Tropical Storm Erick

Tropical Depression Erick Track 0500 hours August 4 2019
Tropical Depression Erick Track 0500 hours August 4 2019

Hurricane Erick Satellite 1700 Hours July 31 2019Tropical Storm Erick – NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Sun Aug 04 2019

Deep convection has again developed over Erick’s (see  Friday video below) low-level circulation center (LLCC) early this morning. This not only makes finding the latest position of the LLCC problematic, it makes diagnosing the current intensity somewhat uncertain. The westerly wind shear continues in the 40-50 kt range according to the latest SHIPS and CIMSS estimates, which is creating hostile environmental conditions over the depression. However, this is also likely allowing the thunderstorms to periodically flare-up in the vicinity of the tropical cyclone. The most recent Dvorak intensity estimates from the satellite fix agencies were 2.0/30 kt from PHFO and SAB, and 1.5/25 kt from JTWC. The CIMSS ADT estimate was 2.3/33 kt. Last evening, a 0747Z ASCAT pass showed a large swath of 30 kt winds in Erick’s northeast quadrant. Therefore, we are keeping the depression’s initial intensity at 30 kt for this advisory.

The initial forward motion for this advisory has apparently slowed during the past 6-12 hours, and it is now 290/10 kt. The LLCC is primarily being steered by the low-level flow, which is dominated by a large subtropical ridge far north of Erick. Note that if there are additional episodes of deep convection developing near the LLCC, there may be slight deviations in the forward motion toward the west-northwest. However, we have kept the track forecast very close to the previous advisory through 24 hours, followed by a slight shift to the left at a slower forward speed in 36 hours.

The strong vertical wind shear over Erick will not decrease during the next few days. Therefore, we do not anticipate any significant intensification of the system. The latest intensity forecast is the same as the previous package. Erick is expected to remain a tropical depression today, then become a post-tropical remnant low by tonight, before dissipation on Monday.

FORECAST POSITIONS AND MAX WINDS

INIT  04/1500Z 18.5N 167.1W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 12H  05/0000Z 19.1N 168.3W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 24H  05/1200Z 19.7N 169.8W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 36H  06/0000Z 20.0N 171.1W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 48H  06/1200Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Sat Aug 03 2019

The low-level circulation center (LLCC)  is once again exposed late this evening after being partially obscured by a burst of deep convection for several hours. This deep convection was likely induced due to the very strong winds aloft over Erick. However, these winds are continuing to create hostile environmental conditions for the depression, since the westerly shear is 40 to 50 kt according to latest SHIPS and CIMSS estimates. Dvorak intensity estimates from the satellite fix agencies were 2.0/30 kt from PHFO, and 1.5/25 kt from SAB and JTWC. The most recent CIMSS ADT estimate was 2.3/33 kt. A 0747Z ASCAT pass showed a large swath of 30 kt or greater winds in the northeast quadrant of a well-defined circulation. As a result, we have kept Erick’s initial intensity at 30 kt for this advisory.

The initial motion for this advisory remains 290/12 kt. The LLCC is primarily being steered by the low level flow, which is dominated by a large subtropical ridge far north of Erick. There is a possibility that additional episodes of deep convection may develop near the center, which may cause slight deviations in the west-northwestward motion. However, we have kept the forecast track similar to the previous forecast package.

The strong vertical wind shear over Erick will not decrease during the next few days. Therefore, we do not see any chance for the intensification of the system. The latest intensity forecast is the same as the previous package. Erick is expected to remain a tropical depression through early Sunday, then become a post-tropical remnant low late Sunday, before dissipation on Monday.

FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 18.2N 166.3W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 12H  04/1800Z 19.0N 167.6W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 24H  05/0600Z 19.7N 169.3W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 36H  05/1800Z 20.4N 170.9W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 48H  06/0600Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Sat Aug 03 2019

Deep convection briefly developed over the low-level circulation center of Erick overnight, with the tropical cyclone then accelerating westward as the convection collapsed. Strong west-southwesterly shear continues to affect the tropical cyclone, with the latest UW-CIMSS vertical wind shear analysis indicating 45 knots of shear over the system. The latest current intensity estimates from the satellite agencies were a unanimous 2.5/35 knots, with the Advanced Dvorak Technique coming in at 2.7/39 knots. As a result, the initial intensity for this advisory has been held at 35 knots, keeping Erick a Tropical Storm. The initial motion is somewhat uncertain due to the interaction with the pulsing deep convection overnight, and has been set at 275/12 knots.

Erick is being steered westward by a low-mid level ridge to the north. The increasingly shallow system is expected to make a turn toward the west-northwest shortly, with this general motion then continuing through Sunday at a slightly slower forward speed. The forecast track was adjusted to the south of previous official track due to the acceleration westward overnight resulting from the collapse of the deep convection that developed. The track forecast is near or slightly to the south of the consensus guidance.

Strong west-southwesterly vertical wind shear will continue to weaken Erick over the next couple days. The tropical cyclone is expected to become a Tropical Depression later today, a remnant low tonight, with dissipation into a trough expected Sunday night. The intensity forecast was unchanged from the previous advisory and remains closely aligned with the latest statistical guidance through dissipation.

FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 17.1N 162.8W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  04/0000Z 17.8N 164.4W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 24H  04/1200Z 18.8N 166.1W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 36H  05/0000Z 19.6N 167.8W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 48H  05/1200Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Fri Aug 02, 2019

Erick  is barely holding on to tropical storm status this evening, as relentless strong west-southwesterly vertical wind shear continues to hammer the system. The latest UW-CIMSS vertical wind shear analysis shows 42 knots of shear over the system, with 50 to 60 knots of shear just to the north of the system. The latest current intensity estimates from the satellite agencies were a unanimous 2.5/35 knots, with the Advanced Dvorak Technique coming in at 2.9/43 knots. The initial intensity for this advisory has been held at 35 knots, with the initial motion set at 280/12 knots.

Erick is being steered westward by a low-mid level ridge to the north. The system is expected to continue to track westward tonight, with a turn toward the west-northwest forecast as Erick rounds the southwestern periphery of the ridge. The track forecast has been nudged to the south of the previous track through the first 12 hours due to the more westward initial motion, then is very close to the previous official forecast thereafter. This track forecast is to the south of the consensus guidance which seems to be influenced by the GFS which is a northern outlier.

Strong west-southwesterly vertical wind shear will continue to weaken Erick over the next couple days. The tropical cyclone is expected to weaken to a Tropical Depression later tonight or Saturday morning, then become a remnant low late Saturday or Saturday night, with dissipation into a trough expected late Sunday or Sunday night. The intensity forecast is closely aligned with the latest statistical guidance through dissipation.

FORECAST POSITIONS AND MAX WINDS

INIT  03/0900Z 17.3N 160.9W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 12H  03/1800Z 17.7N 162.7W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 24H  04/0600Z 18.8N 164.7W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 36H  04/1800Z 19.7N 166.7W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 48H  05/0600Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Fri Aug 02 2019

Deep convection has managed to develop over the low level circulation center (LLCC) of Erick this morning, after the center was exposed for much of the night. Strong west-southwesterly vertical wind shear continues to affect the tropical cyclone however, and the UW-CIMSS vertical wind shear analysis shows 42 knots of shear over the system. The latest subjective Dvorak current intensities estimates from the satellite agencies came in at 3.0 (45 knots) from PHFO/SAB and 3.5 (55 knots) from JTWC, while the Advanced Dvorak Technique (ADT) from UW-CIMSS was 2.6 (37 knots). Based on a blend of these estimates the initial intensity of Erick has been lowered to 45 knots with this advisory. Although the center was difficult to locate overnight due to high level cloud cover moving over the LLCC, a timely GPM pass at 1136Z and a VIIRS day/night band pass at 1140Z assisted in locating the center. The motion has been set at 285/12 knots.

