hunters indicate maximum sustained winds remain near 130 mph (215 km/h) with higher gusts. Hector is still a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast over the next couple of days.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km). The estimated minimum central pressure is 952 mb (28.11 inches).

HAZARDS AFFECTING LAND ———————- SURF: Swells generated by Hector are expected to reach southeast and east facing shores of the Big Island and eastern Maui late today, likely becoming large and dangerous by late tonight and Wednesday. WIND: Tropical storm conditions are possible across portions of Hawaii County on Wednesday as the core of Hector passes south of the Big Island.

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Tue Aug 7 2018

For the central North Pacific…between 140W and 180W:

The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector , located about 500 miles east-southeast ofHilo, Hawaii. 800 AM HST Tue Aug 07 2018
Location: 16.3N 148.5W
Max sustained: 130 MPH
Moving: W at 16 MPH
Min pressure: 947 MB

A strong high pressure center far to the north of the Hawaiian Islands will continue to produce breezy trade winds over the state through much of the week. Trade winds will trend higher as Hurricane Hector tracks south of the state starting later tonight through Thursday. Large scale subsidence aloft will continue to keep a strong trade wind inversion around 5000 to 6000 feet elevation, capping cloud heights and limiting shower activity. Scattered showers will remain limited to windward and mountain areas with better chances for showers in the overnight hours.Hurricane Hector Distances 0800 Hours 2018

Tonight through Thursday, the current forecast for Hurricane Hector keeps the center of the storm passing south of the Hawaiian Islands. Weather impacts for each island remains highly dependent on Hector’s track and intensity. Trade wind speeds will trend higher as pressure gradients increase with Hector’s passage to the south. An area of deep tropical moisture associated with Hector will produce an increase in rain showers over eastern slopes of the Big Island, with the highest precipitation amounts forecast over southeast sections of the Puna and Kau Districts as surface winds become more southeasterly on Wednesday. Other areas of the state may see little change in rainfall from current levels. Please continue to closely monitor this strong hurricane as it moves closer to the state.

Friday through Sunday, Hector will have exited the region. High pressure north of the state will provide for a typical trade wind weather pattern through the weekend. Clouds and passing showers will tend to favor windward and mountain areas with most leeward areas remaining dry through the weekend.

Volcanic emissions for the Kilauea volcano area will remain in a trade wind flow pattern through Wednesday morning with any emissions drifting southwest into the Kau district of the Big Island. By Wednesday evening wind directions will likely shift towards the southeast as Hurricane Hector passes by to the south of the Big Island. These southeasterly winds will tend to push any emissions towards the northwest up through Hilo and along the northern slopes of the Big Island through Thursday. Easterly trade winds are expected to return on Friday with any volcanic emissions drifting back towards the southwest through the weekend.

NWS Central Pacific Hurricane Center Honolulu HI 200 AM HST Tue Aug 7 2018

For the central North Pacific…between 140W and 180W: The Central Pacific Hurricane Center is issuing advisories on Hurricane Hector, located about 585 miles east-southeast of Hilo, Hawaii.

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Mon Aug 06 2018

Hector remains a powerful category 4 hurricane this evening, but the satellite presentation has degraded slightly since the previous advisory, likely due to the storm feeling some of the effects of the very dry mid-level air on the periphery of the system. Hector continues to display a well defined 10 nautical mile wide eye, surrounded by a ring of -65 to -75 degree Celsius cloud tops. The latest subjective Dvorak current intensity estimates from PHFO, SAB and JTWC came in at 6.5 (127 knots), while the latest estimate using the Advanced Dvorak technique from UW-CIMSS yielded 6.6 (130 knots). In addition, the Air Force Reserves 53rd Weather Reconnaissance Squadron measured a surface wind of 126 knots in the northwest eye wall around 0730Z. Taking all this data into account, the initial intensity has been lowered to 125 knots. Hector continues to track just north of due west, with an initial motion set at 280/14 knots.

The latest model guidance remains tightly clustered and brings Hector just north of due west tonight and Tuesday. A building subtropical ridge to the north of the Hawaiian Islands should then steer Hector due westward Tuesday night through Thursday night. The system should begin to bend back toward the west-northwest or northwest Friday through Saturday as it rounds the southwest periphery of the subtropical ridge and begins to be influenced by an upper level trough setting up between 170W and the International Date Line. The new official forecast track has been nudged slightly southward and is roughly in between the previous official forecast and the latest model consensus. The forecast track brings the center of Hector roughly around 165 miles south of the Big Island as a major hurricane on Wednesday, and given the proximity of the storm to the island, the Tropical Storm Watch remains in effect.

Hector will remain in a favorable low shear environment through Friday, before west-southwesterly shear increases late Friday or Saturday. There are a couple factors that should lead to gradual weakening over the next few days however. The hurricane will be traveling over marginal sea surface temperatures around 27C through Wednesday night, before the SSTs increase slightly to around 28C to the south and southwest of the Hawaiian Islands Thursday through Saturday. Additionally and likely more importantly, very dry mid-level air will surround the storm through the forecast period, and this is expected to lead to gradual weakening of the system over the next couple days. The intensity of Hector is then expected to level off Thursday through Friday as it encounters the higher SSTs. Some weakening should then ensue by Saturday as Hector begins to feel increasing west-southwesterly shear as it approaches the upper trough between 170W and the Date Line. The intensity forecast has been adjusted slightly lower than the previous forecast through 36 hours, then slightly higher between 48 and 120 hours, which is in line with the latest trends of the statistical and dynamical models, but with more weight given to the dynamical models which have been performing better over the past several days.Hurricane Hector Position August 8 2018

FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0900Z 15.8N 146.3W  125 KT 145 MPH - Category 4 (SE Hilo, Kawaii)
 12H  07/1800Z 16.1N 148.6W  120 KT 140 MPH - Category 4 (SE Hilo, Kawaii)
 24H  08/0600Z 16.3N 151.5W  110 KT 125 MPH - Category 3 (SE Hilo, Kawaii)
 36H  08/1800Z 16.4N 154.5W  105 KT 120 MPH - Category 3 (SW Hilo, Kawaii)
 48H  09/0600Z 16.8N 163.8W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 72H  10/0600Z 16.8N 163.8W  100 KT 115 MPH - Category 3 (SW Hilo, Kawaii)
 96H  11/0600Z 18.0N 169.5W  100 KT 115 MPH - Category 3 (N Johnson Atoll)
120H  12/0600Z 19.5N 173.5W   90 KT 105 MPH - Category 1 ()SW Hilo, Kawaii)

NWS Central Pacific Hurricane Center Honolulu Hi 200 PM HST Mon Aug 06 2018

At 200 PM HST (0000 UTC), the center of Hurricane Hector was located near latitude 15.5 North, longitude 143.9 West.

Hector is moving toward the west near 16 mph (26 km/h). This general motion is expected to continue for the next couple of days. On the forecast track, Hector is expected to pass roughly 150 miles south of the Big Island of Hawaii on Wednesday. Maximum sustained winds are near 155 mph (250 km/h) with higher gusts. Hector is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next 48 hours, though Hector is expected to remain a major hurricane. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km). The estimated minimum central pressure is 936 mb (27.64 inches).

