Tropical Development Likely over Southwest Gulf of Mexico

A tropical depression or tropical storm is likely to develop over the southwestern Gulf of Mexico later this week.  The U.S. National Hurricane Center is indicating the probability is 70% that a tropical depression or a tropical storm will form over the southwestern Gulf of Mexico later this week.

A trough of low pressure is currently over the southwestern Gulf of Mexico in the lower levels of the atmosphere.

Scattered showers and thunderstorms are occurring in the trough of low pressure.  However, there is no well defined center of circulation in the trough of low pressure at the current time.

The trough of low pressure will be in an environment that will be favorable for the formation of a tropical depression or a tropical storm during the next few days.  The trough of low pressure will be over water where the Sea Surface Temperatures are near 30°C.  Ir will be under the western part of an upper level ridge that is over the Gulf of Mexico.  The upper level ridge will produce southerly winds that will blow across the top of the surface trough.  Those winds will cause some vertical wind wind shear.  The vertical wind shear will inhibit the formation of a tropical depression or a tropical storm, but the wind shear may not be enough to prevent that formation.

A center of circulation at the surface is likely to organize gradually over the southwestern Gulf of Mexico during the next few days.  The U.S. National Hurricane Center has tentatively tasked a reconnaissance mission to investigate the system on Wednesday afternoon, if necessary.

Hurricane Rachel Still South of Baja California

Hurricane Rachel was still spinning over the Eastern North Pacific Ocean south of Baja California on Sunday evening.  At 11:00 p.m. EDT on Sunday the center of Hurricane Rachel was located at latitude 20.2°N and longitude 114.8°W which put the center about 365 miles (590 km) west-southwest of the southern tip of Baja California.  Rachel was moving toward the west-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 967 mb.

Although Hurricane Rachel strengthened earlier on Sunday, Rachel appeared to be weakening again on Sunday.  Hurricane Rachel was moving into a large mass of drier air.  The drier air caused many of the thunderstorms in the northern side of Rachel’s circulation to dissipate.  Thunderstorms were still occurring in bands in the southern half of Hurricane Rachel.  Storms near the center of Rachel still generated upper level divergence that pumped mass away from the hurricane.  However, the removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure started to increase again.

The distribution of wind speeds in Hurricane Rachel was still fairly symmetrical on Sunday evening.  Winds to hurricane force extended out 40 miles (65 km) from the center of Rachel’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Hurricane Rachel.

Hurricane Rachel will move through an environment that will be unfavorable for intensification during the next 24 hours.  Rachel will move over water where the Sea Surface Temperatures are near 27°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  However, Rachel will continue to move through the mass of drier air.  Hurricane Rachel is likely to weaken on Monday because of the effects of the drier air.

Hurricane Rachel will move around the southern side of a high pressure system that is over the Eastern North Pacific Ocean.  The high pressure system will steer Rachel toward the west during the next 24 hours.  On its anticipated track, Hurricane Rachel will move farther away from Baja California.

Typhoon Choi-wan Passes East of Iwo To

Typhoon Choi-wan passed east of Iwo To on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Choi-wan was located at latitude 25.7°N and longitude 146.4°E which put the center about 325 miles (525 km) east of Iwo To.  Choi-wan was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 916 mb.

Typhoon Choi-wan intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Sunday.  An eyewall replacement cycle appeared to be starting in Typhoon Choi-wan.  A circular eye with a diameter of 20 miles (32 km) was at the center of Choi-wan’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  The inner end of a rainband wrapped around the existing eye and eyewall.  A larger outer eyewall appeared to be forming around the existing eye and eyewall.  Bands of showers and thunderstorms were revolving around the core of Typhoon Choi-wan.  Storms near the core of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Choi-wan was large.  Winds to typhoon force extended out 80 miles (130 km) from the center of Choi-wan’s circulation.  Winds to tropical storm force extended out 355 miles (575 km) from the center of Typhoon Choi-wan.

