Tag Archives: HWISI

Hurricane Isaias Hits Northwest Florida

Hurricane Isaias hit Northwest Florida on Friday evening.  At 11:00 p.m. EDT on Friday the center of Hurricane Isaias was located at latitude 30.8°N and longitude 86.5°W which put the center about 45 miles (75 km) east-northeast of Pensacola, Florida.  Isaias was moving toward the north at 20 m.p.h. (32 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 982 mb.

A Hurricane Warning is in effect for the portion of the coast from the Mississippi/Alabama border to the Bay County/Gulf County line in Florida.

A Tropical Storm Warning is in effect for the portion of the coast from the Bay County/Gulf County line to the Aucilla River in Florida.

The center of Hurricane Isaias made landfall near Destin, Florida on Friday evening.

Hurricane Isaias was a Category 2 hurricane on the Saffir-Simpson Scale at the time of landfall.  The maximum sustained wind speed was 105 m.p.h. (165 km/h) when the center of Isaias made landfall.  The Hurricane Intensity Index (HII) was 17.8.  The Hurricane Size Index (HSI) was 14.6 and the Hurricane Wind Intensity Size Index (HWISI) was 32.4.

An upper level low that is over Mississippi will steer Hurricane Isaias toward the north during the next 24 hours.  On its anticipated track, Hurricane Isaias will move inland over Alabama on Saturday.

Hurricane Isaias will continue to bring strong winds to northwest Florida during the next few hours.  Even though Hurricane Isaias will weaken to a tropical storm by Saturday morning, Isaias will bring strong winds and heavy rain to Alabama on Saturday.

Flood Watches are in effect for parts of Alabama.

There are reports of over 400,000 customers without electricity in Florida.  There are also reports of over 200,000 customers without electricity in Alabama.

There are also reports of flooding due to a storm surge along parts of the coast of Northwest Florida.

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.

Isaias Intensifies to a Major Hurricane

Hurricane Isaias intensified to a major hurricane early on Friday as it moved toward the northern Gulf Coast.  At 8:20 a.m. EDT on Friday the center of Hurricane Isaias was located at latitude 27.0°N and longitude 87.6°W which put the center about 240 miles (390 km) south of Pensacola, Florida.  Isaias was moving toward the north-northeast at 15 m.p.h. (24 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 959 mb.

A Hurricane Warning is in effect for the portion of the coast from Ocean Springs, Mississippi to the Bay County/ Gulf County line in Florida.  The Hurricane Warning includes Mobile, Alabama and Pensacola, Florida.

A Tropical Storm Warning is in effect for the portion of the coast from the Jefferson Parish/Plaquemines Parish line in Louisiana to Ocean Springs, Mississippi.

A Tropical Storm Warning is in effect for the portion of the coast from the Bay County/Gulf County Line to Aucilla River, Florida.

Aircraft reconnaissance found that Hurricane Isaias had intensified to a major hurricane on Friday morning.

A circular eye with a diameter of 25 miles (40 km) was at the center of Hurricane Isaias.  Bands of showers and thunderstorms were revolving around the center of Isaias’ circulation.  Storms near the center of Isaias generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Hurricane Isaias increased on Thursday night.  Winds to hurricane force extended out 30 miles (50 km) from the center of Isaias’ circulation.  Winds to tropical storm force extended out 185 miles (295 km) from the center of Hurricane Isaias.

The Hurricane Intensity Index (HII) for Hurricane Isaias is 22.1.  The Hurricane Size Index (HSI) is 12.0 and the Hurricane Wind Intensity Size Index (HWISI) is 34.1.  Hurricane Isaias is similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Hurricane Isaias will move through an environment that will be somewhat favorable for intensification during the next 12 hours.  Isaias will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southeastern part of an upper level trough that is over Texas.  The upper level trough will produce southwesterly winds that will blow toward the top of Isaias’ circulation.  Those winds will cause moderate vertical wind shear, but the wind shear may not be enough to prevent intensification.  Hurricane Isaias could intensify during the next 12 hours.

The upper level trough over Texas will steer Isaias toward the north during the next 24 hours. On its anticipated track, Isaias will make landfall on the northern Gulf Coast near Pensacola, Florida on Friday night.