SUMMARY OF WATCHES AND WARNINGS IN EFFECT: * A Tropical Storm Watch is in effect for… * Hawaii County A Tropical Storm Watch means that tropical storm conditions are possible within the watch area within 48 hours. Interests elsewhere in the Hawaiian Islands should monitor the progress of Hector. For storm information specific to your area, please monitor products issued by the National Weather Service office in Honolulu, Hawaii.

SURF: Swells generated by Hector are expected to reach southeast and east facing shores of the Big Island and eastern Maui during the next day, likely becoming large by late Tuesday and Wednesday.

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Mon Aug 06 2018

The satellite presentation of Hurricane Hector  continues to be very impressive. Hurricane Hunter aircraft from the US Air Force 53rd Weather Reconnaissance Squadron embarked on their first mission into Hector and found the system to be stronger than anticipated, with surface winds from the SFMR up to 137 kt and only slightly weaker winds based on flight level data. Fixes from HFO, SAB, and JTWC all came in at 6.5/127 kt, and CIMSS ADT yielded 137 kt. Given these data, the initial intensity has been raised to 135 kt, making Hector a strong category four hurricane. Slight adjustments to the wind radii were incorporated based on input from the aircraft. Unfortunately, the Hurricane Hunter mission had to cut short due to mechanical concerns, and there will not be additional data for the afternoon. The next mission into Hector will be this evening.

The initial motion of Hector is slightly north of due west (280 degrees) at 14 kt. The track guidance continues to be very tightly clustered, showing Hector on a similar track during the next 36 hours. The hurricane is expected to take a turn toward due west (270 degrees) on Wednesday and Thursday as ridging to the north of the system strengthens. This is expected to take Hector just south of the Hawaiian Islands. A gradual turn toward the west-northwest is expected on days four and five as the mid to upper level ridge north of Hector weakens.

Although the intensity forecast remains challenging, Hector is expected to remain a major hurricane as it slowly weakens during the next couple of days. Hector will remain in a low vertical wind shear environment to the south of a strong ridge aloft for the next several days. However, sea surface temperature will lower slightly, and the system will be surrounded by dry mid level air, which should lead to gradual weakening. So far, this has not had much of an effect on Hector, and the intensity forecast has lower confidence. The forecast rate of weakening is line with the dynamical models, keeping Hector slightly stronger than SHIPS during the next 72 hours. Thereafter, little change in intensity is expected as sea surface temperatures increase.

While the official forecast track continues to lie to the south of the Hawaiian Islands, only a slight deviation to the north of the forecast track would significantly increase potential impacts to the portions of the state. This necessitates a Hurricane Watch for Hawaii County.

FORECAST POSITIONS AND MAX WINDS
 
INIT  06/2100Z 15.2N 143.1W  135 KT 155 MPH - Category 4 (SE of Hilo, Hawaii)
 12H  07/0600Z 15.6N 145.2W  130 KT 150 MPH - Category 4 (SE of Hilo, Hawaii)
 24H  07/1800Z 16.0N 148.1W  120 KT 140 MPH - Category 4 (SE of Hilo, Hawaii)
 36H  08/0600Z 16.3N 151.0W  110 KT 125 MPH - Category 3 (SE of Hilo, Hawaii)
 48H  08/1800Z 16.5N 154.1W  105 KT 120 MPH - Category 3 (S of Hilo, Hawaii)
 72H  09/1800Z 16.7N 160.5W   95 KT 110 MPH - Category 2 (SW of Hilo, Hawaii)
 96H  10/1800Z 17.1N 166.4W   90 KT 105 MPH - Category 2 (NE of Johnson Atoll)
120H  11/1800Z 18.0N 171.2W   90 KT 105 MPH - Category 2 (N of Johnson Atoll)

Central Pacific Hurricane Center Honolulu HI 500 AM HST Mon Aug 06 2018

The satellite presentation of Hurricane Hector  has improved overnight, with a well defined 10 to 15 nautical mile wide eye surrounded by a large ring of -70 to -80 Celsius cloud tops. The latest subjective Dvorak current intensity estimates from SAB and JTWC came in at 6.5 (127 knots), while PHFO came in at 6.0 (115 knots).

The latest estimate using the Advanced Dvorak technique from UW-CIMSS yielded 6.8 (135 knots). Given that Hector’s satellite presentation has improved since the previous advisory, we have elected to raise the initial intensity to 125 knots which correlates well with a blend of the available intensity estimates. Hector has continued to track westward at about the same speed as the previous advisory, so the initial motion remains 280/13 knots.

The latest model guidance remains tightly clustered and brings Hector just north of due west over the next 36 to 48 hours due to a weakness in the subtropical ridge to the northeast of the Hawaiian Islands. Beyond 48 hours, the subtropical ridge is forecast to build to the north of the Hawaiian Island chain, and this should steer Hector due westward from 48 to 96 hours, before bending back to the west-northwest beyond 96 hours as a digging upper level trough between 170W and the International Date Line begins to erode the western portion of the subtropical ridge. The new official forecast track is very close to the model consensus and nearly identical to the previous official track forecast.

Hector will remain in a favorable low shear environment through the forecast period, but there are some factors that should lead to gradual weakening over the next few days. The hurricane will be traveling over marginal sea surface temperatures around 27C through Wednesday, before the SSTs increase slightly to around 28C to the south of the Hawaiian Islands Wednesday night through Friday. Additionally and likely more importantly, very dry mid-level air will begin to surround the storm beginning later today or tonight, and this is expected to lead to a slow and gradual weakening of the system through Wednesday night. The intensity of Hector is then expected to level off Wednesday night through Friday as it encounters the higher SSTs, with some indication from the HWRF that re-intensification could occur. The intensity forecast has been adjusted slightly higher than the previous forecast due to both the statistical and dynamical models trending higher and coming into somewhat better agreement. Given the recent better performance of the dynamical guidance in comparison to the statistical guidance, more weight was placed on the dynamical models when preparing the intensity forecast for this advisory package as well.

While the official forecast track continues to lie to the south of the Hawaiian islands, only a slight deviation to the north of the forecast track would significantly increase potential impacts to the state of Hawaii. Now is a good time for everyone in the Hawaiian Islands to ensure that they have their hurricane plan in place.

Hurricane Hector Location 0800 Hours August 6 2018
Hurricane Hector Location 0800 Hours August 6 2018
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/1500Z 15.0N 141.9W  125 KT 145 MPH - Category 4 (SE of Hilo, Hawaii)
 12H  07/0000Z 15.4N 144.0W  120 KT 140 MPH - Category 4 (SE of Hilo, Hawaii)
 24H  07/1200Z 15.9N 146.9W  115 KT 130 MPH - Category 4 (SE of Hilo, Hawaii)
 36H  08/0000Z 16.2N 149.9W  110 KT 125 MPH - Category 3 (SE of Hilo, Hawaii)
 48H  08/1200Z 16.5N 153.0W  105 KT 120 MPH - Category 3 (SE of Hilo, Hawaii)
 72H  09/1200Z 16.6N 159.3W   95 KT 110 MPH - Category 2 (SW of Hilo, Hawaii)
 96H  10/1200Z 17.0N 165.4W   90 KT 105 MPH - Category 2 (SW of Hilo, Hawaii)
120H  11/1200Z 17.7N 170.6W   90 KT 105 MPH - Category 2 (SW of Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 PM PDT Sun Aug 05 2018

This special advisory is to update the initial and forecast intensities for Hector . Satellite data indicate that the hurricane has continued to strengthen during the past 6 h, and the initial intensity has increased to at least 120 kt. Based on this, the intensities for the first 36 h of the forecast have been increased. There are no changes to the forecast track, the wind radii, or the intensities from 48-120 h.

