Tag Archives: Lisianski Island

Rachel Strengthens to a Major Hurricane

Leave a reply

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 Depression Forms East-southeast of Hawaii

Tropical Depression Two-C formed east-southeast of Hawaii on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Depression Two-C was located at latitude 11.9°N and longitude 143.1°W which put the center about 960 miles (1545 km) east-southeast of Hilo, Hawaii.  The tropical depression was moving toward the west-northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1006 mb.

A low pressure system over the Central North Pacific Ocean east-southeast of Hawaii strengthened on Thursday morning and the U.S. National Hurricane Center designated the system as Tropical Depression Two-C.

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

Tropical Depression Two-C will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  The tropical depression 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 Eastern and Central North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Tropical Depression Two-C.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification but the wind shear will probably not be enough to prevent intensification.  Tropical Depression Two-C is likely to intensify slowly during the next 24 hours.

Tropical Depression Two-C will move around the southern side of a high pressure system that is over the Central North Pacific Ocean.  The high pressure system will steer the tropical depression toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Depression Two-C will move closer to Hawaii.

Elsewhere over the Central Pacific Ocean, Hurricane Lala was nearing the Papahanaumokuakea Marine National Monument.  At 11:00 a.m. EDT on Thursday the center of Hurricane Lala was located at latitude 24.2°N and longitude 172.2°W which put the center about 175 miles (280 km) southeast of Lisianski Island.  Lala was moving toward the north-northwest at 9 m.p.h. (15 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 969 mb.

A Hurricane Warning is in effect for the Papahanaumokuakea Marine National Monument from Lisianski Island to Maro Reef.

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

Hurricane Lala Moves North

Hurricane Lala moved north toward the Papahanaumokuakea Marine National Monument on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Lala was located at latitude 22.2°N and longitude 171.0°W which put the center about 330 miles (530 km) southeast of Lisianski Island.  Lala was moving toward the north-northwest at 9 m.p.h. (15 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. (220 km/h).  The minimum surface pressure was 955 mb.

A Hurricane Warning is in effect for the Papahanaumokuakea Marine National Monument from Lisianski Island to Maro Reef.

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

Hurricane Lala maintained its intensity for much of Wednesday.  Lala was exhibiting signs of starting to weaken slowly on Wednesday afternoon.  An upper level trough that was south of the Aleutian Islands was producing southwesterly winds that were blowing toward the top of Lala’s circulation.  Those winds were causing the vertical wind shear to increase.  The increase in vertical wind shear was likely the cause of the weakening of Hurricane Lala.

There was still a small circular eye at the center of Hurricane Lala.  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 Hurricane Lala.  Storms near the core of Lala generated upper level divergence that pumped mass away from the hurricane.  The removal of mass in the upper levels was slightly less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure started to increase slowly on Wednesday afternoon.

The distribution of wind speeds in Hurricane Lala was still fairly symmetrical on Wednesday afternoon.  Winds to hurricane force extended out 30 miles (50 km) from the center of Lala’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Hurricane Lala.

The Hurricane Intensity Index (HII) for Hurricane Lala is 22.1.  The Hurricane Size Index (HSI) is 11.0 and the Hurricane Wind intensity Size Index (HWISI) is 33.1.  Hurricane Lala is similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Hurricane Lala will move through an environment that will become unfavorable for intensification during the next 24 hours.  Lala will move over water where the Sea Surface Temperatures are near 27°C.  However, the upper level trough that is south of Aleutian Islands will continue to cause the vertical wind shear to increase on Thursday.  Hurricane Lala will continue to weaken during the next 24 hours.

The upper level trough south of the Aleutian Islands will steer Hurricane Lala toward the north on Thursday.  On its anticipated track, Hurricane Lala will reach the Papahanaumokuakea Marine National Monument on Thursday night.

Hurricane Lala will bring strong winds and heavy rain to parts of the Papahanaumokuakea Marine National Monument.  The winds around Hurricane Lala will also cause high surf conditions.

Lala Rapidly Intensifies to a Major Hurricane

Hurricane Lala rapidly intensified to a major hurricane west of Hawaii on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Lala was located at latitude 20.7°N and longitude 168.9°W which put the center about 495 miles (795 km) southeast of Lisianski Island.  Lala was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 953 mb.

A Hurricane Warning is in effect for the Papahanaumokuakea Marine National Monument from Lisianski Island to Maro Reef

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

Hurricane Lala rapidly intensified to a major hurricane west of Hawaii on Tuesday.  A circular eye was present at the center of Lala’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 Hurricane Lala.  Storms near the core of Lala generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The circulation around Hurricane Lala became more symmetrical when Lala rapidly intensified on Tuesday.  Winds to hurricane force extended out 25 miles (40 km) from the center of Lala’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Hurricane Lala.

The Hurricane Intensity Index (HII) for Hurricane Lala is 23.6.  The Hurricane Size Index (HSI) is 8.8 and the Hurricane Wind intensity Size Index (HWISI) is 32.4.  Hurricane Lala is similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Hurricane Lala will move through an environment that will become unfavorable for intensification during the next 24 hours.  Lala will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the southern part of an upper level trough that is south of Aleutian Islands.  The upper level trough will produce southwesterly winds that will blow toward the top of Lala’s circulation.  Those winds will cause the vertical wind shear to increase on Wednesday.  Hurricane Lala is likely to start to weaken during the next 24 hours when the vertical wind shear increases.

The upper level trough south of the Aleutian Islands will start to steer Hurricane Lala toward the north on Wednesday.  On its anticipated track, Hurricane Lala will move toward the Papahanaumokuakea Marine National Monument.

Hurricane Lala will bring strong winds and heavy rain to parts of the Papahanaumokuakea Marine National Monument.  The winds around Hurricane Lala will also cause high surf conditions.

Lala Strengthens Back to a Hurricane

Former Tropical Storm Lala strengthened back to a hurricane on Monday night.  At 5:00 a.m. EDT on Tuesday the center of Hurricane Lala was located at latitude 20.4°N and longitude 166.1°W which put the center about 635 miles (1025 km) southeast of Lisianski Island.  Lala was moving toward the west at 10 m.p.h. (16 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. (130 km/h).  The minimum surface pressure was 985 mb.

Former Tropical Storm Lala strengthened back to a hurricane on Monday night.  A small circular eye was at the center of Lala’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 Hurricane Lala.  Storms near the core of Lala generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The circulation around Hurricane Lala was smaller than Lala was when it moved near the Hawaiian Islands.  Winds to hurricane force extended out 20 miles in the northern side of Lala’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Hurricane Lala.

Hurricane Lala will move through an environment that will be favorable for intensification during the next 24 hours.  Lala will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level ridge that is west of Hawaii.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  However, Hurricane Lala will continue to move into a region of drier air that is also west of Hawaii.  The drier air will inhibit intensification.  Hurricane Lala is likely to intensify during the next 24 hours despite the effects of the drier air.

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