Erick is forecast to track west-northwest through tonight around the southwestern periphery of a large subtropical ridge. A turn toward the northwest at a slower forward speed is expected over the weekend as the tropical cyclone begins to interact with a digging upper level trough in the vicinity of 165W. The LLCC may deviate slightly north and/or south of the forecast track at times due to bursts of deep convection resulting from the system passing over increasingly favorable sea surface temperatures and higher ocean heat content values. It should be noted however, that conditions will remain extremely hostile, and intensification is not expected. The latest forecast track is very close to the previous official forecast and was closely aligned with the latest TVCN and HCCA track consensus guidance.

Strong vertical wind shear will continue to hammer Erick over the next several days. Despite the shear, periodic bursts of deep convection will likely result in slow weakening of the tropical cyclone. Erick is forecast to weaken into a tropical depression by Sunday, and become a post-tropical remnant low Sunday night. Dissipation into a trough is now forecast to occur by Monday night. The intensity forecast was lowered slightly initially but remains very close to the previous official forecast tonight through the weekend. This intensity forecast remains roughly a blend of the latest statistical and dynamical intensity consensus guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  02/1500Z 16.8N 157.4W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  03/0000Z 17.2N 159.0W   40 KT  45 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  03/1200Z 17.9N 161.0W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 36H  04/0000Z 18.9N 163.0W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 48H  04/1200Z 19.9N 164.6W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 72H  05/1200Z 21.3N 166.7W   25 KT  30 MPH - Tropical Depression (ESE Hilo, Hawaii)
 96H  06/1200Z...POST-TROP/REMNT LOW

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Thu Aug 01 2019

Deep convection remains well to the northeast of the low-level circulation center (LLCC) of Erick this evening due to persistent strong west-southwesterly vertical wind shear of around 37 knots as depicted by the latest UW-CIMSS vertical wind shear analysis. The latest subjective Dvorak current intensities estimates from the satellite agencies came in at 3.5 (55 knots) from PHFO/SAB and 4.0 (65 knots) from JTWC, while the Advanced Dvorak Technique (ADT) from UW-CIMSS was 3.7 (59 knots).

These estimates in combination with the degradation in satellite appearance warrants lowering the initial intensity of Erick to 55 knots with this advisory. Although the center is difficult to locate in conventional infrared satellite imagery, shortwave infrared imagery was useful in determining the center location. The motion has been set at 290/11 knots.

Erick is forecast to track west-northwestward over the next couple days around the southwestern periphery of a large subtropical ridge. Beyond 48 hours, a turn toward the northwest is expected at a slower forward speed as the tropical cyclone begins to interact with a digging upper level trough in the vicinity of 165W. The LLCC may deviate slightly north of the forecast track at times due to bursts of deep convection resulting from the system passing over increasingly favorable sea surface temperatures and higher ocean heat content values. It should be noted however, that conditions remain extremely hostile, and intensification is not expected. The latest forecast track is very close to the previous official forecast and is closely aligned with the latest TVCN and HCCA track consensus guidance.

Strong vertical wind shear will continue to hammer Erick over the next several days, with rapid weakening expected to continue tonight, followed by slow weakening thereafter. Erick is expected to become a tropical depression by Sunday, a post-tropical remnant low by Monday and dissipate into a trough by Tuesday. The intensity forecast was left virtually unchanged, and is roughly a blend of the latest statistical and dynamical intensity consensus guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 16.4N 155.8W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  02/1800Z 16.8N 157.6W   45 KT  50 MPH - Tropical Storm (ESE Hilo, Hawaii)
 24H  03/0600Z 17.4N 159.8W   40 KT  45 MPH - Tropical Storm (ESE Hilo, Hawaii)
 36H  03/1800Z 18.3N 161.9W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 48H  04/0600Z 19.3N 163.8W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
 72H  05/0600Z 21.1N 166.1W   30 KT  35 MPH - Tropical Depression (ESE Hilo, Hawaii)
 96H  06/0600Z 22.0N 167.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  07/0600Z...DISSIPATED

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Thu Aug 01 2019

Although Erick  has the overall appearance of a hurricane facing an increasing amount of headwind, deep convection near the center has thus far prevented the environmental wind shear from disrupting the inner core. Southwesterly shear near 20 kt is limiting outflow in the southwest semicircle, but a burst of thunderstorms over the center led to the development of a cloud-filled eye right around analysis time. These strong thunderstorms and eye feature have since persisted, but the southern portion of the eyewall looks degraded in latest satellite images, and in an 1119Z ATMS pass. Given those developments, and using a blend of the subjective and automated Dvorak intensity estimates from PHFO/SAB/PGTW/UW-CIMSS, the initial intensity for this advisory has been lowered slightly to 75 kt.

Tracking the cloud-filled eye leads to increased confidence in the initial motion estimate of 285/13 kt. The track forecast continues to expect a general motion just north of due west for most of the forecast period, with a low- to mid-level ridge centered to the north and northeast respectively providing the primary steering, especially as Erick becomes increasingly shallow. A turn toward the northwest, with some slowing in forward speed, is expected on days 4 and 5 as the ridge to the north weakens and lifts north. The updated track forecast has changed little from the previous, and is close to the ECMWF and HCCA guidance.

Erick is moving into an area of even stronger vertical wind shear, associated with a semi-permanent upper-level trough northwest of the main Hawaiian islands. Shear values along the forecast track increase to 30-40 kt over the next 12 to 24 hours, and this unrelenting shear is expected to lead to the demise of Erick as a tropical cyclone. The bulk of the dynamical and statistical guidance indicates that Erick will barely be hanging on as a tropical storm in 48 hours, and the official forecast closely follows. Erick is then expected to become a remnant low on days 4 and 5 before dissipating shortly thereafter.

Erick is currently passing about 100 nm south of NOAA buoy 51004, which is reporting seas over 14 feet and is still about 375 nm east-southeast of buoy 51002, where seas have reached 11 feet. This data was used to increase the radii of 12 foot seas in the northwest semicircle. A partial ASCAT pass around 0733Z led to a reduction to the 34 kt radii in the northern semicircle. Six-hourly soundings will begin at PHTO later today.

FORECAST POSITIONS AND MAX WINDS

INIT  01/1500Z 15.9N 152.4W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 12H  02/0000Z 16.1N 154.5W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
 24H  02/1200Z 16.6N 157.2W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  03/0000Z 17.2N 159.8W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 48H  03/1200Z 17.7N 162.2W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 72H  04/1200Z 19.4N 165.6W   30 KT  35 MPH - Tropical Depression (WSW Hilo, Hawaii)
 96H  05/1200Z 21.0N 168.0W   30 KT  35 MPH - Tropical Depression (WSW Hilo, Hawaii)
120H  06/1200Z 22.5N 170.0W   25 KT  30 MPH - Tropical Depression (WSW Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Wed Jul 31,  2019

Although Erick’s presentation in conventional infrared satellite imagery continues to deteriorate this evening, deep convection persists over the core, and microwave imagery (especially a 0357Z SSMIS pass) indicates that an eye remains intact. Subjective Dvorak estimates agree that Erick remains a hurricane, with a blend of these estimates supporting an initial intensity of 80 kt for this advisory, although ADT and SATCON from UW-CIMSS suggest that Erick is weaker.