The NOAA G-IV aircraft is releasing dropsondes as it circumnavigates Hector during its flight to Hawaii to support forecast operations over the next few days. Data from these dropsondes should be incorporated into this evening’s 0000 UTC dynamical models.

While the official forecast track continues to lie south of the Hawaiian Islands, only a slight deviation to the north of the forecast track would significantly increase potential impacts on the Hawaiian Islands. It is a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT  06/0000Z 14.5N 138.6W  120 KT 140 MPH - Category 4 (SE of Hilo, Hawaii)
 12H  06/0600Z 14.7N 139.8W  120 KT 140 MPH - Category 4 (SE of Hilo, Hawaii)
 24H  06/1800Z 15.3N 142.4W  115 KT 130 MPH - Category 4 (SE of Hilo, Hawaii)
 36H  07/0600Z 15.9N 145.3W  105 KT 120 MPH - Category 3 (SE of Hilo, Hawaii)
 48H  07/1800Z 16.4N 148.4W   95 KT 110 MPH - Category 2 (SE of Hilo, Hawaii)
 72H  08/1800Z 16.7N 154.5W   90 KT 105 MPH - Category 2 (S of Hilo, Hawaii)
 96H  09/1800Z 17.0N 160.3W   85 KT 100 MPH - Category 2 (SW of Hilo, Hawaii)
120H  10/1800Z 17.7N 166.0W   80 KT  90 MPH - Category 1 (SW of Hilo, Hawaii)

NWS National Hurricane Center Miami FL 800 AM PDT Sun Aug 05 2018

Hector continues to maintain a 10-15 n mi wide eye surrounded by a ring of -60 to -70 degrees Celsius cloud tops. The eye has become slightly less distinct this morning and recent microwave data suggest that an eyewall replacement cycle could be occurring. A 1111 UTC AMSR2 microwave overpass shows a double eyewall structure with the inner eyewall open to the southwest. The various subjective and objective satellite estimates are between 102-110 kt, and the initial wind speed is kept near the upper-end of these estimates for now.

The hurricane is moving westward or 275/10 kt. A westward to west-northwestward motion is expected over the next day or so as Hector is steered by a deep-layer ridge to its north. The ridge is forecast to strengthen north of the Hawaiian Islands by mid-week which should cause the hurricane to move on a general westward track throughout most of the remainder of the forecast period. While all of the dynamical models are in agreement on the overall scenario there is a fairly typical amount of cross-track spread with the ECMWF along the southern edge of the guidance envelope and the HMON and GFS along the northern side. The updated NHC track forecast is close to the latest consensus aids, and little overall change to the previous forecast was required.

Hector is forecast to remain over warm SSTs and within a low shear environment for the next couple of days, and it is possible for some fluctuations in intensity to occur as the result of eyewall replacements. By 48 h, the hurricane is predicted to encounter some drier mid-level air which is forecast to cause gradual weakening after that time. The latest NHC intensity forecast is a little above the statistical guidance, closest to the HCCA and FSSE intensity models.

While the official forecast track continues to lie south of the Hawaiian Islands, it is too soon to determine what kind of impacts might occur in the state, since track errors can be large at long time ranges. This remains a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 14.4N 136.9W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 12H  06/0000Z 14.6N 138.6W  105 KT 120 MPH Category 3 (SE of Hilo Hawaii)
 24H  06/1200Z 15.1N 141.2W  105 KT 120 MPH Category 3 (SE of Hilo Hawaii)
 36H  07/0000Z 15.7N 144.1W  100 KT 115 MPH Category 3 (SE of Hilo Hawaii)
 48H  07/1200Z 16.3N 147.1W   95 KT 110 MPH Category 2 (SE of Hilo Hawaii)
 72H  08/1200Z 16.8N 153.2W   90 KT 105 MPH Category 2 (SE of Hilo Hawaii)
 96H  09/1200Z 17.2N 158.8W   90 KT 105 MPH Category 2 (SW of Hilo Hawaii)
120H  10/1200Z 17.8N 164.2W   85 KT 100 MPH Category 2 (SW of Hilo Hawaii)

NWS National Hurricane Center Miami FL 500 AM PDT Sun Aug 5 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Hurricane Hector, located well east-southeast of the Big Island of Hawaii, and on Tropical Depression Eleven-E, located a couple of hundred miles south of Puerto Angel, Mexico.

NWS National Hurricane Center Miami FL 200 PM PDT Sat Aug 04 2018

Satellite images indicate that the small eye of Hector has grown larger over the past several hours, with a rapid axisymmetrization of the eyewall convection. It seems that the eyewall cycle has completed itself rather quickly, with one distinct eyewall now noted. Dvorak estimates are on the rise again, and the latest initial wind speed is set to 110 kt, which is a blend of the latest satellite estimates. While there has been no scatterometer data during the past day or so, the microwave data show that Hector has grown in size, so the initial wind radii have been expanded, although are smaller than the latest CIMSS and CSU/CIRA estimates.

Hector appears to be in the process of becoming an annular hurricane, with little outer banding and a fairly symmetric inner core. This subset of hurricanes is known to occur under moderate SSTs below 28.5C, with light easterly shear and no trough interactions. The bottom line for the intensity forecast is that these conditions are likely to persist near Hector for the next few days, and intensity guidance is known to have a low bias for annular hurricanes. The new intensity forecast is raised from the previous one, and is near or above the guidance, showing only a slow demise over the central Pacific as environmental conditions gradually deteriorate.

Hector continues a westward motion of 270/10 kt. A large subtropical ridge to the north should steer the hurricane generally westward throughout the forecast period, with Hector gradually gaining some latitude on Sunday and beyond due to a weakness in the ridge. By 96 hours, most of the guidance shows a more due-westward motion south of the Hawaiian Islands. The only significant change from the past advisory is a slightly slower forward speed for the first couple of days.

While the official forecast track continues to lie south of the Hawaiian Islands, it is too soon to determine what kind of impacts might occur in the state, since track errors can be large at long range. This remains a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place.

Hurricane Hector Position August 7 2018
Hurricane Hector Position August 7 2018
FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 14.2N 133.7W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 12H  05/0600Z 14.3N 135.2W  115 KT 130 MPH Category 3 (SE of Hilo Hawaii)
 24H  05/1800Z 14.5N 137.4W  115 KT 130 MPH Category 4 (SE of Hilo Hawaii)
 36H  06/0600Z 14.8N 139.9W  115 KT 130 MPH Category 4 (SE of Hilo Hawaii)
 48H  06/1800Z 15.3N 142.7W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 72H  07/1800Z 16.3N 148.7W  100 KT 115 MPH Category 3 (SE of Hilo Hawaii)
 96H  08/1800Z 16.7N 154.5W   90 KT 105 MPH Category 2 (S of Hilo Hawaii)
120H  09/1800Z 17.0N 160.0W   85 KT 100 MPH Category 2 (SW of Hilo Hawaii)

NWS National Hurricane Center Miami FL 1100 AM PDT Sat Aug 4 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Hurricane Hector , located over the far southwestern part of the basin.

