Tag Archives: Hawaii

Tropical Storm Barbara Forms South of Baja California

Tropical Storm Barbara formed south of Baja California on Sunday as the remnants of former Hurricane Alvin were dissipating over the Eastern North Pacific Ocean.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Barbara was located at latitude 10.6°N and longitude 110.4°W which put it about 850 miles (1370 km) south of the southern tip of Baja California.  Barbara was moving toward the west-northwest at 16 m.p.h. (26 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.

More thunderstorms developed near the center of a low pressure system south of Baja California on Sunday and the National Hurricane Center designated the system as Tropical Storm Barbara.  Bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.  Tropical Storm Barbara was larger than former Hurricane Alvin.  Winds to tropical storms force extended out about 80 miles (130 km) from the center of circulation.

Tropical Storm Barbara will move through an environment favorable for intensification during the next several days.  Barbara will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Barbara will continue to intensify and it is likely to strengthen into a hurricane by the middle of the week.  Barbara could intensify rapidly when the inner core is more developed.

Tropical Storm Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara toward the west-northwest.  On its anticipated track Tropical Storm Barbara will move away from Baja California and the rest of Mexico.

Alvin Strengthens Into a Hurricane Southwest of Baja California

Former Tropical Storm Alvin strengthened into a hurricane southwest of Baja California on Thursday evening.  At 11:00 p.m. EDT on Thursday the center of Hurricane Alvin was located at latitude 17.4°N and longitude 115.4°W which put it about 520 miles (840 km) southwest of the southern tip of Baja California.  Alvin was moving toward the northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 992 mb.

The circulation around Hurricane Alvin exhibited much greater organization on Wednesday.  A small circular eye with a diameter of 10 miles (15 km) appeared at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  The circulation around Hurricane Alvin was very small.  Winds to hurricane force extended out only 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extended out about 50 miles (80 km) from the center.

Hurricane Alvin may be near its maximum intensity.  Alvin was moving over water where the Sea Surface Temperature was near 27°C.  However, it will move over cooler water on Friday.  The small size of the circulation around Hurricane Alvin could allow it to weaken quickly once it moves over the cooler water.

Hurricane Alvin will move near the western end of a subtropical ridge over Eastern North Pacific Ocean.  The ridge will steer Alvin toward the west-northwest during the next several days.  On its anticipated track Hurricane Alvin is forecast to weaken when it moves over colder water between Baja California and Hawaii.

Tropical Storm Alvin Develops South of Baja California

Tropical Storm Alvin developed south of Baja California on Wednesday morning, when former Tropical Depression One-E strengthened to a tropical storm.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Alvin was located at latitude 14.7°N and longitude 109.4°W which put it about 565 miles (915 km) south of the southern tip of Baja California.  Alvin was moving toward the west at 14 m.p.h. (22 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 1005 mb.

The circulation around Tropical Storm Alvin exhibited greater organization on Wednesday morning.  A band of thunderstorms wrapped around the eastern side of the center of circulation.  Other bands of showers and thunderstorms were organizing in the eastern half of the circulation.  Winds to tropical storm force extended out about 35 miles (55 km) from the center on the eastern side of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Alvin will move through an environment favorable for intensification during the next 24 to 36 hours.  Alvin will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Alvin will move south of an upper level ridge.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Storm Alvin will intensify during the next day or two and it could strengthen into a hurricane.

The upper level ridge will steer Tropical Storm Alvin toward the west during the next several days.  Alvin could move a little to the south of due west during the next 24 hours.  On its anticipated track Tropical Storm Alvin will move steadily farther away from Mexico.

Tropical Depression One-E Forms West of Mexico

Tropical Depression One-E formed west of Mexico on Tuesday afternoon.  More thunderstorms developed close to the center of a low pressure system over the Eastern North Pacific Ocean and the National Hurricane Center designated the system as Tropical Depression One-E.  At 5:00 p.m. EDT on Tuesday the center of Tropical Depression One-E was located at latitude 15.2°N and longitude 105.7°W which put it about 280 miles (450 km) south-southwest of Manzanillo, Mexico.  The depression was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1007 mb.

The circulation around Tropical Depression One-E exhibited greater organization on Tuesday afternoon.  Several short bands of showers and thunderstorms were developing near the center of circulation.  One band was north of the center, another was west of the center and a third band was south of the center of circulation.  Bands east of the center consisted primarily of showers and lower clouds.  Thunderstorms near the center of circulation were beginning to generate upper level divergence which was pumping mass away from the tropical depression.

Tropical Depression One-E will move through an environment favorable for intensification during the next day or two.  The depression will move over water where the Sea Surface Temperature is near 28°C.  It will move south of an upper level ridge over Mexico and the Eastern North Pacific Ocean.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear which will slow the rate of intensification, but the shear will not be strong enough to prevent intensification.  Tropical Depression One-E is likely to intensify into a tropical storm during the next 24 to 36 hours.