Hurricane Isaias will bring strong winds and locally heavy rain to the northern Gulf Coast.  Heavy rain could cause flash floods in some locations.  Isaias will be capable of causing major damage.  Widespread electricity outages are likely.

Flood Watches are in effect for parts of southern Mississippi, southern Alabama, and Northwest Florida.

Isaias could cause a storm surge of up to 13 feet (4 meters) along portions of the northern Gulf Coast.

A Storm Surge Warning is in effect for the portion of the coast from the Mouth of the Mississippi River to Suwannee River, Florida.

Hurricane Isaias Intensifies to Cat. 2

Hurricane Isaias intensified to Category 2 on the Saffir-Simpson Scale on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Hurricane Isaias was located at latitude 24.4°N and longitude 89.3°W which put the center about 325 miles (525 km) south of the Mouth of the Mississippi River.  Isaias was moving toward the northeast at 12 m.p.h. (19 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 975 mb.

A Hurricane Warning is in effect for the portion of the coast from Ocean Springs, Mississippi to the Bay County/ Gulf County line in Florida.  The Hurricane Warning includes Mobile, Alabama and Pensacola, Florida.

A Tropical Storm Warning is in effect for the portion of the coast from the Jefferson Parish/Plaquemines Parish line in Louisiana to Ocean Springs, Mississippi.

A Tropical Storm Warning is in effect for the portion of the coast from the Bay County/Gulf County Line to Aucilla River, Florida.

Hurricane Isaias intensified to Cat. 2 on the Saffir- Simpson Scale on Thursday afternoon.

The inner end of a rainband wrapped around the center of Isaias’ circulation.  A circular eye with a diameter of 30 miles (50 km) formed at the center of Hurricane Isaias.  Bands of showers and thunderstorms were revolving around the center of Isaias’ circulation.  Storms near the center of Isaias generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Hurricane Isaias became more symmetrical on Thursday afternoon.  Winds to hurricane force extended out 20 miles (30 km) from the center of Isaias’ circulation.  Winds to tropical storm force extended out 130 miles (210 km) from the center of Hurricane Isaias.

The Hurricane Intensity Index (HII) for Hurricane Isaias is 16.5.  The Hurricane Size Index (HSI) is 8.6 and the Hurricane Wind Intensity Size Index (HWISI) is 25.1.  Hurricane Isaias is similar in size and intensity to Hurricane Idalia when Idalia hit Florida in 2023.

Hurricane Isaias will move through an environment that will be favorable for intensification during the next 18 hours.  Isaias will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southeastern part of an upper level trough that is over the South Central U.S.  The upper level trough will produce westerly winds that will blow toward the top of Isaias’ circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Hurricane Isaias is likely to intensify during the next 18 hours.  Isaias could strengthen to a major hurricane.

Hurricane Isaias will move around the southeastern part of the upper level trough that is over the South Central U.S.   The upper level trough will steer Isaias toward the north-northeast during the next 24 hours.  On its anticipated track, Isaias will reach the northern Gulf Coast on Friday night.

Hurricane Isaias will bring strong winds and locally heavy rain to the northern Gulf Coast.  Heavy rain could cause flash floods in some locations.  Isaias will be capable of causing serious damage.  Widespread electricity outages are likely.

Flood Watches are in effect for parts of southern Mississippi, southern Alabama, and Northwest Florida.

Isaias could cause a storm surge of up to 12 feet (3.6 meters) along portions of the northern Gulf Coast.

A Storm Surge Warning is in effect for the portion of the coast from the Mouth of the Mississippi River to Suwannee River, Florida.

Typhoon Nolo Moves Northeast of Wake Island

Typhoon Nolo moved northeast of Wake Island on Monday evening.  At 11:00 p.m. EDT on Monday the center of Typhoon Nolo was located at latitude 25.7°N and longitude 172.0°E which put the center about 600 miles (970 km) northeast of Wake Island.  Nolo was moving toward the west at 17 m.p.h. (28 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.

Typhoon Nolo did not change much on Monday.  A circular eye with a diameter of 30 miles (50 km) was at the center of Nolo’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 center of Typhoon Nolo.  Storms near the center of Nolo generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels was nearly equal to the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure did not change much on Monday.

The distribution of wind speeds around Typhoon Nolo was fairly symmetrical.  Winds to typhoon force extended out 50 miles (80 km) from the center of Nolo’s circulation.  Winds to tropical storm force extended out 155 miles (250 km) from the center of Typhoon Nolo.