Hurricane Hector centered near 14.2N 132.7W at 04/1500 UTC or 1390 nm WSW of the southern tip of the Baja California Peninsula moving W at 10 kt. Estimated minimum central pressure is 962 mb. Maximum sustained wind speed is 105 kt with gusts to 115 kt. Numerous moderate to strong convection is observed within 120 nm of center.

NWS National Hurricane Center Miami FL 800 AM PDT Sat Aug 04 2018

There have been some subtle changes in Hector during the past several hours with satellite imagery indicating a slight disruption of the eyewall convective pattern. This appears to be due to a slowly evolving eyewall cycle, which can only be readily seen by high-resolution microwave data such as AMSR2, due to Hector’s small size. Intensity estimates remain virtually the same, so the wind speed is held at 105 kt.

Due the eyewall cycle, future intensity changes are harder to predict. Since Hector is forecast to remain in a favorable large-scale environment, albeit with marginal SSTs, little overall change in strength is indicated during the next couple of days. Hector’s small size could also make it prone to short-term fluctuations in intensity, up or down, like the one observed yesterday. In about 3 days, Hector is forecast to move over somewhat cooler SSTs and into a drier environment, so gradual weakening is shown. Little change was made to the previous NHC wind speed prediction, near or just above the model consensus.

Hector is locked into a westward motion of 270/10 kt. A large subtropical ridge to the north should steer the hurricane generally westward throughout the forecast period, with Hector gradually gaining some latitude on Sunday and beyond due to a weakness in the ridge. Overall the model guidance is in much better agreement than yesterday, and only cosmetic changes were made to previous track forecast.

There is the potential for Hector to affect portions of the Hawaiian Islands by the middle of next week, but it is too soon to specify the magnitude of any impacts or where they could occur. This is a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT  04/1500Z 14.2N 132.7W  105 KT 120 MPH  Category 3 (SE of Hilo Hawaii)
 12H  05/0000Z 14.2N 134.2W  105 KT 120 MPH  Category 3 (SE of Hilo Hawaii)
 24H  05/1200Z 14.4N 136.4W  110 KT 125 MPH  Category 3 (SE of Hilo Hawaii)
 36H  06/0000Z 14.7N 138.8W  110 KT 125 MPH  Category 3 (SE of Hilo Hawaii)
 48H  06/1200Z 15.1N 141.4W  105 KT 120 MPH  Category 3 (SE of Hilo Hawaii)
 72H  07/1200Z 16.1N 147.2W   95 KT 110 MPH  Category 2 (SE of Hilo Hawaii)
 96H  08/1200Z 16.6N 153.1W   90 KT 105 MPH  Category 2 (SE of Hilo Hawaii)
120H  09/1200Z 17.0N 158.5W   85 KT 100 MPH  Category 2 (SW of Hilo Hawaii)

NWS National Hurricane Center Miami FL 800 PM Fri Aug 03 2018 

Hurricane Hector centered near 14.1N 129.8W at 03/2100 UTC or  1490 nm E of Hilo Hawaii moving W at 10 kt. Estimated minimum  central pressure is 975 mb. Maximum sustained wind speed is 90  kt with gusts to 110 kt. Numerous moderate to strong convection  is observed within 90 nm of center. Scattered moderate isolated  strong convection is observed within 45 nm either side of a line  from 15N125W to 10N132W.

NWS National Hurricane Center Miami FL EP102018 800 PM PDT Fri Aug 03 2018 Hector has continued to quickly strengthen since the last advisory, with the eye becoming more distinct and the cloud tops in the eyewall cooling to near -80C. Satellite intensity estimates from TAFB and SAB were 102 kt near 00Z, and given the increasing organization since that time the initial intensity is increased to 105 kt.

The initial motion is now 275/10. There is again little change to the track forecast philosophy, as a large subtropical ridge to the north of the hurricane should steer Hector generally westward during the forecast period. Due to a weakness in the ridge, the hurricane is forecast to gain some latitude from 36-96 h. While the guidance agrees with this scenario, there is a significant amount of spread between the GFS and NAVGEM on the north side of the guidance envelope and the UKMET and ECMWF on the south side. The consensus models are in the center of the envelope, and the new forecast is close to these in best agreement with the HCCA corrected consensus. The new forecast is little changed from the previous track.

Recent satellite microwave data show that Hector is developing an outer eyewall, which suggests the hurricane should undergo an eyewall replacement cycle during the next day or so. This makes it a little unclear how long the current intensification will last. The intensity forecast will show a little more strengthening during the next 12 hr followed by little change in strength through 36 h. The HWRF, HMON, and COAMPS-TC models show a little more intensification at 48-60 h, and the official forecast follows suit. After that time, while Hector should remain in a light-shear, warm-water environment, entrainment of drier air should lead to a gradual weakening of the cyclone. Overall, the new intensity forecast lies near the upper edge of the intensity guidance.

There is the potential for Hector to bring some impacts to portions of the Hawaiian Islands by the middle of next week, but it is too soon to specify the magnitude of the impacts or where they could occur. This is a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place. For additional information on any potential local impacts from Hector in Hawaii, please refer to products issued by the NWS Weather Forecast Office in Honolulu at

FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 14.2N 130.9W  105 KT 120 MPH Category 3 (SE of Hilo Hawaii)
 12H  04/1200Z 14.3N 132.4W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 24H  05/0000Z 14.2N 134.5W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 36H  05/1200Z 14.2N 136.6W  110 KT 125 MPH Category 3 (SE of Hilo Hawaii)
 48H  06/0000Z 14.5N 139.1W  115 KT 130 MPH Category 4 (SE of Hilo Hawaii)
 72H  07/0000Z 15.5N 144.5W  105 KT 120 MPH Category 3 (SE of Hilo Hawaii)
 96H  08/0000Z 16.5N 150.5W   90 KT 105 MPH Category 2 (SE of Hilo Hawaii)
120H  09/0000Z 16.5N 156.0W   80 KT  90 MPH Category 1 (SW of Ocean View, Hawaii)

NWS National Hurricane Center Miami FL 500 PM PDT Fri Aug 3 2018

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

The National Hurricane Center is issuing advisories on Hurricane Hector, located well southwest of Baja California Sur.

Hurricane Hector centered near 14.1N 129.8W at 03/2100 UTC or 1490 nm E of Hilo Hawaii moving W at 10 kt. Estimated minimum central pressure is 975 mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt. Numerous moderate to strong convection is observed within 90 nm of center. Scattered moderate isolated strong convection is observed within 45 nm either side of a line from 15N125W to 10N132W. Refer to the latest NHC forecast/ advisory under AWIPS/WMO headers MIATCPEP5/WTPZ35 KNHC for additional details.

A disorganized surface low has developed along the monsoon trough near 10N100W and is accompanied by scattered moderate isolated strong convection within 120 nm either side of a line from 08N96W to 11N106W. This low is forecast to move NW to an estimated position near 12N102W on Sat and near 13N103W on Sun. The low is expected to continue NW across the far offshore waters between 100W and 117W through the middle of next week. Although track and intensity are uncertain, mariners should expect at least increasing southerly winds followed by strong to near gale force easterly winds, and building seas. This low has a medium chance of developing into a tropical cyclone during the next 48 hours. Refer to the East Pacific Tropical Weather Outlook under WMO/AWIPS header ABPZ20 KNHC/MIATWOEP for additional information. A surface low has developed along the monsoon trough near 13N113.5W accompanied by scattered moderate isolated strong convection within 120 nm either side of a line from 15N115W to 11N116W with the convection organizing into bands.