Locating the center of the hurricane is somewhat uncertain, leading to reduced confidence in an initial motion estimate of 290/11 kt. The track forecast continues to expect a general motion just north of due west for most of the forecast period, with a low- to mid-level ridge centered to the north and northeast respectively providing the primary steering, especially as Erick becomes increasingly shallow. The official forecast was nudged equatorward and is a little faster than the previous forecast through the first 72 hours, close to the UKMET and ECMWF, which have the been the top performers with Erick to this point. Thereafter, little change to the forecast was made.

Erick is moving into an area of strong vertical wind shear, with low-level easterlies supported by the ridge to the north, and upper- level westerlies associated with a semi-permanent trough axis northwest of the main Hawaiian islands. According to UW-CIMSS analyses, shear values along the forecast track increase to 30-40 kt over the next 12 to 24 hours. This unrelenting shear is expected to lead to the demise of Erick as a tropical cyclone by the end of the forecast period. The dynamical and statistical guidance indicates that Erick’s recent rapid decay will continue, and it will barely be hanging on as a tropical storm in 48 hours. The rate of weakening depicted in the official forecast closely follows, and Erick is now expected to become a remnant low on days 4 and 5 before dissipating shortly thereafter.

FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 15.5N 150.9W   80 KT  90 MPH - Category 1 (ESE Hilo, Hawaii)
 12H  01/1800Z 15.7N 152.6W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)
 24H  02/0600Z 16.2N 155.3W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  02/1800Z 16.6N 158.0W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 48H  03/0600Z 17.2N 160.4W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 72H  04/0600Z 18.6N 164.5W   30 KT  35 MPH - Tropical Storm (WSW Hilo, Hawaii)
 96H  05/0600Z 20.0N 167.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  06/0600Z 21.5N 169.5W   25 KT  30 MPH...POST-TROP/REMNT LOW

NWS Central Pacific Hurricane Center Honolulu HI 500 PM HST Wed Jul 31, 2019

Hurricane Erick is slowly weakening as seen in recent satellite imagery with the eye becoming cloud-filled. Subjective Dvorak current intensity estimates from all fix sites came in at 4.5/77 kt. The initial intensity estimate for this advisory has been decreased 90 kt which may be a big generous. Erick continues moving slightly north of due west with little change in forward speed. The initial motion estimate for this advisory is 280 degrees at 14 mph.

The track guidance remains tightly clustered through 72 hours with some divergence in the guidance on days 4 and 5. The latest forecast track has changed little from the previous forecast through 72 hours with a slightly north of due west motion expected as a strong subtropical ridge remains north of the main Hawaiian Islands. The track forecast for days 4 and 5 has been adjusted slightly to the left of the previous forecast which is in line with most of the reliable model guidance.

The intensity guidance remains consistent indicating a gradual weakening trend through the entire forecast period. This is due to an upper trough just north of the main Hawaiian Islands which is inducing southwesterly wind shear over the system. The UW-CIMSS vertical shear magnitude is currently 22 kt from the southwest. As the system continues moving toward the west-northwest, the shear is forecast to increase with Erick weakening to a tropical depression in about 96 hours.

FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 15.1N 149.6W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)
 12H  01/1200Z 15.5N 151.3W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 24H  02/0000Z 16.1N 153.7W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  02/1200Z 16.6N 156.2W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 48H  03/0000Z 17.1N 158.6W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
 72H  04/0000Z 18.4N 163.3W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 96H  05/0000Z 19.9N 166.9W   30 KT  35 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  06/0000Z 21.0N 169.6W   30 KT  35 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Wed Jul 31, 2019

Hurricane Erick is showing signs of weakening in recent satellite imagery. Subjective Dvorak current intensity estimates were 4.5/77 kt from PHFO, 5.0/90 kt from JTWC and 5.5/102 kt from SAB. The initial intensity estimate for this advisory has been decreased slightly to 100 kt. Erick continues moving slightly north of due west with little change in forward speed. The initial motion estimate for this advisory is 289 degrees at 14 mph.

The track guidance is tightly clustered through 72 hours with some divergence in the guidance on days 4 and 5. The latest forecast track has changed little from the previous forecast through 72 hours with a slightly north of due west motion expected due to a strong subtropical ridge north of the main Hawaiian Islands. The track forecast for days 4 and 5 has been adjusted to the left of the previous forecast which is in line with most of the reliable model guidance.

The intensity guidance remains consistent indicating a gradual weakening trend through the entire forecast period. This is due to an upper trough just north of the main Hawaiian Islands which is inducing southwesterly wind shear over the system. The UW-CIMSS vertical sheer magnitude is currently 20 kt from the southwest. As the system continues moving toward the west-northwest, the shear is forecast to increase with Erick weakening to a tropical depression by day 5.

FORECAST POSITIONS AND MAX WINDS

INIT  31/2100Z 14.8N 148.8W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 12H  01/0600Z 15.2N 150.5W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)
 24H  01/1800Z 15.7N 152.8W   75 KT  85 MPH - Category 1 (ESE Hilo, Hawaii)
 36H  02/0600Z 16.2N 155.3W   65 KT  75 MPH - Category 1 (ESE Hilo, Hawaii)
 48H  02/1800Z 16.7N 157.8W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 72H  03/1800Z 18.3N 162.1W   40 KT  45 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
 96H  04/1800Z 20.1N 166.1W   35 KT  40 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
120H  05/1800Z 21.7N 169.0W   30 KT  35 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Tue Jul 30, 2019

Hurricane Erick now appears less impressive on satellite imagery. The eye has become colder and less distinct and the area of coldest cloud tops over the center has shrunk and became less symmetrical. Subjective Dvorak current intensity estimates were 6.0/115 kt from SAB and JTWC and 5.5/102 kt from PHFO, while ADT is 5.6. The initial intensity estimate for this advisory has been decreased slightly to 110 kt. Erick is now a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Erick has tracked slightly north of west and slowed slightly. The initial motion estimate for this advisory is 280/10 kt.

There has been little change in the philosophy for the forecast track or intensity. Guidance remains consistent showing Erick moving tracking slightly north of west for the next 48 hours as it moves along south of a strong subtropical ridge, then gradually turning towards the northwest. That track will take Erick over slightly cooler water and into an area of stronger vertical wind shear associated with a persistent trough aloft. That environment is expected to produce steady weakening.

FORECAST POSITIONS AND MAX WINDS

INIT  31/0900Z 14.2N 146.3W  110 KT 125 MPH - Category 3 (ESE Hilo, Hawaii)
 12H  31/1800Z 14.6N 147.9W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 24H  01/0600Z 15.2N 150.0W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 36H  01/1800Z 15.8N 152.4W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 48H  02/0600Z 16.3N 155.1W   60 KT  70 MPH - Tropical Storm (ESE Hilo, Hawaii)
 72H  03/0600Z 17.4N 159.8W   40 KT  45 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
 96H  04/0600Z 18.9N 163.6W   35 KT  40 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)
120H  05/0600Z 20.5N 166.3W   30 KT  35 MPH - Tropical Storm (WSW Puʻuwai, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 PM HST Tue Jul 30, 2019

The rapid intensification of Erick  has waned this afternoon, but it still remains a powerful category 4 hurricane. Satellite images show that the eye has become cloud-filled and elongated since the last advisory, with outflow somewhat restricted in the southwestern semicircle. On the other hand, outflow in the northeastern semicircle appears optimal, and the eyewall convection has been a prolific lightning producer through the day. Subjective Dvorak current intensity estimates range from 6.0/115 kt from SAB/PHFO to 6.5/127 kt from PGTW, while ADT is also now near 6.0. The initial intensity estimate for this advisory has been held at 115 kt.