The Hurricane Intensity Index (HII) for Typhoon Choi-wan is 31.6.  The Hurricane Size Index (HSI) is 27.4 and the Hurricane Wind Intensity Size Index (HWISI) is 59.0.  Typhoon Choi-wan is similar in intensity to Hurricane Laura when Laura hit Southwest Louisiana in 2020.  Typhoon Choi-wan is much larger than Hurricane Laura was.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Even though Typhoon Choi-wan will move through a favorable environment, Choi-wan is likely to weaken during the next 24 hours because of the eyewall replacement cycle.

Typhoon Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Choi-wan will pass east of Japan during the next few days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Koguma formed north of Kwajalein and former Hurricane Nolo moved west of the International Date Line.  Nolo is now designated as Typhoon Nolo because it is over the Western North Pacific Ocean.

At 11:00 p.m. EDT on Sunday the center of Tropical Storm Koguma was located at latitude 10.8°N and longitude 168.0°E which put the center about 125 miles (200 km) north of Kwajalein. Koguma was moving toward the northeast at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1002 mb.

At 11:00 p.m. EDT on Sunday the center of Typhoon Nolo was located at latitude 25.0°N and longitude 178.6°W which put the center about 315 miles (510 km) southwest of Midway Island.  Nolo was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 955 mb.

Nolo Strengthens Back to a Major Hurricane

Hurricane Nolo strengthened back to a major hurricane as it moved over the Central North Pacific Ocean far to the west of Hawaii on Saturday.

At 11:00 p.m. EDT on Saturday the center of Hurricane Nolo was located at latitude 23.4°N and longitude 175.1°W which put the center about 200 miles (320 km) south-southwest of Lisianski Island.  Nolo was moving toward the west at 20 m.p.h. (32 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (215 km/h).  The minimum surface pressure was 957 mb.

Hurricane Nolo strengthened back to a major hurricane on Saturday.  However, Nolo appeared to be in the middle of an eyewall replacement cycle on Saturday night.  The inner end of a rainband wrapped around the existing eye and eyewall.  The eye was no longer seen on satellite images.  Bands of showers and thunderstorms were revolving around the core of Nolo’s circulation.  Storms near the core of Nolo generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease on Saturday.

The distribution of wind speeds in Hurricane Nolo was relatively symmetrical.  Winds to hurricane force extended out 30 miles (50 km) from the center of Nolo’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Hurricane Nolo.

The Hurricane Intensity Index (HII) for Hurricane Nolo is 20.6.  The Hurricane Size Index (HSI) is 11.6 and the Hurricane Wind Intensity Size Index (HWISI) is 32.2.  Hurricane Nolo is similar in size and intensity to Hurricane Delta when Delta hit Louisiana in 2020.

Hurricane Nolo will move through an environment favorable for intensification during the next 24 hours.  Nolo will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Nolo could weaken during the next few hours until the eyewall replacement cycle is completed.  Nolo is likely to intensify again after the eyewall replacement cycle is completed.

Hurricane Nolo will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nolo toward the west-northwest during the next 24 hours.  On its anticipated track, Hurricane Nolo will move across the International Date Line on Sunday.

Elsewhere, Hurricane Rachel continued to spin south of Baja California.

At 11:00 p.m. EDT on Saturday the center of Hurricane Rachel was located at latitude 20.0°N and longitude 112.8°W which put the center about 275 miles (440 km) southwest of the southern tip of Baja California.  Rachel was moving toward the west-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 970 mb.

Typhoon Choi-wan Intensifies to Equivalent of a Major Hurricane

Typhoon Choi-wan intensified to the equivalent of a major hurricane as it moved east-southeast of Iwo To on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Choi-wan was located at latitude 22.5°N and longitude 147.1°E which put the center about 410 miles (665 km) east-southeast of Iwo To.  Choi-wan was moving toward the north-northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 942 mb.