This low has a medium chance of developing into a tropical cyclone during the next 48 hours. Refer to the East Pacific Tropical Weather Outlook under WMO/AWIPS header ABPZ20 KNHC/MIATWOEP for additional information.

NWS National Hurricane Center Miami FL 1100 AM PDT Fri Aug 3 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Hurricane Hector, located well southwest of Baja California Sur.

Hurricane Hector centered near 14.1N 128.8W at 03/1500 UTC or  1550 nm E of Hilo Hawaii moving W at 10 kt. Estimated minimum  central pressure is 983 mb. Maximum sustained wind speed is 80  kt with gusts to 100 kt. Numerous moderate to strong convection  is observed within 90 nm of center. Scattered moderate isolated  strong convection is observed within 45 nm either side of a line  from 14N125W to 10N131W.

NWS National Hurricane Center Miami FL 800 AM PDT Fri Aug 03 2018

The satellite presentation of Hector has degraded over the past several hours, with only occasional hints of an eye in the latest imagery. More notably, an AMSR2 microwave pass at 0945Z shows a secondary eyewall structure beginning, with a ring of convection noted at about a 30 n mi radius. All these data indicate that Hector has weakened, so the initial wind speed is conservatively reduced to 80 kt, near or just above the latest Dvorak estimates.

The current northeasterly shear is forecast to abate by the numerical models during the next 12 hours, which would normally lead to a restrengthening of Hector. However, the secondary eyewall formation throws a wrinkle into the forecast, since that process usually takes longer than that amount of time. As a compromise, gradual intensification is shown starting tomorrow, with a small uptick on Sunday as Hector reaches warmer waters in a light-shear environment. The HWRF and HMON still show Hector becoming a major hurricane, so it is too soon to abandon that forecast. The new forecast is a blend of the latest corrected-consensus guidance and the previous forecast, resulting in about a 10-kt reduction from the last NHC prediction. Slow weakening is shown at the end of the forecast due to cooler SSTs and potential entrainment of drier mid-level air.Hurricane Hector August 6 2018

FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 14.1N 128.8W   80 KT  90 MPH - Category 1 (SE of Hilo Hawaii)
 12H  04/0000Z 14.2N 130.4W   80 KT  90 MPH - Category 1 (SE of Hilo Hawaii)
 24H  04/1200Z 14.2N 132.4W   85 KT 100 MPH - Category 2 (SE of Hilo Hawaii)
 36H  05/0000Z 14.1N 134.5W   90 KT 105 MPH - Category 2 (SE of Hilo Hawaii)
 48H  05/1200Z 14.2N 136.6W  100 KT 115 MPH - Category 3 (SE of Hilo Hawaii)
 72H  06/1200Z 15.1N 141.4W  100 KT 115 MPH - Category 3 (SE of Hilo Hawaii)
 96H  07/1200Z 16.3N 146.7W   90 KT 105 MPH - Category 2 (SE of Hilo Hawaii)
120H  08/1200Z 17.0N 152.0W   85 KT 100 MPH - Category 2 (SE of Hilo Hawaii)

The initial motion remains 270/10 kt. A large subtropical ridge should steer the hurricane westward for the next couple of days, then a weakness in the ridge develops, which should cause a more west-northwestward track. The model guidance suite is a little slower than yesterday, about 1 or 2 kt overall. While that doesn’t sound like much, over the course of a forecast that could change the final cyclone position by a few degrees, so it is meaningful. In this particular case, a slower solution turns Hector to the west-northwest earlier in the forecast, since the hurricane feels the developing weakness to the north-northeast sooner. The new NHC track forecast follows the trend of the model consensus and is adjusted slightly to the north.

NWS National Hurricane Center Miami FL 500 AM PDT Fri Aug 3 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Hurricane Hector, located well southwest of Baja California Sur.

Hurricane Hector centered near 14.0N 127.8W at 0900 UTC moving W at 10 kt. Estimated minimum central pressure is 975 mb. Maximum sustained winds are 90 kt with gusts to 110 kt. Numerous moderate to strong convection is within 90 nm of the center. Scattered moderate isolated strong convection is observed elsewhere within 120 nm of the center.

NWS National Hurricane Center Miami FL 0405 UTC Fri Aug 3 2018 

Tropical Weather Discussion for the eastern Pacific Ocean from  the Equator to 32N, east of 140W. The following information is  based on satellite imagery, weather observations, radar, and  meteorological analysis.

Hurricane Hector centered near 14.1N 126.9W at 0300 UTC moving W at 11 kt. Estimated minimum central pressure is 973 mb. Maximum  sustained winds are 95 kt with gusts to 115 kt. Numerous  moderate to strong convection is within 90 nm of the center.  Scattered moderate isolated strong convection is observed  elsewhere within 120 nm of center, and within 90 nm either side  of a line from 14N125W to 12N123W. Refer to the latest NHC  forecast/advisory under AWIPS/WMO headers MIATCPEP5/WTPZ35 KNHC  for additional details.

NWS National Hurricane Center Miami FL 200 PM PDT Thu Aug 02 2018

Hector  is a small but powerful hurricane this afternoon. Visible GOES-15 data show that it has a 10 n mi wide eye, surrounded by a increasingly symmetric area of deep convection. The latest satellite estimates at 18 UTC were between 90 kt and 95 kt, and since the presentation has continued to improve during the past few hours, the initial wind speed is set to 95 kt.

Hector has intensified an impressive 50 kt over the past 24 hours- remarkable since the environment did not seem particularly favorable even 12 hours ago. What is perplexing about this forecast is that, despite all of the global models showing a more conducive environment during the next day or two, none of the regional hurricane models show intensification, and in fact they all show weakening. This would be a dramatic change, which seems pretty unlikely given the current state of things. It makes the most sense to show continuing strengthening, albeit at a reduced rate since the SSTs do moderate, in line with the SHIPS & LGEM models. The new forecast has a peak intensity at 72 hours when SSTs are the warmest with the lowest environmental shear. After that time, water temperatures and mid-level humidites should gradually decrease, which will probably promote some weakening. Obviously this is a low confidence forecast, and I wouldn’t be surprised if it had to be raised in the short term later tonight.Hurricane Hector 1400 Hours August 2 2018

Hector continues on course, moving westward at 12 kt. The track forecast for the next 3 days is of high confidence, since the guidance is in good agreement and a large subtropical ridge is providing a well-defined steering current. Complications arise in the long range due to the potential interaction of Hector with a mid-level trough in the Central Pacific. The latest models show Hector moving into a weakness in the ridge associated with the trough, causing a more west-northwestward motion earlier in the forecast. This is a fairly subtle change but has led to most of the guidance trending to the north. The official forecast is shifted in that direction, but remains on the southwest side of the guidance envelope, close to the corrected-consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 14.1N 125.8W   95 KT 110 MPH - Category 2 (SE of Hilo Hawaii)
 12H  03/0600Z 14.0N 127.6W  100 KT 115 MPH - Category 3 (SE of Hilo Hawaii)
 24H  03/1800Z 13.9N 129.8W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)
 36H  04/0600Z 13.9N 132.0W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)
 48H  04/1800Z 13.8N 134.3W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)
 72H  05/1800Z 13.6N 139.0W  115 KT 130 MPH - Category 4 (SE of Hilo Hawaii)
 96H  06/1800Z 14.5N 144.0W  110 KT 125 MPH - Category 3 (SE of Hilo Hawaii)
120H  07/1800Z 15.5N 149.0W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)

NWS National Hurricane Center Miami FL 1100 AM PDT Thu Aug 02 2018

Tropical Storm Hector centered near 14.2N 124.6W at 02/1500 UTC  or 990 nm WSW of the southern tip of the Baja California  Peninsula moving W at 12 kt. Estimated minimum central pressure  is 987 mb.