A subtropical ridge north of Tropical Depression One-E will steer the depression toward the west-northwest.  On its anticipated track Tropical Depression One-E will move away from Mexico.  It is forecast to pass south of Baja California.

Major Hurricane Sergio Churns Southwest of Baja California

Major Hurricane Sergio churned southwest of Baja California.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Sergio was located at latitude 13.3°N and longitude 117.9°W which put it about 845 miles (1360 km) southwest of the southern tip of Baja California.  Sergio was moving toward the 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 145 m.p.h. (230 km/h).  The minimum surface pressure was 955 mb.

Hurricane Sergio is a well organized hurricane.  There is a circular eye at the center of circulation.  A ring of strong thunderstorms surrounds the eye and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Hurricane Sergio.  Storms near the core are generating strong upper level divergence which is pumping mass away in all directions from the hurricane.

Winds to hurricane force extend out about 45 miles (75 km) from the center of Hurricane Sergio.  Winds to tropical storm force extend out about 150 miles (240 km) from the center of circulation.  The Hurricane intensity Index (HII) for Hurricane Sergio is 23.6.  The Hurrricane Size Index (HSI) is 15.1 and the Hurricane Wind Intensity Size Index (HWISI) is 38.7.

Hurricane Sergio will remain in an environment capable of supporting a major hurricane for several more days.  Sergio will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Sergio could strengthen to Category 4 on the Saffir-Simpson Scale.  Hurricane Sergio will move over cooler water in a couple of days and it is likely to weaken when that occurs.

Hurricane Sergio will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Sergio toward the northwest during the next day or so.  The ridge is forecast to strengthen on Friday and it will steer Sergio more toward the west when that happens.  On its expected track Hurricane Sergio will move gradually farther away from Baja California.

Hurricane Walaka Rapidly Intensifies to Category 5

Hurricane Walaka rapidly intensified to Category 5 on the Saffir-Simpson Scale on Monday.  At 11:00 p.m. EDT on Monday the center of Hurricane Walaka was located at latitude 13.2°N and longitude 169.8°W which put it about 240 miles (390 km) south of Johnston Atoll.  Walaka was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 920 mb.

A Hurricane Warning is in effect for Johnston Atoll.  A Hurricane Watch is in effect for the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals to Maro Reef.

The circulation of Hurricane Walaka is very well organized,  There is a circular eye at the center of Walaka.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Walaka.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.

Winds to hurricane force extended out about 50 miles (80 km) from the center of Hurricane Walaka.  Winds to tropical storm force extended out about 185 miles (300 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Walaka was 35.0.  The Hurricane Size Index (HSI) was 16.4 and the Hurricane Wind Intensity Size Index (HWISI) was 51.4.

Hurricane Walaka will remain in an environment very favorable for strong hurricanes for several more days.  Walaka will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Hurricane Walaka to weaken.  In several days Walaka will move into an area where the upper level winds are stronger and the vertical wind shear will increase.  Hurricane Walaka will weaken more quickly when the shear increases.

Hurricane Walaka is moving around the western end of a subtropical high pressure system.  The high pressure system will steer Walaka toward the north during the next several days.  On its anticipated track Hurricane Walaka will pass near Johnston Atoll on Tuesday.

Tropical Storm Walaka Forms South of Hawaii

Tropical Storm Walaka formed south of Hawaii on Saturday afternoon.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Walaka was located at latitude 11.5°N and longitude 159.1°W which put it about 680 miles (1095 km) south of Honolulu, Hawaii.  Walaka was moving toward the west at 15 m.p.h. (24 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 1005 mb.

A distinct low level center of circulation formed within an area of thunderstorms south of Hawaii on Saturday and the Central Pacific Hurricane Center designated the system as Tropical Storm Walaka.  The circulation around Walaka was still organizing.  Most of the thunderstorms were developing in bands south and east of the center of circulation.  Bands north and west of the center consisted primarily of showers and lower clouds.  Storms south and east of the center were beginning to generate upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Walaka will be moving through an environment that will be favorable for intensification.  Walaka will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Walaka will strengthen into a hurricane and it could intensify rapidly once the inner core is well organized around an eye.

Tropical Storm Walaka will move south of a subtropical high pressure system over the Central Pacific Ocean during the next two or three days.  The ridge will steer Walaka in a general westward direction.  On its anticipated track Tropical Storm Walaka will remain south of Hawaii.

Tropical Storm Olivia Nears Hawaii

Tropical Storm Olivia moved closer to Hawaii on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Olivia was located at latitude 21.6°N and longitude 152.3°W which put it about 275 miles (440 km) east of Kahului, Hawaii.  Olivia was moving toward the west 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 1000 mb.