A gradual turn toward the west-northwest has taken place today, and the initial motion estimate for this advisory is 290/13 kt. There is not much change to the ongoing track forecast philosophy, and only minor changes were made to the official forecast, despite increasing model spread in the later forecast periods. A track toward the west-northwest is expected over the next 24 hours or so, with a subtle turn toward the west on days 2 and 3, before a turn back to the west-northwest occurs on days 4 and 5. Initially, the the strong hurricane will be steered by the deep-layer flow, with southwest winds in the upper levels helping Erick to gain latitude. As these winds shear the cyclone, it is expected to become increasingly shallow, steered by a low- to mid-level ridge to the north, which will induce the westward track. As the weakened cyclone reaches the western edge of the ridge on days 4 and 5, it is expected to resume a motion toward the west-northwest, but forecast models disagree as to the extent of the poleward motion. The official forecast lies closest to HCCA guidance, with the 5-day forecast point almost on top of the UKMET ensemble guidance.

The window for further intensification appears to be closing, as increased vertical wind shear (20 kt increasing to 40 kt) lies along the forecast track, especially after about 24 hours. Once Erick encounters this southwesterly to westerly shear, associated with a semi-permanent trough aloft northwest of Hawaii, significant weakening is expected. In the meantime, Erick is expected to change little, but it wouldn’t be surprising to see the eye clear out again overnight. The updated intensity forecast closely follows HCCA and FSSE guidance. An 1845Z partial ASCAT pass was used to expand 34 kt wind radii, mainly in the northern semicircle.

FORECAST POSITIONS AND MAX WINDS

INIT  31/0300Z 14.0N 145.4W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 12H  31/1200Z 14.5N 147.0W  115 KT 130 MPH - Category 4 (ESE Hilo, Hawaii)
 24H  01/0000Z 15.1N 149.2W  100 KT 115 MPH - Category 3 (ESE Hilo, Hawaii)
 36H  01/1200Z 15.6N 151.7W   90 KT 105 MPH - Category 2 (ESE Hilo, Hawaii)
 48H  02/0000Z 16.1N 154.0W   70 KT  80 MPH - Category 1 (ESE Hilo, Hawaii)
 72H  03/0000Z 17.1N 158.9W   40 KT  45 MPH - Tropical Storm (ESE Hilo, Hawaii)
 96H  04/0000Z 18.6N 163.1W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)
120H  05/0000Z 20.0N 166.0W   35 KT  40 MPH - Tropical Storm (ESE Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 AM HST Tue Jul 30, 2019

Convection consolidated over the center of Hurricane Erick  as the sunset on Monday, and the hurricane has rapidly intensified since then. Satellite imagery shows a persistent warm eye surrounded by a solid ring of deep convection that is producing bursts of eyewall lightning, indicating that the intensification trend continues. Subjective Dvorak intensity estimates are 6.0/115 kt, leading to an initial intensity estimate of 115 kt, making Erick a category 4 hurricane.

The window for further intensification appears to be small, as increased vertical wind shear (30-40 kt) lies along the forecast track, especially after about 36 hours. Once Erick encounters this southwesterly shear, associated with a semi-permanent upper-level trough northwest of Hawaii, a rapid weakening trend is expected. In the meantime, slight intensification is anticipated, although an eyewall replacement cycle cannot be completely ruled out. Latest intensity guidance supports the ongoing forecast, and little significant change was made to the official forecast, which closely follows trends presented by the intensity consensus IVCN.

The forward motion of the cyclone has slowed since yesterday, and the initial motion estimate for this advisory is 275/13 kt. In the mid-levels, Erick is being steered by a ridge to the north that is expected to build westward over the next couple of days. A slight turn to the west-northwest and some slowing in forward speed is expected in the short term as Erick remains a strong hurricane interacting with the deep-layer flow. There are still notable differences amongst the track models through this time frame, with HWRF/COAMPS-TC to the right of the official forecast, and ECMWF to the left. With most guidance tending to be too slow and poleward to this point, the official forecast was nudged equatorward, closer to the well-performing ECMWF guidance, and close to FSSE/HCCA.  Toward the end of the forecast period, Erick will reach the western periphery of the ridge, allowing the weakened cyclone to gain latitude.

FORECAST POSITIONS AND MAX WINDS

INIT  30/2100Z 13.6N 144.1W  115 KT 130 MPH - Category 4 (WSW Hilo, Hawaii)
 12H  31/0600Z 14.2N 145.8W  125 KT 145 MPH - Category 4 (WSW Hilo, Hawaii)
 24H  31/1800Z 14.9N 147.9W  115 KT 130 MPH - Category 4 (WSW Hilo, Hawaii)
 36H  01/0600Z 15.3N 150.2W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 48H  01/1800Z 15.8N 152.5W   85 KT 100 MPH - Category 2 (ESE Hilo, Hawaii)
 72H  02/1800Z 16.8N 157.5W   50 KT  60 MPH - Tropical Storm (WSW Ocean View , Hawaii)
 96H  03/1800Z 18.5N 162.0W   40 KT  45 MPH - Tropical Storm (WSW Kōloa, Hawaii)
120H  04/1800Z 20.0N 165.0W   35 KT  40 MPH - Tropical Storm (WSW Kōloa, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 500 AM HST Tue Jul 30, 2019

The eye of the hurricane became much more distinct in infrared satellite imagery overnight, which indicates that rapid intensification has occurred. The latest intensity estimates from the satellite agencies are 5.0 (90 kt) from SAB, 5.5 (102 kt) from HFO, and 6.0 (115 kt) from JTWC. The CIMSS ADT estimate using the raw T number suggests the intensity is close to 100 kt. For this advisory, we are intensifying Erick to 100 kt, so it is now a major hurricane. Note that the initial wind radii for this advisory were adjusted based on a 0633Z ASCAT pass, which covered nearly the entire circulation of Erick.

The hurricane’s initial motion is 280/15 kt for this advisory. The mid-level ridge to the north is still forecast to weaken later today, which is expected to cause a slower forward motion toward the west-northwest. The track guidance now appears to have somewhat less spread. The latest ECMWF and its ensemble mean continue to be slightly faster than the rest of the models. For this advisory, we are more closely following the latest NOAA corrected consensus (HCCA) output. As a result, the track has been nudged slightly to the right of the previous forecast during the 12-48 hour time frame. After that, the latest track forecast follows the previous forecast during days 3-5.

The latest estimates for wind shear in the vicinity of Erick appear to be less than 10 kt from the west. In addition, sea surface temperatures remain close to 28C along the track for the next couple of days, and the CIRA Ocean Heat Content values show sufficient warm water at depth along the forecast track. Therefore, the environment around Erick will likely remain conducive for additional intensification during the next 12-24 hours. The current forecast closely follows the HCCA, as well as the consensus intensity forecast output, IVCN. Some gradual weakening is forecast to begin starting around 36 hours, and continuing through 48 hours. After that time, the circulation around a broad upper-level trough in the vicinity of the Hawaiian Islands will likely cause a significant increase in shear (at least 25 kt from the west) as Erick continues to move toward the west-northwest. Therefore, this advisory continues to show rapid weakening during the 2-3 day time frame. This weakening trend will likely persist during days 4 and 5.