Maximum sustained wind speed is 75 kt with gusts to  85 kt. Numerous moderate to strong convection is observed within  90 nm of center. Scattered moderate isolated strong convection is  observed elsewhere within 210 nm SW and 120 nm NW semicircles of  center.

NWS National Hurricane Center Miami FL 800 AM PDT Thu Aug 02 2018

Tropical Storm Hector centered near 14.3N 123.4W at 02/0900 UTC or 930 nm WSW of The Southern Tip Of Baja California moving WNW at 10 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 60 kt with gusts to 70 kt. Northeasterly shear is impacting the storm currently. Numerous moderate to
scattered strong convection is noted within 45 nm in the northeast and 150 nm in the southwest semicircles of Hector.

Well, so much for the shear. Satellite images indicate that Hector is rapidly intensifying and has recently formed a small eye. The initial wind speed is set to 75 kt, based on the TAFB Dvorak estimate. While there still could be some shear over the next day or so, it seems apparent now that the highest shear should stay north of the tropical cyclone, leaving Hector in a pocket of lighter winds. The main inhibiting factor is expected to be more marginal SSTs, with temperatures below 27C in the path of the hurricane. The official forecast assumes the current intensification trend will last for another 12 hours or so, then levels off due to the more marginal waters, similar to the latest SHIPS/LGEM forecasts. It is worth noting that the regional hurricane models show an unrealistic solution of significant weakening in the short term, and have been disregarded. In the longer range, the upper-level environment and water temperatures are more than sufficient to support a major hurricane, and the new forecast reflects these conditions.

Hector has turned westward and accelerated, now moving 12 kt. A large subtropical ridge is forecast to build westward over the next several days, keeping the cyclone on this general course into the Central Pacific. The ridge could weaken somewhat by day 5, causing a more west-northwestward motion early next week. Little change was made to the previous official track forecast, although it is a shade faster at the end of the period.

FORECAST POSITIONS AND MAX WINDS
Hurricane Hector Position SE Hilo Hawaii August 5 2018
Hurricane Hector Position SE Hilo Hawaii August 5 2018
INIT  02/1500Z 14.2N 124.6W   75 KT  85 MPH
 12H  03/0000Z 14.3N 126.5W   90 KT 105 MPH
 24H  03/1200Z 14.3N 128.7W   95 KT 110 MPH
 36H  04/0000Z 14.2N 131.0W   95 KT 110 MPH
 48H  04/1200Z 14.0N 133.3W   95 KT 110 MPH
 72H  05/1200Z 13.6N 138.1W  100 KT 115 MPH - Category 2 (SE of Hilo Hawaii)
 96H  06/1200Z 13.8N 143.1W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)
120H  07/1200Z 14.5N 148.0W  105 KT 120 MPH - Category 3 (SE of Hilo Hawaii)

NWS National Hurricane Center Miami FL 1100 PM PDT Wed Aug 1 2018

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Tropical Storm Hector, located well southwest of the southern tip of the Baja California Peninsula.

Tropical Storm Hector centered near 13.8N 121.2W at 01/2100 UTC  or 970 sm SW of the southern tip of the Baja California  Peninsula moving W at 10 kt. Estimated minimum central pressure  is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to  55 kt. Scattered strong convection is observed within 180 nm
over the SE and within 150 nm over the NW semicircle of the  center.

1. An area of disturbed weather is located several hundred miles south of Manzanillo, Mexico. Environmental conditions appear conducive for gradual development of this system during the next few days as it moves generally westward across the tropical eastern Pacific. By early next week, close proximity to another low pressure system could limit the potential for further development of this disturbance. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…30 percent.

2. An area of low pressure is forecast to form several hundred miles south or southwest of the southern coast of Mexico late this week. Environmental conditions are expected to be conducive for gradual development of this system over the weekend, and a tropical depression could form early next week while it moves west-northwestward off the coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium...60 percent.

NWS National Hurricane Center Miami FL 800 PM PDT Wed Aug 01 2018

Visible satellite imagery continues to show an increase in banding in association with Hector, and the last several images suggest that a small CDO may be developing. Recent microwave data, however, has not shown any significant improvement of the inner core. The latest Dvorak satellite estimates are 45 kt from SAB and 55 kt from TAFB, while AMSU and objective UW/CIMSS Dvorak estimates are in between. As a result, the initial wind speed has been increased to 50 kt. An increase in northeasterly shear by tomorrow is expected to temporarily halt the intensification process. However, the shear is expected to decrease after 48 hours, which should allow for strengthening later in the period while Hector remains over warm water. There is still a large spread in the intensity guidance by day 4, with the ECMWF-based SHIPS guidance showing an intensity of around 65 kt, while the HWRF and COAMPS-TC model bring Hector to category 4 strength. Given the large divergence in the intensity guidance at the long range, the NHC forecast remains close to the consensus aids.

Hector continues to move westward at around 10 kt. There has been no significant change to the track forecast reasoning. Hector should move generally westward to the south of a strong subtropical ridge through Friday. The ridge is forecast to build westward by the weekend which is expected to impart a west-southwestward motion through the remainder of the forecast period. The overall track guidance envelope has not changed since the previous advisory and the NHC track forecast is near the middle of the envelope. The latest NHC track prediction is very close to the previous NHC advisory.

Hurricane Hector Position SE Hilo Hawaii August 4 2018

FORECAST POSITIONS AND MAX WINDS

INIT  02/0300Z 14.0N 122.2W   50 KT  60 MPH
 12H  02/1200Z 14.3N 124.0W   55 KT  65 MPH
 24H  03/0000Z 14.4N 126.3W   60 KT  70 MPH
 36H  03/1200Z 14.5N 128.6W   60 KT  70 MPH
 48H  04/0000Z 14.5N 131.0W   65 KT  75 MPH
 72H  05/0000Z 14.0N 135.8W   80 KT  90 MPH - Category 1 (SE Hilo, Hawaii)
 96H  06/0000Z 13.5N 140.5W   90 KT 105 MPH - Category 2 (SE Hilo, Hawaii)
120H  07/0000Z 13.8N 145.0W   90 KT 105 MPH - Category 2 (SE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 200 PM PDT Wed Aug 01 2018 

Hector is moving toward the west near 12 mph (19 km/h) and this motion is expected to continue for the next few days. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Strengthening is forecast during the next few days, and Hector is forecast to become a hurricane on Friday. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1002 mb (29.59 inches).

