Tag Archives: Tropical Storm Karina

Tropical Storm Warning Issued for Kauai

Leave a reply

A Tropical Storm Warning has been issued for Kauai County because of the potential effects of Hurricane Lowell.  At 11:00 a.m. EDT on Sunday the center of Hurricane Lowell was located at latitude 14.7°N and longitude 163.8°W which put the center about 580 miles (935 km) south-southwest of Lihue, Hawaii.  Lowell was moving toward the north-northwest at 6 m.p.h. (10 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 943 mb.

A Tropical Storm Warning is in effect for Kauai County including Kauai and Niihau.

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

Hurricane Lowell weakened to Category 3 on the Saffir-Simpson Scale on Sunday morning.  Lowell was still a major hurricane.  A circular eye with a diameter of 30 miles (50 km) was still at the center of Lowell’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 Hurricane Lowell.  Storms near the center generated upper level divergence that pumped more mass away from the hurricane.  The removal of mass in the upper levels was nearly equal to the convergence of mass in the lowers levels of the atmosphere.  So, the surface pressure did not change much on Sunday morning.

The distribution of wind speeds in Hurricane Lowell was fairly symmetrical.  Winds to hurricane force extended out 50 miles (80 km) from the center of Lowell’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Hurricane Lowell.

The Hurricane Intensity Index (HII) for Hurricane Lowell is 23.6. The Hurricane Size Index (HSI) is 19.5 and the Hurricane Wind Intensity Size Index (HWISI) is 43.9.  Hurricane Lowell is bigger and stronger than Hurricane Milton was when Milton hit Florida in 2024.

Hurricane Lowell will move through an environment that will be less favorable for intensification during the next 24 hours.  Lowell 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 wind shear.  However, Lowell will  move into a mass of drier air that is southwest of Hawii.  Hurricane Lowell is likely to continue to weaken slowly because of the effects of the drier air.  Lowell will move southwest of an upper level low that is north of Hawaii on Monday.  The upper level low will produce southwesterly winds that will cause the vertical wind shear to increase.  The increase in vertical wind shear will cause Lowell to weaken faster on Monday.

Hurricane Lowell will move around the western end of a high pressure system that is over the Central North Pacific Ocean.  The high pressure system will steer Lowell toward the north during the next 24 hours.  On its anticipated track, the center of Hurricane Lowell will pass west of Kauai and Niihau on Monday night.

Bands in the eastern side of Lowell could bring strong winds and heavy rain to Kauai and Niihau on Monday night.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for Kauai and Niihau.

Bands in the eastern periphery of Hurricane Lowell could also drop heavy rain on Maui, Lanai, , Molokai, Oahu, the Big Island of Hawaii, and Kahoolawe.

Flood Watches are in effect for Maui, Lanai, Molokai, Oahu, the Big Island of Hawaii, and Kahoolawe.

Elsewhere, thunderstorms were decreasing Tropical Storm Karina and Hurricane Marie was weakening west of Baja California.

At 11:00 a.m. EDT on Sunday the center of Tropical Storm Karina was located at latitude 22.7°N and longitude 145.0°W which put the center about 680 miles (1100 km) east-northeast of Hilo, Hawaii.  Karina was moving toward the northwest at 7 m.p.h. (11 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 992 mb.

At 11:00 a.m. EDT on Sunday the center of Hurricane Marie was located at latitude 23.5°N and longitude 122.5°W which put the center about 800 miles (1290 km) west of the southern tip of Baja California.  Marie was moving toward the northwest 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 95 m.p.h. (150 km/h).  The minimum surface pressure was 977 mb.

 

Tropical Storm Watch Issued for Kauai

Leave a reply

A Tropical Storm Watch has been issued for Kauai County because of the potential effects of Hurricane Lowell.  At 11:00 p.m. EDT on Saturday the center of Hurricane Lowell was located at latitude 13.7°N and longitude 163.4°W which put the center about 630 miles (1015 km) south-southwest of Lihue, Hawaii.  Lowell was moving toward the west-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 942 mb.

A Tropical Storm Watch is in effect for Kauai County including Kauai and Niihau.

A Hurricane Watch is in effect for the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals.

Hurricane Lowell weakened to Category 4 on the Saffir-Simpson Scale on Saturday.  A circular eye with a diameter of 30 miles (50 km) was still at the center of Lowell’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 Hurricane Lowell.  Storms near the center generated upper level divergence that pumped more mass away from the hurricane.  The removal of mass in the upper levels was less than the convergence of mass in the lowers levels of the atmosphere.  So, the surface pressure increased on Saturday.

The distribution of wind speeds in Hurricane Lowell was fairly symmetrical.  Winds to hurricane force extended out 45 miles (75 km) from the center of Lowell’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Hurricane Lowell.

The Hurricane Intensity Index (HII) for Hurricane Lowell is 25.1.  The Hurricane Size Index (HSI) is 18.8 and the Hurricane Wind Intensity Size Index (HWISI) is 43.9. Hurricane Lowell is similar in intensity to Hurricane Harvey when Harvey hit Texas in 2017.  Hurricane Lowell is larger than Harvey was.

Hurricane Lowell will move through an environment that will be a little less favorable for intensification during the next 24 hours.  Lowell 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 wind shear.  However, Lowell will start to move into a mass of drier air on Sunday.  Hurricane Lowell is likely to continue to weaken slowly on Sunday because of the effects of the drier air.