FORECAST POSITIONS AND MAX WINDS

INIT  30/1500Z 13.4N 142.8W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 12H  31/0000Z 14.0N 144.6W  110 KT 125 MPH - Category 3 (WSW Hilo, Hawaii)
 24H  31/1200Z 14.8N 146.6W  110 KT 125 MPH - Category 3 (WSW Hilo, Hawaii)
 36H  01/0000Z 15.4N 148.6W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 48H  01/1200Z 15.9N 150.8W   90 KT 105 MPH - Category 2 (WSW Hilo, Hawaii)
 72H  02/1200Z 16.6N 155.8W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 96H  03/1200Z 17.5N 160.0W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  04/1200Z 19.0N 164.0W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 1100 PM HST Mon Jul 29 2019

Hurricane Erick  which is the first tropical cyclone to enter the central Pacific during the 2019 Hurricane Season, has been showing signs of an eye trying to emerge in conventional infrared satellite imagery this evening. Microwave images also continue to show evidence of an eye surrounded by a ring of deep convection. The latest intensity estimates from the satellite agencies are 4.0(65 kt) from SAB, 4.5(77 kt) from HFO, and 5.0(90 kt) from JTWC. The latest CIMSS ADT estimate is 3.9(63 kt). For this advisory, we are intensifying Erick slightly to 70 kt as a compromise, since the eye has not become clearly defined yet.

The hurricane’s short-term motion appears to be slightly slower than 6 hours ago, but the longer-term motion is 280/15 kt for this advisory. The mid-level ridge to the north is still forecast to weaken Tuesday, which is expected to cause a slower forward motion toward the west-northwest. The track guidance continues to have some spread. The latest ECMWF and its ensemble mean remain faster than the rest of the models. For this advisory, we have kept the track forecast similar to the previous package.

We continue to believe that the environment around Erick will remain conducive for additional intensification during the next 36-48 hours. The latest forecast again indicates Erick may attain major hurricane status during the next couple of days. The circulation around a broad upper-level trough in the vicinity of the Hawaiian Islands will likely cause a significant increase in shear as Erick continues to move toward the west-northwest beyond 48 hours. Therefore, this advisory continues to show rapid weakening during the 2 to 3 day time frame.

FORECAST POSITIONS AND MAX WINDS

INIT  30/0900Z 13.1N 141.4W   70 KT  80 MPH - Category 1 (WSW Hilo, Hawaii)
 12H  30/1800Z 13.5N 143.3W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 24H  31/0600Z 14.3N 145.6W   90 KT 105 MPH - Category 2 (WSW Hilo, Hawaii)
 36H  31/1800Z 14.9N 147.7W   95 KT 110 MPH - Category 2 (WSW Hilo, Hawaii)
 48H  01/0600Z 15.4N 149.8W   95 KT 110 MPH - Category 2 (WSW Hilo, Hawaii)
 72H  02/0600Z 16.2N 154.2W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 96H  03/0600Z 17.0N 158.5W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  04/0600Z 18.0N 162.5W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 1100 AM HST Mon Jul 29, 2019

An average of Dvorak intensity estimates indicates that Erick is not quite a hurricane yet. The cloud pattern has not changed very much since this morning, and the mid-level eye in microwave data has been intermittent. The initial intensity is kept at 60 kt in this advisory.

The environment continues to be favorable for intensification, and Erick is expected to become a hurricane soon. The corrected- consensus HCCA and the FSU Superensemble FSSE continue to bring Erick to near category 3 by 2 days, and so does the NHC forecast. By the end of the forecast period, when the cyclone is in the central Pacific region, it should encounter strong westerly shear and weakening should then begin. The official forecast does not depart significantly from the previous one.

Erick is moving toward the west-northwest or 285 degrees at 14 kt steered by the easterly flow around the subtropical ridge. The ridge is forecast to weaken slightly, and this pattern should provide a west-northwestward motion of the cyclone with a decrease in forward speed. There are no models suggesting any sharp turn to the north during the next 5 days. The NHC track forecast has changed little and is basically on top of the multi-model consensus TVCE and the corrected consensus HCCA.

FORECAST POSITIONS AND MAX WINDS

INIT  29/2100Z 12.7N 138.4W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  30/0600Z 13.2N 140.4W   70 KT  80 MPH - Category 1 (WSW Hilo, Hawaii)
 24H  30/1800Z 13.8N 143.1W   80 KT  90 MPH - Category 1 (WSW Hilo, Hawaii)
 36H  31/0600Z 14.6N 145.3W   90 KT 105 MPH - Category 2 (WSW Hilo, Hawaii)
 48H  31/1800Z 15.3N 147.3W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 72H  01/1800Z 16.0N 151.0W   75 KT  85 MPH - Category 1 (WSW Hilo, Hawaii)
 96H  02/1800Z 16.5N 156.0W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  03/1800Z 17.5N 160.0W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Mon Jul 29, 2019

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

The National Hurricane Center in Miami, Florida is issuing advisories on Tropical Storm Erick centered over 1250 miles east-southeast of Hilo, Hawaii. Erick is expected to intensify and move into the Central Pacific Hurricane Center area of responsibility as a hurricane tonight.

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, centered over 2600 miles east-southeast of Hilo, Hawaii. Flossie is expected to move into the Central Pacific Hurricane Center area of responsibility late Friday.

NWS National Hurricane Center Miami FL 500 AM HST Mon Jul 29, 2019

Conventional IR satellite images suggest that the cloud pattern has not changed significantly during the past several hours, and in fact, it appears that it has deteriorated some. However, recent microwave data reveal the development of an eye, and most likely this feature will soon become apparent on conventional imagery. Based on an average of both UW-CIMSS objective and subjective Dvorak numbers, the initial intensity is kept at 60 kt in this advisory.

The environment is currently favorable for intensification, and Erick is expected to become a hurricane at any time soon. The most aggressive intensity models are the corrected consensus HCCA and the FSU Superensemble FSSE which bring Erick to Cat 3 by 2 days, and so does the NHC forecast. By the end of the forecast period, when the cyclone is in the central Pacific region, it should encounter strong westerly shear and weakening should then begin. The official forecast does not depart from the previous one.

Erick is moving toward the west or 275 degrees at 15 kt. The cyclone is currently being steered by the easterly flow around the subtropical ridge. The ridge is forecast to weaken slightly, and this pattern should provide a west-northwest motion of the cyclone. In addition, there is no evidence of any sharp turn to the north in any of the track models. The NHC forecast remains unchanged and is basically on top of the multi-model consensus TVCE and the corrected consensus HCCA.