Hector continues to become better organized. Microwave data indicate that the low- and mid-level centers are now closer together, and visible satellite imagery is showing more curved banding features. Dvorak estimates from TAFB, SAB and the CIMSS ADT are all 45 kt, so that will be the initial intensity. Hector should continue to intensify for the next day or so in a favorable environment of light-to-moderate shear and warm SSTs. However, a surge of northeasterly upper-level flow is forecast to impact the cyclone on Thursday, which will likely arrest the strengthening trend. This stronger flow should abate late Friday or Saturday, leading to further intensification. The latest forecast is below the consensus at shorter range, then above the consensus at long range. There remains the potential that the intensity forecast is too low at days 4 and 5, but the model guidance is too divergent with the upper-level environment at that time to have confidence in raising the forecast.

Scatterometer and microwave data are showing the system moving westward at 10 kt. Hector should continue moving westward overnight and then even move a little south-of-west for the next few days as the subtropical ridge builds to the north and west of the cyclone. The biggest change from 6 hours ago is that the guidance is faster at long range due to the tropical cyclone staying separate from an upper-level trough in the northwestward part of the eastern Pacific. The latest NHC forecast follows the speedier trend of the guidance, but is not as fast as the ECMWF or UKMET models.

FORECAST POSITIONS AND MAX WINDSTropical Storm Hector SE Hilo Hawaii 1400 Hours August 1 2018

INIT  01/2100Z 13.8N 121.2W   45 KT  50 MPH
 12H  02/0600Z 14.1N 122.8W   55 KT  65 MPH
 24H  02/1800Z 14.4N 125.1W   60 KT  70 MPH
 36H  03/0600Z 14.5N 127.4W   60 KT  70 MPH
 48H  03/1800Z 14.5N 129.7W   65 KT  75 MPH
 72H  04/1800Z 14.1N 134.6W   80 KT  90 MPH - Category 1 (SE Hilo, Hawaii)
 96H  05/1800Z 13.5N 139.3W   90 KT 105 MPH - Category 2 (SE Hilo, Hawaii)
120H  06/1800Z 13.5N 143.5W   90 KT 105 MPH - Category 2 (SE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 1605 UTC Wed Aug 01 2018 

Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2145 UTC.

SPECIAL FEATURE… Tropical Storm Hector centered near 13.8N 120.4W at 01/1500 UTC or 930 sm SW of the southern tip of the Baja California Peninsula moving W-NW at 11 kt.

Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Numerous strong convection is observed within 120 nm over the the Se semicircle of the center. Scattered moderate to strong is noted within 90 nm over the NW semicircle.

National Hurricane Center Miami FL 800 AM PDT Wed Aug 01 2018

Satellite images indicate that Hector is on a strengthening trend, with a large area of convection near and west of the apparent center. The latest microwave data, a 1159Z F-16 pass, also show the beginnings of an inner core in the 91-Ghz channels. The system has some tilt, however, with suggestions from the microwave pass that the low- and mid-level centers are not well aligned. The latest intensity estimates from TAFB/SAB are 45 kt, but I’ve elected to only raise the wind speed to 40 kt due to uncertainty in the initial position and the microwave tilt.

Hector is forecast to remain over warm water, with light-to- moderate shear and somewhat dry mid-level moisture for the next several days. In 12 to 24 hours, northeasterly shear is forecast to increase near Hector, which should slow the intensification rate. Thus the official forecast shows strengthening at less than a climatological rate for the next few days. At long range, some of model guidance suggest the upper-level environment could become very favorable, with the HWRF/HMON now showing Hector at category 4 strength in the central Pacific Ocean. I would prefer to see more consistency from these models before showing such a large increase, but the new forecast is raised from the previous one and is higher than the model consensus.

The storm is moving west-northwestward at 11 kt. Hector should turn to the west tomorrow and even move a little south-of-west for the next few days thereafter as the subtropical ridge builds to the north and west of the cyclone. The largest uncertainty is the location of Hector in a few days as an inverted upper-level trough forms to the north or northeast of the cyclone. For now there is enough separation of Hector and this trough to prevent the cyclone from gaining much latitude. While the model guidance doesn’t show a lot of spread for now, and the new forecast is close to the previous one, it is worth keeping an eye on the trough to make sure it stays separate from Hector at long range.Tropical Storm Hector SE Hilu Hawaii 0800 Hours August 1 31 2018

FORECAST POSITIONS AND MAX WINDS

INIT  01/1500Z 13.8N 120.4W   40 KT  45 MPH
 12H  02/0000Z 14.2N 122.0W   50 KT  60 MPH
 24H  02/1200Z 14.5N 124.1W   55 KT  65 MPH
 36H  03/0000Z 14.6N 126.4W   60 KT  70 MPH
 48H  03/1200Z 14.5N 128.7W   65 KT  75 MPH
 72H  04/1200Z 14.4N 133.5W   75 KT  85 MPH
 96H  05/1200Z 13.9N 138.2W   90 KT 105 MPH - Category 2 (SE Hilo Hawaii)
120H  06/1200Z 13.7N 142.0W   90 KT 105 MPH - Category 2 (SE Hilo Hawaii)

NWS National Hurricane Center Miami FL 200 AM PDT Wed Aug 01 2018

Hector is still somewhat disorganized, with a majority of its deep convection displaced to the south and west of its surface center. In fact, a recent AMSU pass around 0515 UTC indicated that the center of Hector was nearly exposed on the northeast side of a small curved band. Dvorak classifications from TAFB and SAB have not changed since the last advisory and the ASCAT instruments missed the cyclone once again, so the initial intensity has been held at 35 kt.

Easterly shear of around 10 kt, as analyzed in SHIPS diagnostics, appears to be the primary factor preventing Hector from becoming better organized. The latest GFS and ECMWF runs at 00Z suggest that the shear will increase slightly during the next 24-36 hours before decreasing substantially during the second half of the forecast period. Despite the shear, all of the intensity guidance forecasts that Hector will intensify in an otherwise favorable environment, and the intensity guidance is generally higher than it was previously. The dynamical hurricane models, HWRF, HMON, and COAMPS-TC all bring Hector to near major hurricane strength, while SHIPS and LGEM are a little lower. Given that Hector is still fairly disorganized, the intensity forecast for the first 24 hours is somewhat conservative, and favors the statistical-dynamical models. Beyond that time, the NHC intensity forecast is a little higher than it was previously, but is still just below the intensity consensus.Tropical Storm Hector SE Hilo Hawaii 0200 Hours August 1 31 2018

The estimated initial motion of the tropical storm is 285/13 kt. Little change has been made to the track forecast, which has been adjusted only slightly to the north through most of the forecast period. The track guidance is in very good agreement on the track of Hector, and the main source of uncertainty is the speed at which an extensive mid-level ridge to the north will steer the cyclone westward. Since I see no obvious reason to favor any one of the typically-reliable global models, the NHC forecast is now very close to the various consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 13.4N 119.4W   35 KT  40 MPH
 12H  01/1800Z 13.9N 121.1W   40 KT  45 MPH
 24H  02/0600Z 14.2N 123.2W   50 KT  60 MPH
 36H  02/1800Z 14.4N 125.2W   60 KT  70 MPH
 48H  03/0600Z 14.4N 127.5W   65 KT  75 MPH (SE Hilo Hawaii)
 72H  04/0600Z 14.3N 132.0W   75 KT  85 MPH (SE Hilo Hawaii)
 96H  05/0600Z 14.0N 136.0W   80 KT  90 MPH (SE Hilo Hawaii)
120H  06/0600Z 14.0N 140.0W   80 KT  90 MPH (SE Hilo Hawaii)

NWS National Hurricane Center Miami FL 800 PM PDT Tue Jul 31 2018

Deep convection associated with the tropical cyclone  has continued to become better organized since the previous advisory with an increase in banding over the western and southern portions of the circulation. As a result, satellite intensity estimates have increased to T2.5 on the Dvorak scale, so the initial wind speed has been increased to 35 kt. Hector becomes the eighth named storm of the 2018 eastern North Pacific hurricane season.