Typhoon Choi-wan intensified to the equivalent of a major hurricane on Saturday.  A circular eye with a diameter of 20 miles (32 km) was at the center of Choi-wan’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Choi-wan.  Storms near the core of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Choi-wan was large.  Winds to typhoon force extended out 90 miles (145 km) from the center of Choi-wan’s circulation.  Winds to tropical storm force extended out 355 miles (575 km) from the center of Typhoon Choi-wan.

The Hurricane Intensity Index (HII) for Typhoon Choi-wan is 23.6.  The Hurricane Size Index (HSI) is 28.8 and the Hurricane Wind Intensity Size Index (HWISI) is 52.4.  Typhoon Choi-wan is similar in size and intensity to Hurricane Wilma when Wilma hit South Florida in 2005.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan Choi-wan will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Choi-wan is likely to continue to  intensify during the next 24 hours unless an eyewall replacement cycle occurs.

Typhoon Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Choi-wan will pass east of Iwo To on Sunday.

Hurricane Rachel Spins South of Baja California

Hurricane Rachel was spinning over the Eastern North Pacific Ocean south of Baja California on Friday night.

At 11:00 p.m. EDT on Friday the center of Hurricane Rachel was located at latitude 19.4°N and longitude 111.5°W which put the center about 265 miles (425 km) south-southwest of the southern tip of Baja California.  Rachel was moving toward the west at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 966 mb.

Hurricane Rachel weakened gradually on Friday.  Rachel move over cooler water that was mixed to the surface by the passage of Hurricane Polo last week.  The cooler water caused some of the thunderstorms, especially on the northern side of Rachel’s circulation to weaken.

The circulation around Hurricane Rachel was still well organized even though Rachel was a little weaker than it was yesterday.  A circular eye was still present at the center of Rachel’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Thunderstorms were also occurring in bands in the southern half of Hurricane Rachel.  Bands in the northern side of Rachel’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Rachel generated less upper level divergence that pumped less mass away from the hurricane.  The removal of mass in he upper levels was less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure to increased on Friday.

The distribution of winds speeds in Hurricane Rachel was fairly symmetrical . Winds to hurricane force extended out 45 miles (75 km) from the center of Rachel’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Hurricane Rachel.

Hurricane Rachel will move through an environment unfavorable for intensification during the next 24 hours.  Rachel will move over water where the Sea Surface Temperatures are near 27°C. It will move under the southern side of an upper level ridge that is over Baja California.  The upper level ridge will produce northeasterly winds that will blow toward the top of Rachel’s circulation.  Those winds will cause moderate vertical wind shear.  Hurricane Rachel is likely to continue to weaken on Saturday because of the moderate vertical wind shear.

Hurricane Rachel will move around the southern part of a high pressure system that is over the Eastern North Pacific Ocean.  The high pressure system will steer Rachel toward the west during the next 24 hours.  On its anticipated track, Hurricane Rachel will continue to move farther away from Baja California.

Elsewhere, former Tropical Storm Nolo strengthened back to a hurricane far to the west of Hawaii.

At 11:00 p.m. EDT on Friday the center of Hurricane Nolo was located at latitude 23.4°N and longitude 168.5°W which put the center about 145 miles (230 km) west-southwest of French Frigate Shoals.  Nolo was moving toward the west at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 978 mb.

A Tropical Storm Warning is in effect for the Papahanaumokuakea Marine National Monument from French Frigate Shoals to Lisianaki Island including Maro Reef.

Choi-wan Strengthens to Typhoon West of Northern Marianas

Former Tropical Storm Choi-wan strengthened to a typhoon over the Western North Pacific Ocean west of the Northern Marianas on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Choi-wan was located at latitude 18.0°N and longitude 144.7°E which put the center about 80 miles (130 km) west of Alamagan.  Choi-wan was moving toward the north at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 981 mb.

A Typhoon Warning is in effect for Agrihan and Pagan.

A Tropical Storm Warning is in effect for Tinian, Saipan, and Alamagan.

A Typhoon Watch is in effect for Alamagan.