Tropical Storm Warnings were in effect for Oahu, Hawaii County, Maui County including Maui, Molokai, Lanai and Kahoolawe, and for Kauai County including Kauai and Niihau.

Tropical Storm Olivia was weakening as it neared Hawaii.  An upper level trough north of Hawaii was producing strong westerly winds which were blowing across the top of the circulation.  Those winds caused significant vertical wind shear and they blew the tops off thunderstorms near the center of circulations.  Bands near the center and in the western half of Tropical Storm Olivia consisted primarily of showers and lower clouds.  There were still a few taller thunderstorms in bands on the far eastern side of the circulation.

Since Tropical Storm Olivia consisted mostly of a circulation in the lower levels of the atmosphere, it was being steered by the winds in the lower levels.  Olivia was moving south of the subtropical high over the central Pacific Ocean.  That high steered Tropical Storm Olivia quickly to the west on Tuesday and it will continue to do so.  On its anticipated track Tropical Storm Olivia will reach Hawaii on Wednesday.  Olivia will bring some gusty winds and it could drop locally heavy rain, especially where the wind rises over hills and mountains.

Hurricane Olivia Causes Tropical Storm Watches for Hawaii

The potential impacts of Hurricane Olivia caused the issuance of Tropical Storm Watches for Hawaii on Sunday night.  Tropical Storm Watches were issued for Oahu, Maui County including Maui, Molokai, Lanai, and Kahoolawe, and Hawaii County.  At 11:00 p.m. EDT on Sunday the center of Hurricane Olivia was located at latitude 21.4°N and longitude 146.1°W which put it about 595 miles (960 km) east-northeast of Hilo, Hawaii.  Olivia was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 988 mb.

Hurricane Olivia maintained its intensity and structure on Sunday.  A circular eye persisted at the center of circulation and a ring of thunderstorms surrounded the eye.  The strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Olivia.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (200 km) from the center.

Hurricane Olivia will move through a less favorable environment during the next several days.  Olivia will move over water where the Sea Surface Temperature is near 26°C.  So, there will be enough energy in the upper ocean to support a hurricane.  However, an upper level trough north of Hawaii will produce southwesterly winds which will blow toward the top of Hurricane Olivia.  Those winds will cause more vertical wind shear and Hurricane Olivia could weaken to a tropical storm as it approaches Hawaii.

Hurricane Olivia will move south of a subtropical high pressure system over the Central Pacific Ocean.  The high is forecast to strengthen and it will steer Olivia on a west-southwesterly track.  On its anticipated track Olivia could approach Hawaii late on Tuesday.  Olivia will bring gusty winds and it could cause power outages.  Locally heavy rain and the potential for flash floods are greater risks.

Hurricane Olivia Churns Toward Hawaii

Hurricane Olivia churned toward Hawaii on Saturday.  At 11:00 a.m. EDT on Saturday the center of Hurricane Olivia was located at latitude 21.4°N and longitude 138.0°W which put it about 1110 miles (1790 km) east of Hilo, Hawaii.  Olivia was moving toward the west at 15 m.p.h. (24 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 983 mb.

Hurricane Olivia weakened slowly on Saturday, but it still had a well organized circulation.  There was a circular eye at the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Olivia.  The rainbands in the eastern half of the circulation were stronger than the bands in the western half of the circulation.  Storms near the core of Olivia were generating upper level divergence.

Hurricane Olivia will move through an environment that could allow it to remain a hurricane for several more days.  Olivia is currently over water where the Sea Surface Temperature is near 25°C, but it will move over slightly warmer water during the next several days.  An upper level trough north of Hawaii will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear and they could cause Hurricane Olivia to weaken to a tropical storm early next week.

Hurricane Olivia will move south of a subtropical high over the Eastern North Pacific Ocean.  The high will steer Olivia toward the west during the next day or two.  The ridge is forecast to strengthen early next week and it will steer Olivia more toward the west-southwest.  On its anticipated track Hurricane Olivia could approach Hawaii on Tuesday night.

Elsewhere, Tropical Storm Norman moved north of Hawaii and weakened, while Tropical Depression Eighteen-E developed southwest of Baja California.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Norman was located at latitude 26.0°N and longitude 154.4°W which put it about 395 miles (630 km) northeast of Honolulu, Hawaii. Norman was moving toward the northwest at 9 m.p.h. (15 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 998 mb.

At 11:00 a.m. EDT on Saturday the center of Tropical Depression Eighteen-E was located at latitude 16.1°N and longitude 115.9°W which put it about 610 miles (980 km) southwest of the southern tip of Baja California.  It was moving toward the west-northwest at 12 m.p.h. (19 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.