Hector is forecast to traverse warm SSTs and remain within a favorable upper-level wind pattern during the next day or so which should result in steady strengthening. Some moderate northeasterly shear could temper the rate of intensification in 36-48 h, but the intensity guidance is generally more aggressive this cycle. The NHC intensity forecast calls for a faster rate of strengthening early in the forecast period, and brings Hector to hurricane status in a couple of days, which is in line with most of the intensity guidance. The updated official forecast also indicates a slightly higher peak intensity, but it is not as high as the dynamical model guidance and the ICON intensity consensus model in deference to the previous NHC advisory.

Recent satellite fixes indicate that Hector is moving west- northwestward or 285/12 kt. A strong deep-layer ridge to the north of the tropical storm is expected to keep the system on a generally west-northwestward to westward motion throughout the forecast period. The track guidance is in good agreement on this scenario, but there are some differences in the predicted forward speed of the cyclone. The ECMWF depicts a faster westward motion while the GFS, GFS ensemble mean, and HWRF show a somewhat slower speed. The new NHC track forecast is a little faster than the previous official forecast, but is slower than most of the consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 13.0N 118.2W   35 KT  40 MPH
 12H  01/1200Z 13.4N 119.9W   45 KT  50 MPH
 24H  02/0000Z 13.8N 122.0W   55 KT  65 MPH
 36H  02/1200Z 13.9N 124.0W   60 KT  70 MPH
 48H  03/0000Z 13.9N 126.1W   65 KT  75 MPH
 72H  04/0000Z 13.8N 130.1W   70 KT  80 MPH
 96H  05/0000Z 13.7N 134.0W   75 KT  85 MPH
120H  06/0000Z 13.7N 138.0W   70 KT  80 MPH (SSE Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 PM PDT Tue Jul 31 2018

The low pressure area previously located about 800 miles south- southwest of the southern tip of the Baja California Peninsula  is upgraded to Tropical Depression Ten-E at 2100 UTC. At this  time, the depression is centered near 12.7N 116.7W moving WNW or 290 degrees at 11 KT. This general motion is expected to continue for the next couple of days, followed by a turn toward the west  thereafter.

Estimated minimal central pressure is 1007 mb.  Maximum sustained wind speed is 30 kt with gusts to 40 kt. Some  strengthening is forecast during the next 48 hours, and the  depression is forecast to become a tropical storm by Wednesday.  Satellite imagery shows numerous moderate to isolated strong  convection within 150 nm NW and 75 nm SE semicircles of center.

For the eastern North Pacific…east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on newly formed Tropical Depression Ten-E, located more than 800 miles southwest of the southern tip of the Baja California Peninsula. If Tropical Depression Ten-E is named, it will be Tropical Storm Hector.

1. An area of low pressure is expected to form several hundred miles south of the Gulf of Tehuantepec late this week. Environmental conditions are expected to be conducive for gradual development of this system over the weekend while it moves west-northwestward off the coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Tue Jul 31 2018

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

1. Showers and thunderstorms associated with an area of low pressure located about 800 miles south-southwest of the southern tip of the Baja California Peninsula continue to show signs of organization. Environmental conditions appear conducive for additional development, and a tropical depression is likely to form within the next few days while the disturbance moves generally westward at around 15 mph.
* Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high...70 percent.

2. An area of low pressure is expected to form several hundred miles south of the Gulf of Tehuantepec late this week. Gradual development of this system is possible thereafter as it moves west-northwestward off the coast of Mexico.
* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Mon Jul 30 2018

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

1. A low pressure system located several hundred miles southwest of Manzanillo, Mexico, is producing a concentrated area of showers and thunderstorms. Environmental conditions are expected to gradually become more conducive for development, and a tropical depression could form during the next few days while the disturbance moves generally westward at around 15 mph. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…medium...60 percent.

2. An area of low pressure is expected to form several hundred miles south of the Gulf of Tehuantepec late this week. Gradual development of this system is possible thereafter as it moves west-northwestward off the coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Mon Jul 30 2018

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

1. A trough of low pressure located several hundred miles southwest of Manzanillo, Mexico, is producing a small area of showers and thunderstorms. Environmental conditions are currently only marginally favorable and any development should be slow to occur over the next couple of days. By mid-week, conditions could become a little more conducive for development while the system moves westward to west-northwestward at 10 to 15 mph. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium...50 percent.

2. An area of low pressure is expected to form several hundred miles south of the Gulf of Tehuantepec late this week. Gradual development of this system is possible thereafter as it moves west-northwestward off the coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 800 AM PDT Fri Jul 27 2018

Satellite images indicate that the circulation of the depression is no longer closed and instead now resembles an northeast-southwest oriented trough. This system is also well embedded in the Intertropical Convergence Zone, an indication that it is not a discrete cyclone. Therefore, this system does not qualify as a tropical cyclone, and this is the last advisory issued by the National Hurricane Center. The initial intensity is lowered to 25 kt, in general agreement with the Dvorak estimates. The remnants of the cyclone are moving westward at 11 kt, and the trough is expected to move into the Central Pacific basin later today.

NWS National Hurricane Center Miami FL 200 PM PDT Thu Jul 26 2018

Satellite data indicate that the low pressure system located over the far western portion of the eastern Pacific basin has developed sufficient organization to be classified a tropical depression nine, one of the season and second one of the afternoon. The initial intensity is set to 30 kt. Although the depression is expected to be over warm SSTs and in a moist environment during the next few days, strong northerly shear should prevent strengthening.

The intensity guidance shows little change in strength through the forecast period, and most of the global models show the system opening into a trough within the next few days. Based on this information, the NHC official intensity forecast shows a steady 30-kt depression through the period, but it would not be surprising if the cyclone dissipated sometime in the forecast period. The depression is moving to the west at 12 kt steered by the flow on the south side of a mid-level ridge. This general motion is expected during the next several days, taking the system into the central Pacific basin in 24 to 36 hours, and well south of the Hawaiian Islands in 4 to 5 days. The NHC track forecast lies near the various consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 11.0N 135.5W   30 KT  35 MPH
 12H  27/0600Z 10.9N 137.0W   30 KT  35 MPH
 24H  27/1800Z 10.8N 139.0W   30 KT  35 MPH
 36H  28/0600Z 10.7N 141.2W   30 KT  35 MPH
 48H  28/1800Z 10.8N 143.4W   30 KT  35 MPH
 72H  29/1800Z 11.8N 148.1W   30 KT  35 MPH
 96H  30/1800Z 12.8N 153.4W   30 KT  35 MPH (SE Hilo, Hawaii)
120H  31/1800Z 13.5N 159.5W   30 KT  35 MPH (SW Hilo, Hawaii)

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Video: Big Waves As Hurricane Hector Passes Hawaii

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