FORECAST POSITIONS AND MAX WINDS

INIT  29/1500Z 12.3N 136.9W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  30/0000Z 13.0N 139.1W   70 KT  80 MPH - Category 1 (WSW Hilo, Hawaii)
 24H  30/1200Z 13.6N 141.8W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 36H  31/0000Z 14.3N 144.1W   95 KT 110 MPH - Category 2 (WSW Hilo, Hawaii)
 48H  31/1200Z 15.0N 146.2W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 72H  01/1200Z 16.0N 150.5W   80 KT  90 MPH - Category 1 (WSW Hilo, Hawaii)
 96H  02/1200Z 16.8N 155.2W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  03/1200Z 17.5N 159.0W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 1100 PM HST Sun Jul 28, 2019

The storm’s cloud pattern is becoming better organized and has taken on a comma shape, with very cold cloud tops to at least -80 deg C. There is prominent upper-tropospheric outflow, except over the northeastern quadrant of the circulation. An eye is not yet evident in the imagery, however. Erick’s current intensity estimate is set at 60 kt in general agreement with objective Dvorak estimates from UW-CIMSS. The dynamical guidance indicates that the vertical shear will remain below 10 kt for the next 48 hours and SSTs should remain near 28 deg C, which would favor steady strengthening. Additionally, the SHIPS Rapid Intensification Index continues to show a high probability, near 70 percent, of rapid strengthening. Thus the official wind speed forecast shows a significant increase during the next 1 to 2 days, with the system predicted to attain major hurricane status within that time frame. This is in agreement with the corrected consensus, HCCA, and the FSU Superensemble guidance, FSSE, along with the HWRF model simulation.

Erick continues to move westward, or around 270/14 kt. A mid-level ridge is predicted to remain to the north of the tropical cyclone over the next several days which should maintain a mainly westward track. The track models suggest a slight bend toward the west-northwest in 36-72 hours, but with no substantial northward excursions. The new official track forecast is quite similar to the previous one, and is a little south of the latest dynamical model consensus. It should be noted that the latest ECMWF model run shows a track that is even a little farther to the south.

The wind radii have been adjusted based on data from a recent ASCAT-C overpass which depicted a slightly larger storm than previously estimated.

FORECAST POSITIONS AND MAX WINDS

INIT  29/0900Z 11.7N 134.5W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  29/1800Z 12.2N 136.7W   70 KT  80 MPH - Category 1 (WSW Hilo, Hawaii)
 24H  30/0600Z 12.8N 139.7W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 36H  30/1800Z 13.5N 142.3W   95 KT 110 MPH - Category 2 (WSW Hilo, Hawaii)
 48H  31/0600Z 14.1N 144.6W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 72H  01/0600Z 15.3N 148.9W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 96H  02/0600Z 16.0N 153.5W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  03/0600Z 16.9N 158.2W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 PM HST Sun Jul 28, 2019

There have been some significant changes with Erick during the past several hours. First, as foreshadowed in the previous advisory, microwave and scatterometer data indicate that the center has re-formed under a very strong convective cluster farther to the south. Second, the overall cloud pattern has become much better organized, with a CDO-like feature forming near the center and a notable increase in curved banding in the southern and western quadrants of the storm. Erick appears to be in the beginning stages of rapid intensification, and the intensity will be increased to 55 kt for this advisory based on a consensus of estimates from TAFB, SAB and the CIMSS ADT.

This is one of these rare forecasts where it is difficult to find a reason not to predict rapid intensification. Erick is expected to be in an environment of very low vertical wind shear and warm water during the next 48 hours. While earlier forecasts were concerned about mid-level dry air, the southward reformation will probably help insulate the storm from that influence, along with the very low shear limiting mixing. Although there is no low-level ring present yet in the latest 37 gHz microwave channel, this signal can be both before and/or concurrent with rapid strengthening. Notably, the SHIPS-rapid intensification index is showing about a 70 percent chance of both a 30-kt increase during the next 24 hours and a 55-kt rise in 48 hours. It’s pretty hard to ignore the signal from that model, considering these are values you might see a few times a year. In addition, dynamical models have also come up sharply from the previous cycle, and three typically reliable models now show Erick becoming a major hurricane. Thus, the new NHC intensity forecast is considerably higher than the previous one through 48 hours, at the upper-end of the guidance envelope, and just a little above the corrected-consensus models. The forecast after that time required little adjustment, as a combination of higher shear and dry air aloft should contribute to steady weakening by the end of the forecast period.

After accounting for the center re-formation, the initial motion estimate is 270/14 kt. A gradual turn to the west-northwest is forecast during the next couple of days as a ridge weakens to the north, then a turn back to the west is anticipated due to Erick weakening and the ridge slightly strengthening. Model guidance remains in very good agreement this evening, with no significant outlier solutions. While the new track forecast has been shifted southwest of the previous one, it is mostly due to the center re-formation, and the forecast continues to be close to the eastern Pacific model consensus TVCE.

FORECAST POSITIONS AND MAX WINDS

INIT  29/0300Z 11.7N 133.1W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  29/1200Z 11.9N 135.3W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
 24H  30/0000Z 12.5N 138.2W   80 KT  90 MPH - Category 1 (WSW Hilo, Hawaii)
 36H  30/1200Z 13.2N 141.0W   90 KT 105 MPH - Category 2 (WSW Hilo, Hawaii)
 48H  31/0000Z 13.9N 143.6W  100 KT 115 MPH - Category 3 (WSW Hilo, Hawaii)
 72H  01/0000Z 15.1N 147.9W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 96H  02/0000Z 16.0N 152.5W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  03/0000Z 16.5N 157.3W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 1100 AM PDT Sun Jul 28, 2019

Although Erick’s upper-level outflow has continued to improve, the overall convective pattern hasn’t changed much. The earlier increase in central convection has been waning somewhat in recent satellite imagery, and the low-level center remains displaced just north of the central convection. However, passive microwave imagery indicates that the center has made a slight west-southwestward jog, possibly due to reformation closer to the strongest convection. The initial intensity has been increased to 40 kt based on a blend of Dvorak satellite intensity estimates of T2.5/35 kt from TAFB and T3.0/45 kt from SAB. An 1807Z partial ASCAT-A scatterometer pass indicated a 36-kt vector in the northeastern quadrant, and allowing for some undersampling also supports the 40-kt initial intensity.

The initial motion estimate is 270/15 kt. It is possible that the initial position could be too far north, and a southward shift may be required on the next advisory. However, the general trend in the model guidance remains a westward motion for the next 24 hours or so, followed by a gradual turn toward the west-northwest as Erick moves into a slight weakness in the subtropical ridge. By 72 hours and beyond, the weakness is forecast to fill with the narrow ridge building westward across the Hawaiian Islands. This is expected to force Erick on a general westward to west-northwestward track through the remainder of the forecast period. On the forecast track, Erick is expected to cross into the Central Pacific basin Tuesday morning. The new NHC forecast track has again been shifted south of the previous advisory track, mainly due to the more southerly initial position, and lies down the center of the tightly packed guidance envelope and is close to a blend of the consensus track models HCCA, FSSE, and TVCN.

The aforementioned ASCAT-A pass indicated that Erick has maintained a small radius of maximum winds (RMW) of about 20 nmi. The small RMW, low vertical wind shear, and SSTs near 28 deg C continue to support at least steady strengthening for the next few days, and Erick is forecast to become a hurricane in 36 hours. Although rapid intensification (RI) remains a possibility owing to the small RMW and low shear, the recent pronounced dry mid-level intrusion into the inner-core region, along with mid-level shear undercutting the other favorable outflow pattern, is expected to hinder any RI for at least the next 24 hours. By 72 hours, strong westerly vertical wind shear is forecast to affect the cyclone, inducing a steady weakening trend through the 120-h period. The latest Navy COAMPS model has backed off slightly and is now forecasting Erick to become a high-end category-3 hurricane in about 72 hours. However, this scenario has again been disregarded due to the abundance of dry mid-level air expected to affect the cyclone. The official intensity forecast is similar to the previous NHC advisory, and closely follows the HCCA corrected consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT  28/2100Z 12.0N 131.3W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  29/0600Z 12.3N 133.5W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 24H  29/1800Z 12.8N 136.4W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  30/0600Z 13.5N 139.1W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
 48H  30/1800Z 14.1N 142.0W   75 KT  85 MPH - Category 1 (WSW Hilo, Hawaii)
 72H  31/1800Z 15.3N 146.4W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 96H  01/1800Z 16.2N 150.9W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)
120H  02/1800Z 16.8N 155.9W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS Central Pacific Hurricane Center Honolulu HI 800 AM HST Sun Jul 28, 2019

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

The National Hurricane Center in Miami, Florida is issuing advisories on Tropical Storm Erick, centered about 1700 miles east-southeast of Hilo, Hawaii.