The Hurricane Intensity Index (HII) for Typhoon Nolo is 22.1.  The Hurricane Size Index (HSI) is 16.1 and the Hurricane Wind Intensity Size Index (HWISI) is 38.2.  Typhoon Nolo is similar in size and intensity to Hurricane Milton, when Milton hit Florida in 2024.

Typhoon Nolo will move through an environment that will be somewhat unfavorable 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 southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce northeasterly winds that will blow toward the top of Nolo’s circulation.  Those winds will cause moderate vertical wind shear.  Typhoon Nolo is likely to weaken gradually on Tuesday because of the moderate vertical wind shear.

Typhoon 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 during the next 24 hours.  On its anticipated track, Typhoon Nolo will pass north of Wake Island on Tuesday.

Elsewhere over the Western North Pacific Ocean, Typhoon Choi-wan weakened gradually northeast of Iwo To and Tropical Storm Koguma strengthened slowly north of Kwajalein.

At 11:00 p.m. EDT on Monday the center of Typhoon Choi-wan was located at latitude 30.8°N and longitude 146.3°E which put the center about 440 miles (710 km) northeast of Iwo To.  Choi-wan was moving toward the north at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 945 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Koguma was located at latitude 13.2°N and longitude 166.7°E which put the center about 295 miles (475 km) north of Kwajalein. Koguma was moving toward the northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 995 mb.

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.

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.

Hurricane Polo Brings Wind and Rain to Baja California

Hurricane Polo brought wind and rain to the southern part of Baja California on Monday night.

At 11:00 p.m. EDT on Monday the center of Hurricane Polo was located at latitude 25.9°N and longitude 112.5°W which put the center about 75 miles (120 km) north of Cabo San Lazaro, Mexico.  Polo was moving toward the northeast at 13 m.p.h. (21 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 963 mb.

A Hurricane Warning is in effect for the portion of the west coast of Baja California from Punta Abreojos to Santa Fe, Mexico.

A Hurricane Warning is in effect for the portion of the east coast of Baja California from  Loreto to Bahia San Juan Bautista, Mexico.

A Hurricane Warning is in effect for the portion of the coast from Bahia Kino to Huatabampito, Mexico.

A Tropical Storm Warning and a Hurricane Watch is in effect for the portion of the coast from Punta Eugenia to Punta Abreojos, Mexico.

A Tropical Storm Warning and a Hurricane Watch is in effect for the portion of the coast from ; Loreto to San Evaristo, Mexico.

A Tropical Storm Warning and a Hurricane Watch is in effect for the portion of the coast from Huatabampito to Topolobampo, Mexico.

Hurricane Polo was still a major hurricane on Monday night.  Winds to hurricane force extended out 40 miles (65 km) from the center of Polo’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Hurricane Polo.

he Hurricane Intensify Index (HII) for Hurricane Polo is 20.6.  The Hurricane Size Index (HSI) is 13.3 and the Hurricane Wind Intensity Size Index (HWISI) is 33.9.  Hurricane Polo is similar in size and intensity to Hurricane Zeta when Zeta hit Louisiana in 2020.

An upper level trough over the western U.S. will steer Hurricane Polo toward the northeast during the next 24 hours.  On its anticipate track, the center of Hurricane Polo will move across the southern part of Baja California during the next few hours.  The center of Polo’s circulation could pass between Loreto and Santa Rosalia.

Hurricane Polo will bring strong winds and heavy rain to southern Baja California. Heavy rain is likely to cause flash floods in some locations.  Hurricane Polo will be capable of causing major damage.

Hurricane Polo will weaken as it moves across the southern part of Baja California.  However, Polo could still be a hurricane when it reaches the west coast of Mexico.  The center of Hurricane Polo will make a landfall on the west coast of Mexico near Guaymas early on Tuesday.

Hurricane Polo will also bring strong winds and locally heavy rain to parts of Sonora.  Heavy rain is likely to cause flash floods in some locations there as well.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Rachel was strengthening gradually.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Rachel was located at latitude 14.3°N and longitude 102.5°W which put the center about 345 miles (555 km) south-southeast of Manzanillo, Mexico.   Rachel was moving toward the west-northwest at 10 m.p.h. (16 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 997 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.