Former Tropical Storm Choi-wan strengthened to a typhoon on Friday.  The inner end of a rainband wrapped around the center of Typhoon Choi-wan.  Other bands of showers and thunderstorms were revolving around the center of Choi-wan’s circulation.  Storms near the center of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Typhoon Choi-wan was asymmetrical.  Winds to typhoon force extended out 110 miles (175 km) in the southern half of Choi-wan’s circulation.  Winds to tropical storm force extended out 50 miles (80 km) in the northern half of Typhoon Choi-wan.  Winds to tropical storm force extended out 250 miles (400 km) in the southern side of Typhoon Choi-wan.  Winds to tropical storm force extended out 175 miles (280 km) in the northern side of Choi-wan’s circulation.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan Choi-wan will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Choi-wan will intensify during the next 24 hours.  Choi-wan is likely to strengthen to the equivalent of a major hurricane during the weekend.

Tropical Storm Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Choi-wan will move away from the Northern Marianas during the weekend.

Tropical Storm Choi-wan will bring strong winds and heavy rain to Alamagan, Agrihan, Pagan, and Anataham.  Heavy rain could cause floods in some locations. Choi-wan could also bring gusty winds and heavy rain to Tinian and Saipan.  Bands in the southern periphery of Typhoon Choi-wan could drop heavy rain over Guam and Rota.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Rachel Strengthens to a Major Hurricane

Hurricane Rachel strengthened to a major hurricane over the Eastern North Pacific Ocean south of Baja California on Thursday afternoon.

At 5:00 p.m. EDT on Thursday the center of Hurricane Rachel was located at latitude 19.4°N and longitude 109.5°W which put the center about 245 miles (390 km) south of the southern tip of Baja California.  Rachel was moving toward the west at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 950 mb.

Hurricane Rachel intensified to a major hurricane on Thursday afternoon.  The inner end of a rainband wrapped around the center of Rachel’s circulation.  A circular eye with a diameter of 12 miles (19 km) was at the center of Rachel’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Rachel’s circulation.  Storms near the core of Rachel generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The distribution of winds speeds in Hurricane Rachel was fairly symmetrical.  Winds to hurricane force extended out 40 miles (65 km) from the center of Rachel’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Hurricane Rachel.

The Hurricane Intensity Index (HII) for Hurricane Rachel is 22.1.  The Hurricane Size Index (HSI) is 14.0 and the Hurricane Wind Intensity Size Index (HWISI) is 36.1.  Hurricane Rachel is similar in size and intensity to Hurricane Milton when Milton hit Florida in 2024.

Hurricane Rachel will move through an environment favorable for intensification during the next 24 hours.  Rachel will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Rachel will intensify during the next 24 hours.  Rachel will move over cooler water during the weekend.  Hurricane Rachel will start to weaken when it moves over the cooler water.

Hurricane Rachel will move around the western part of a high pressure system that is over the Eastern North Pacific Ocean.  The high pressure system will Rachel toward the west during the next 24 hours. On its anticipated track, Hurricane Rachel will gradually move farther away from Baja California.

Elsewhere, Tropical Storm Nolo started to intensify again far to the west of Hawaii.

At 5:00 a.m. EDT on Thursday the center of Tropical Storm Nolo was located at latitude 22.3°N and longitude 165.5°W which put the center about 120 miles (195 km) south-southeast of French Frigate Shoals.  Nolo was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 993 mb.

A Tropical Storm Warning is in effect for the Papahanaumokuakea Marine National Monument from Nihoa to Maro Reef including French Frigate Shoals.

A Tropical Storm Watch is in effect for the Papahanaumokuakea Marine National Monument from Maro Reef to Lisianski Island.

Tropical Storm Choi-wan Forms East of Northern Marianas

Tropical Storm Choi-wan formed over the Western North Pacific Ocean east of the Northern Marianas on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Choi-wan was located at latitude 16.3°N and longitude 149.5°E which put the center about 150 miles (240 km) east of Alamagan.  Choi-wan was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

A low pressure system over the Western North Pacific Ocean east of the Northern Marianas strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Choi-wan.