Erick is expected to intensify, and move into the Central Pacific Hurricane Center Area of Responsibility as a hurricane early Tuesday morning.

NWS National Hurricane Center Miami FL 1100 PM HST Sat Jul 27, 2019

Erick’s cloud pattern has not changed much in organization over the past several hours, although there is slight evidence of increased convective banding over the southern semicircle of the circulation. Dvorak intensity estimates from both TAFB and SAB remain at 35 kt, so the advisory intensity is held at 35 kt for now. An upper-level anticyclone is established over the storm, and water temperatures are sufficiently warm for intensification. Apparently, Erick has not yet acquired a well-defined inner core but that is expected to occur rather soon.

Therefore, steady strengthening is likely to begin within the next 12 hours. Some of the dynamical intensity models along with the simple and corrected consensus aids show the system becoming a hurricane within 36 hours, so the official forecast has been increased from the earlier NHC predictions and is near or below the consensus through 72 hours. By days 4 to 5, increased shear and some drier air is likely to cause weakening.

The motion continues to be only slightly north of due west, or 280/14 kt. The steering scenario is fairly straightforward. A fairly well-defined mid-level ridge is forecast by the global models to remain established to the north of Erick throughout most of the forecast period. By the end of the forecast period, this ridge is likely to weaken, and this could cause a more northward motion to develop. By that time, however, the weakening cyclone should be steered more by the low-level easterly flow which should keep the motion on a generally westward or just north of westward heading. The official track forecast is similar to the previous one and close to the corrected dynamical model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  28/0900Z 12.1N 128.1W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  28/1800Z 12.4N 130.2W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 24H  29/0600Z 12.8N 133.0W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  29/1800Z 13.4N 135.9W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
 48H  30/0600Z 14.0N 138.5W   75 KT  85 MPH - Category 1 (WSW Hilo, Hawaii)
 72H  31/0600Z 15.4N 143.3W   85 KT 100 MPH - Category 2 (WSW Hilo, Hawaii)
 96H  01/0600Z 16.6N 148.0W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
120H  02/0600Z 17.0N 153.0W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 PM HST Sat Jul 27, 2019

An ASCAT-C scatterometer overpass this afternoon showed an area of 35-kt winds over the eastern semicircle of the system’s circulation, which led to upgrading the depression to Tropical Storm Erick in an update just after the previous official advisory was issued. The overall presentation of the cyclone has changed little over the past several hours, and the latest satellite intensity estimate averages from TAFB and UW-CIMSS support keeping the system at 35 kt for this advisory.

The motion of Erick is 280/15 kt, driven by strong mid-level ridging to the north of the cyclone. This ridging is forecast to persist to the north of the Erick, with only slight weakening expected later in the forecast period. This will result in motion just north of west with a slight decrease in forward speed in a few days. Model guidance is in very good agreement on the forecast track of Erick. The latest guidance runs shifted back northward slightly from their previous runs, and the latest official forecast was nudged only a little north to lie essentially in the middle of the tightly clustered track guidance.

Environmental conditions are favorable for Erick to intensify over the next 3 to 4 days, with the only current inhibiting factor is that the system lacks a well-defined inner core. How fast this inner core consolidates will be a key factor in the pace of intensification of Erick in the short term. Based on expectation that the inner core will consolidate, the NHC official intensity forecast has been increased through 96 hours to follow the trends in the intensity guidance. It should be noted that some of the more reliable dynamical guidance is suggesting that Erick could intensify more than indicated in this favorable environment. By about 96 hours, Erick should begin to weaken as it is expected to begin moving into an environment of increasing southwesterly shear, with SHIPS guidance indicating over 20 kt of shear by day 5. And, at this same time dry air surrounding the system may begin to entrain into the storm’s circulation.

FORECAST POSITIONS AND MAX WINDS

INIT  28/0300Z 11.9N 126.8W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 12H  28/1200Z 12.2N 129.0W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
 24H  29/0000Z 12.6N 131.8W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  29/1200Z 13.1N 134.4W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)
 48H  30/0000Z 13.7N 137.1W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
 72H  31/0000Z 15.0N 142.1W   75 KT  85 MPH - Category 1 (WSW Hilo, Hawaii)
 96H  01/0000Z 16.5N 146.5W   70 KT  80 MPH - Category 1 (WSW Hilo, Hawaii)
120H  02/0000Z 17.0N 151.0W   55 KT  65 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 1100 AM PDT Sat Jul 27, 2019

The depression has not changed in organization since earlier this morning. GOES-17 visible imagery suggests that the depression’s center is embedded within an elongated northeast-to-southwest oriented trough, yet the cyclone also has a central area of convection and some convective banding. The initial intensity remains 30 kt based on Dvorak estimates of T2.0 from TAFB and SAB. It should be noted that just-received ASCAT data suggests the possibility the system is at tropical storm strength, and if this is confirmed a Tropical Cyclone Update will be issued before the next advisory.

A strong mid-level high is centered over the U.S./Mexico border, with the flow on its southern periphery pushing the depression quickly westward with a motion of 280/16 kt. The ridging is not expected to break down much during the forecast period, thus the cyclone is expected to maintain a westward or west-northwestward motion through day 5, with perhaps some slowing of its forward speed. The track models are tightly clustered, although most of them lie south of the previous official forecast. The new forecast has therefore been adjusted southward, but it lies along the northern edge of the guidance envelope.Tropical Storm Erick Wind Speeds 1100 Hours July 26 2019

Vertical shear is expected to be low for at least the next 4 days, with sea surface temperatures ahead of the cyclone being generally between 27 and 29 degrees Celsius. Therefore, strengthening is anticipated, although the trend could be gradual in the short term while the cyclone attempts to form a more symmetric circulation. The updated NHC official intensity forecast lies close to the IVCN model consensus, bringing the system to tropical storm strength by tonight and then to hurricane strength on Tuesday. If the circulation becomes more well defined sooner, then the cyclone could strengthen a little more than indicated in the forecast, as suggested by the HWRF and HCCA models.

FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 11.6N 125.3W   30 KT  35 MPH - Tropical Depression (WSW Hilo, Hawaii)
 12H  28/0600Z 11.8N 127.5W   35 KT  40 MPH - Tropical Storm (WSW Hilo, Hawaii)
 24H  28/1800Z 12.2N 130.4W   40 KT  45 MPH - Tropical Storm (WSW Hilo, Hawaii)
 36H  29/0600Z 12.6N 133.0W   45 KT  50 MPH - Tropical Storm (WSW Hilo, Hawaii)
 48H  29/1800Z 13.2N 135.6W   50 KT  60 MPH - Tropical Storm (WSW Hilo, Hawaii)
 72H  30/1800Z 14.3N 140.9W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
 96H  31/1800Z 15.6N 145.7W   65 KT  75 MPH - Category 1 (WSW Hilo, Hawaii)
120H  01/1800Z 16.7N 150.0W   60 KT  70 MPH - Tropical Storm (WSW Hilo, Hawaii)

NWS National Hurricane Center Miami FL 500 AM PDT Sat Jul 27, 2019

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

1. Recent satellite-derived wind data indicate that the disturbance located about 1200 miles southwest of the southern tip of the Baja California peninsula is already producing tropical-storm-force winds in gusts while a low-level center appears to be forming. If it becomes apparent that a center has formed, advisories will be initiated later this morning. This system is expected to move westward to west-northwestward at 10 to 15 mph.

