Tag Archives: Tropical Storm Nolo

Typhoon Koguma Intensifies to Equivalent of a Major Hurricane

Typhoon Koguma intensified to the equivalent of a major hurricane east of the Northern Marianas on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Koguma was located at latitude 20.5°N and longitude 153.5°E which put the center about 640 miles (1035 km) east-northeast of Saipan.  Koguma was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 961 mb.

Typhoon Koguma intensified to the equivalent of a major hurricane on Friday as it was completing an eyewall replacement cycle.  A new larger eye was forming at the center of Koguma’s circulation.  Bands of showers and thunderstorms were revolving around the center of Typhoon Koguma.  Storms near the center of Koguma generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

Even though Typhoon Koguma was completing an eyewall replacement cycle, the circulation around Koguma was still small for a typhoon over the Western North Pacific Ocean.  Winds to typhoon force extended out 45 miles (75 km) from the center of Koguma’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Typhoon Koguma.

The Hurricane Intensity Index (HII) for Typhoon Koguma is 20.6.  The Hurricane Size Index (HSI) is 16.2 and the Hurricane Wind Intensity Size Index (HWISI) is 36.8.  Typhoon Koguma is similar in size and intensity to Hurricane Delta when Delta hit Louisiana in 2020.

Typhoon Koguma will move through an environment that will be favorable for intensification during the next 24 hours.  Koguma will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southwestern part of an upper level ridge that is over the Central North Pacific Ocean.  The upper level ridge will produce southeasterly winds that will blow toward the top of Koguma’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Typhoon Koguma will intensify during the next 24 hours.

Typhoon Koguma will move around the southwestern part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Koguma toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Koguma will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nolo continued to weaken gradually far to the southeast of Japan.

At 11:00 a.m. EDT on Friday the center of Tropical Storm Nolo was located at latitude 29.7°N and longitude 147.6°E which put the center about 635 miles (1025 km) southeast of Tokyo, Japan.  Nolo was moving toward the northwest at 13 m.p.h. (21 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 991 mb.

Koguma Strengthens to a Typhoon

Former Tropical Storm Koguma strengthened to a typhoon over the Western North Pacific Ocean east of the Northern Marianas on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Koguma was located at latitude 18.4°N and longitude 157.1°E which put the center about 810 miles (1310 km) east-northeast of Saipan.  Koguma was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 980 mb.

Former Tropical Storm Koguma strengthened to a typhoon on Thursday.  The inner end of a rainband wrapped around the southern side of the center of Koguma’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Typhoon Koguma.  Storms near the center of Koguma 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 Koguma was fairly symmetrical.  Winds to typhoon force extended out 30 miles (50 km) from the center of Koguma’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Typhoon Koguma.

Typhoon Koguma will move through an environment that will be favorable for intensification during the next 24 hours.  Koguma will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southwestern part of an upper level ridge that is over the Central North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Koguma’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Typhoon Koguma will intensify during the next 24 hours.  Koguma could strengthen to the equivalent of a major hurricane during the weekend.

Typhoon Koguma will move around the southwestern part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Koguma toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Koguma will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nolo was weakening gradually far to the southeast of Japan.

At 5:00 p.m. EDT on Thursday the center of Tropical Storm Nolo was located at latitude 28.1°N and longitude 150.6°E which put the center about 855 miles (1380 km) east-southeast of Tokyo, Japan.  Nolo was moving toward the west-northwest at 17 m.p.h. (28 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 991 mb.

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.

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.

Tropical Storm Nolo Forms South of Hawaii

Tropical Storm Nolo formed over the Central North Pacific Ocean south of Hawaii on Wednesday afternoon.  A Hurricane Watch was issued for the Big Island of Hawaii.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Nolo was located at latitude 14.5°N and longitude 155.3°W which put the center about 310 miles (500 km) south of South Point, Hawaii.  Nolo was moving toward the west-northwest at 6 m.p.h. (10 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 1003 mb.

A Hurricane Watch is in effect for Hawaii County.

The circulation around former Tropical Depression Fifteen-E strengthened on Wednesday afternoon and the U.S. National Hurricane Center designated the system as Tropical Storm Nolo.

The circulation around Tropical Storm Nolo was large.  Thunderstorms were occurring in bands that curled round the northern and western sides of the center of Nolo’s circulation.  Bands in the southern and eastern side of Tropical Storm Nolo consisted primarily of showers and lower clouds.  Storms near the center of Nolo started to generate upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to begin to decrease.

The strongest winds were occurring in the northern side of Tropical Storm Nolo.  Winds to tropical storm force extended out 35 miles (55 km) in the northern half of Nolo’s circulation.  The winds in the southern side of Tropical Storm Nolo were blowing at less than tropical storm force.

Tropical Storm Nolo will move through an environment that will be somewhat 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 under the southeastern part of an upper level trough that is northwest of Hawaii.  The upper level trough will produce southwesterly winds that will blow toward the top of Nolo’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear probably will not be enough to prevent intensification.  Tropical Storm Nolo is likely to intensify gradually during the next 24 hours.

The upper level trough that is northwest of Hawaii will pull Tropical Storm Nolo slowly toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Nolo will move closer to the Big Island of Hawaii.