The distribution of thunderstorms in Tropical Storm Choi-wan was asymmetrical.  Thunderstorms were occurring in bands in the western side of Choi-wan’s circulation.  Bands in the eastern side of Tropical Storm Choi-wan consisted primarily of showers and lower clouds.  Storms near the center of Choi-wan generated upper level divergence that pumped mass away to the west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds in Tropical Storm Choi-wan were occurring in the bands of thunderstorms in the western side of Choi-wan.  Winds to tropical storm force extended out 115 miles (185 km) in the western half of Choi-wan’s circulation.  The winds in the eastern side of Tropical Storm Choi-wan were blowing at less than tropical storm force.

Tropical Storm Choi-wan will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Choi-wan will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is south of Japan.  The upper level ridge will produce easterly winds that will blow toward the top of Choi-wan’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Choi-wan will intensify during the next 24 hours.  Choi-wan could strengthen to a typhoon by the end of the week.

Tropical Storm Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Choi-wan will move over Alamagan, Agrihan, Pagan, and Anatahan on Thursday.

Tropical Storm Choi-wan will bring strong winds and heavy rain to Alamagan, Agrihan, Pagan, and Anataham.  Heavy rain could cause floods in some locations.  Choi-wan could also bring gusty winds and heavy rain to Tinian and Saipan.

A Flash Flood Watch is in effect for Tinian and Saipan.

A Tropical Storm Warning is in effect for Tinian and Saipan. 

A Tropical Storm Warning is in effect for Alamagan and Pagan.

A Typhoon Watch is in effect for Alamagan and Pagan.

A Tropical Storm Watch is in effect for Agrihan.

Rachel Intensifies to a Hurricane Southwest of Mexico

Former Tropical Storm Rachel intensified to a hurricane over the Eastern North Pacific Ocean southwest of Mexico on Tuesday night.

At 8:00 a.m. EDT on Wednesday the center of Hurricane Rachel was located at latitude 17.8°N and longitude 107.6°W which put the center about 220 miles (350 km) southwest of Cabo Corrientes, Mexico.   Rachel was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 979 mb.

A Tropical Storm Warning is in effect for the portion of the coast from Punta San Telmo to Playa, Perula, Mexico.

A Tropical Storm Watch is in effect for the portion of the coast from Playa Perula to Cabo Corrientes, Mexico.

Former Tropical Storm Rachel intensified to a hurricane on Tuesday night.  Tall thunderstorms formed near the center of Hurricane Rachel.  Bands of showers and thunderstorms were revolving around the center of Rachel’s circulation.  Storms near the center of Rachel generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the eastern side of Hurricane Rachel.  Winds to hurricane force extended out 25 miles (40 km) in the eastern side of Rachel’s circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center of Hurricane Rachel.

Hurricane Rachel will move through an environment that will be favorable for intensification during the next 24 hours.  Rachel will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Rachel will intensify during the next 24 hours.  Rachel could intensify rapidly at times.  Hurricane Rachel could strengthen to a major hurricane during the next day or so.

Hurricane Rachel will move around the western part of a high pressure system that is over northern Mexico.  The high pressure system will Rachel toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Rachel will move parallel to the coast of southwestern Mexico.

Bands in the eastern periphery will bring gusty winds and locally heavy rain to the coast of southwestern Mexico on Wednesday.  Heavy rain could cause flash floods in some locations.

Elsewhere, Former Hurricane Nolo weakened to a tropical storm far to the west of Hawaii.

At 8:00 a.m. EDT on Wednesday the center of Tropical Storm Nolo was located at latitude 22.2°N and longitude 164.8°W which put the center about 150 miles (240 km) southeast of French Frigate Shoals.  Nolo was moving toward the west at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 991 mb.

A Tropical Storm Warning is in effect for the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals.

A Tropical Storm Watch is in effect for the Papahanaumokuakea Marine National Monument from French Frigate Shoals to Maro Reef.