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

2. An area of low pressure accompanied by disturbed weather is located a few hundred miles south-southwest of the Gulf of Tehuantepec. The gradual development of this system is expected, and a tropical depression is likely to form early next week while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Fri Jul 26 2019

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

1. Shower activity associated with an area of disturbed weather located a little more than 1000 miles southwest of the southern tip of the Baja California peninsula is gradually becoming better organized. Environmental conditions are favorable for additional development, and a tropical depression or tropical storm is likely to form either late this weekend or early next week. This system is expected to move westward to west-northwestward at 10 to 15 mph.

* Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.

2. An area of low pressure accompanied by disturbed weather is located a few hundred miles south of the Gulf of Tehuantepec. The gradual development of this system is expected, and a tropical depression is likely to form next week while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Fri Jul 26 2019

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

1. Shower activity associated with an area of disturbed weather located a little more than 1000 miles southwest of the southern tip of the Baja California peninsula has become better organized since yesterday. Environmental conditions are favorable for additional development, and a tropical depression or tropical storm is likely to form by early next week. This system is expected to move westward to west-northwestward at 10 to 15 mph.

* Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high...80 percent.

2. An area of low pressure accompanied by disturbed weather is located a few hundred miles south of the Gulf of Tehuantepec. The gradual development of this system is expected, and a tropical depression is likely to form next week while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Fri Jul 26,  2019

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

1. Recent satellite imagery indicates that the area of disturbed weather associated with a tropical wave located a little more than 1000 miles southwest of the southern tip of the Baja California peninsula is beginning to show some signs of organization. Environmental conditions are favorable for additional development and a tropical depression or tropical storm is likely to form by early next week. This system is expected to move westward to west-northwestward at 10 to 15 mph.

* Formation chance through 48 hours…medium…50 percent. * Formation chance through 5 days…high…70 percent.

2. An area of low pressure accompanied by disturbed weather has formed a few hundred miles south of the Gulf of Tehuantepec. Some gradual development of this system is expected, and a tropical depression is likely to form next week while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Fri Jul 26, 2019

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

1. Shower activity associated with a tropical wave located about 1000 miles south-southwest of the southern tip of the Baja California peninsula has become a little more organized since yesterday. Although there are no signs of a surface circulation at this time, environmental conditions are forecast to become more conducive for development during the next few days, and a tropical depression could form early next week. The disturbance is expected to move westward to west-northwestward at 10 to 15 mph.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…medium...50 percent.

2. An area of low pressure is expected to form a few hundred miles south of the coast of southern Mexico early next week. Some gradual development of the low is expected thereafter, and a tropical depression could form while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Thu Jul 25, 2019

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

1. A tropical wave located about 1100 miles south-southwest of the southern tip of the Baja California peninsula is producing a broad area of cloudiness and disorganized showers. Upper-level winds are expected to become more conducive for development during the next few days, and a tropical depression could form early next week while the disturbance 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 a few hundred miles south of the coast of southern Mexico early next week. Some gradual development of the low is expected thereafter, and a tropical depression could form while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium...50 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Thu Jul 25, 2019

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

1. A tropical wave located about a thousand miles south-southwest of the southern tip of the Baja California peninsula is producing a broad area of cloudiness and disorganized showers. Upper-level winds are expected to become more conducive for development during the next few days, and a tropical depression could form early next week while the disturbance 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 a few hundred miles south of the coast of southern Mexico early next week. Some gradual development of the low is expected thereafter, and a tropical depression could form while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Thu Jul 25, 2019

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

The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Dalila, located several hundred miles west of the southern tip of the Baja California peninsula.

1. A tropical wave located about a thousand miles south-southwest of the southern tip of the Baja California peninsula is producing a broad area of cloudiness and disorganized showers. Upper-level winds are expected to become more conducive for development during the next few days, and a tropical depression could form early next week while the disturbance 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 a few hundred miles south of the coast of southern Mexico early next week. Some gradual development of the low is expected thereafter, and a tropical depression could form while the system moves generally westward at 15 to 20 mph.

* 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 Thu Jul 25, 2019

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

The National Hurricane Center is issuing advisories on Tropical Depression Dalila, located several hundred miles west of the southern tip of the Baja California peninsula.

1. A tropical wave located about a thousand miles south-southwest of the southern tip of the Baja California peninsula is producing a broad area of cloudiness and disorganized showers. Upper-level winds are expected to become more conducive for development during the next few days, and a tropical depression could form early next week while the disturbance 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 a few hundred miles south of the coast of southern Mexico early next week. Some gradual development of the low is expected thereafter, and a tropical depression could form while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Wed Jul 24 2019

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

The National Hurricane Center is issuing advisories on Tropical Depression Dalila, located several hundred miles west-southwest of the southern tip of the Baja California peninsula.

1. A tropical wave located about a thousand miles south-southwest of the southern tip of the Baja California peninsula is producing a broad area of cloudiness and disorganized showers. Upper-level winds are expected to become more conducive for development during the next few days, and a tropical depression could form over the weekend or early next week while the disturbance 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 a few hundred miles south of the coast of southern Mexico by the end of the week. Some gradual development of the low is expected thereafter, and a tropical depression could form by early next week while the system moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium...40 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Wed Jul 24, 2019

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

The National Hurricane Center is issuing advisories on Tropical Depression Dalila, located several hundred miles west-southwest of the southern tip of the Baja California peninsula.

1. A tropical wave located almost a thousand miles south of the southern tip of the Baja California peninsula continues to produce disorganized showers and cloudiness. Upper-level winds are expected to become more conducive for development of this system during the next few days, and a tropical depression could form over the weekend or early next week while the system moves westward to west-northwestward at 10 to 15 mph.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium...40 percent.

2. An area of low pressure is expected to form a few hundred miles south of the coast of southern Mexico by the end of the week. Environmental conditions are expected to support gradual
development of the system, and a tropical depression could form by early next week while it moves generally westward at 15 to 20 mph.

* 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 Wed Jul 24, 2019

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

The National Hurricane Center is issuing advisories on recently downgraded Tropical Depression Dalila, located several hundred miles
west-southwest of the southern tip of the Baja California peninsula.

1. A tropical wave located almost a thousand miles south of the southern tip of the Baja California peninsula continues to produce disorganized showers and cloudiness. Some gradual development of this system is possible later this week while the system moves westward at around 15 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

2. An area of low pressure is expected to form a few hundred miles south of the coast of southern Mexico by the end of the week. Environmental conditions are expected to support gradual
development of the system, and a tropical depression could form by early next week while it moves generally westward at 15 to 20 mph.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Tue Jul 23, 2019

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

1. Disorganized cloudiness and showers located over the northwestern Gulf of Mexico are associated with a frontal boundary. A non-tropical low could form along this boundary late Wednesday or Thursday, and environmental conditions could support some subtropical or tropical development late this week while the disturbance meanders near the northern Gulf Coast.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…20 percent

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