Hurricane Lowell will move around the western end of a high pressure system that is over the Central North Pacific Ocean.  The high pressure system will steer Lowell toward the north during the next 24 hours.  On its anticipated track, Hurricane Lowell will start to move closer to Kauai and Niihau on Sunday.

Elsewhere, former Hurricane Karina weakened to a tropical storm east of Hawaii and Hurricane Marie started to weaken west of Baja California.

At 11:00 p.m. EDT on Saturday the center of Tropical Storm Karina was located at latitude 22.0°N and longitude 143.9°W which put the center about 740 miles (1190 km) east-northeast of Hilo, Hawaii.  Karina was moving toward the west-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.

At 11:00 p.m. EDT on Saturday the center of Hurricane Marie was located at latitude 22.6°N and longitude 121.3°W which put the center about 725 miles (1170 km) west of the southern tip of Baja California.  Marie was moving toward the northwest at 6 m.p.h. (10 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.

Tropical Storms Karina and Lowell Form over Eastern North Pacific

Tropical Storms Karina and Lowell formed over the Eastern North Pacific Ocean on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Karina was located at latitude 11.1°N and longitude 111.9°W which put the center about 825 miles (1330 km) south of the southern tip of Baja California.  Karina was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1001 mb.

Two low pressure systems over the Eastern North Pacific Ocean strengthened on Thursday afternoon and the U.S. National Hurricane Center designated the systems as Tropical Storm Karina and Tropical Storm Lowell.

Thunderstorms were developing in bands in the southern and eastern parts of Tropical Storm Karina.  Bands in the northwestern part of Karina’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Karina generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the northern part of Tropical Storm Karina.  Winds to tropical storm force extended out 205 miles (335 km) in the northern side of Karina’s circulation.  The winds in the southern side of Tropical Storm Karina were blowing at less than tropical storm force.

Tropical Storm Karina will move through an environment favorable for intensification during the next 24 hours.  Karina 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.  Tropical Storm Karina will intensify during the next 24 hours.  Karina could strengthen to a hurricane by Saturday morning.

Tropical Storm Karina will move around the southwestern part of a high pressure system that is centered over the Southwest U.S.  The high pressure system will steer Karina toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Karina will move far to the southwest of Baja California.

At 5:00 p.m. EDT on Thursday the center of Tropical Storm Lowell was located at latitude 11.3°N and longitude 133.8°W which put the center about 1765 miles (2840 km) west-southwest of the southern tip of Baja California.  Lowell was moving toward the east-northeast at 5 m.p.h. (8 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 1006 mb.

Tropical Storm Lowell is forecast to move west toward the Central North Pacific Ocean and to strengthen to a hurricane during the weekend.

Tropical Storm Karina Forms Southwest of Baja California

Tropical Storm Karina formed southwest of Baja California on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Karina was located at latitude 17.6°N and longitude 114.7°W which put it about 480 miles (775 km) southwest of the southern tip of Baja California.  Karina was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1001 mb.

More thunderstorms formed near the center of a low pressure system southwest of Baja California on Sunday and the National Hurricane Center designated the system as Tropical Storm Karina.  The distribution of thunderstorms around Tropical Storm Karina was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the southwestern part of Karina’s circulation.  Bands in other parts of the tropical storm consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence which pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 90 miles in the southwestern quadrant of Tropical Storm Karina.  Winds in other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Karina will move through an environment somewhat favorable for intensification during the next 24 hours.  Karina will move over water where the Sea Surface Temperature is near 28°C.  It will move south of an upper level ridge that extends from the southwestern U.S. over the Eastern North Pacific Ocean.  The ridge will produce northeasterly winds which will blow toward the top of Tropical Storm Karina.  Those winds will cause moderate vertical wind shear.  The shear will inhibit intensification, but it will not be strong enough to prevent Karina from intensifying.

Tropical Storm Karina will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Karina toward the west-northwest during the next several days.  On its anticipated track Tropical Storm Karina will move farther away from Baja California.

Tropical Storms Karina and Lowell and the Fujiwhara Effect

I am sometimes asked what happens when two tropical cyclones get close to each other.  The answer depends on the relative size and intensity of the two systems and how close they come to each other.  The Fujiwhara Effect is the name given to the tracks taken by the two vorticies.  If the two tropical cyclones are of nearly equal size and intensity, then they tend to move cyclonically around a center of rotation that is roughly half way between them.  If one cyclone is much bigger and stronger, then the center of rotation is shifted toward the bigger and stronger cyclone.

Tropical Storm Lowell has a large circulation and a maximum sustained wind speed of around 50 m.p.h.  Tropical Storm Karina is located about 700 miles to the west-southwest of Lowell.  Karina has a much smaller circulation and it also has a maximum sustained wind speed of 50 m.p.h.  Some of the models are forecasting that the two tropical storms will rotate around a point closer to Lowell than to Karina (i.e. the Fujiwara Effect).  This would result in Lowell moving general west-northwest and pass to the north of Karina.  The larger circulation of Lowell could also pull Karina back toward the east-northeast as Karina passes south of Lowell.  It is also possible that the circulation of Lowell could be so big that it captures Karina and Karina eventually gets absorbed by Lowell.