Tag Archives: Central Pacific

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.

Hurricanes Norma and Olivia Continue Westward

Hurricanes Norman and Olivia continued to move westward across the Pacific Ocean on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Norman was located at latitude 19.9°N and 148.4°W which put it about 435 miles (700 km) east of Hilo, Hawaii. Norman was moving toward the west at 8 m.p.h.   The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (220 km/h).  The Minimum surface pressure was 962 mb.

At 5:00 p.m. EDT on Wednesday the center of Hurricane Olivia was located at latitude 17.3°N and longitude 123.5°W which put it about 960 miles (1550 km) west-southwest of the southern tip of Baja California.  Olivia was moving toward the west-northwest at 13 m.p.h. (20 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 974 mb.

Although Hurricane Norman was in seemingly a less favorable environment, it intensified on Wednesday while Hurricane Olivia weakened.  The eye of Hurricane Norman became more distinct and it strengthened back to major hurricane status.  Hurricane Olivia weakened to Category 2 on the Saffir-Simpson Scale.  Both hurricanes were similar in size.  Winds to hurricane force extended out about 30 miles (50 km) from the center of Hurricane Norman and about 25 miles (40 km) from the center of Hurricane Olivia.  Winds to tropical storm force extended out about 115 miles (185 km) from the centers of both Hurricane Norman and Hurricane Olivia.

Both hurricanes are forecast to weaken gradually during the next several days.  Hurricane Norman will move over water cooler than 26.5°C.  An upper level trough will produce westerly winds which will blow toward the top of the circulation and cause more vertical wind shear.  The combination of cooler water and more shear will cause Hurricane Norman to weaken. Hurricane Olivia is currently over water where the Sea Surface Temperature is near 28°C, but it too will move over cooler water.  An upper level ridge north of Olivia will produce northwesterly winds which will cause more vertical wind shear.  Hurricane Olivia is also forecast to weaken during the next several days.

The upper level trough is forecast to turn Hurricane Norman toward the northwest on Thursday.  On its anticipated track Hurricane Norman will pass north of the Hawaiian Islands.  The ridge north of Hurricane Olivia is forecast to steer Olivia in a general westerly direction for another four or five days.  On its anticipated track Hurricane Olivia could be east of Hawaii by the end of the weekend.

Weakening Tropical Storm Lane Moves Away from Hawaii

A weakening Tropical Storm Lane moved away from Hawaii on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Lane was located at latitude 19.5°N and longitude 160.2°W which put it about 195 miles (310 km) southwest of Honolulu, Hawaii.  Lane was moving toward the west at 9 m.p.h. (15 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 998 mb.  All Tropical Storm Warnings and Watches for the Hawaiian Islands have been discontinued.

An upper level trough west of the Hawaiian Islands produced strong southwesterly winds which blew the upper portion of the circulation of former Hurricane Lane off the lower part of the circulation.  Tropical Storm Lane consisted primarily of a well develop low level circulation of bands of showers and lower clouds.  A few thunderstorms continued to develop in outer bands on the eastern side of the circulation.

Since Tropical Storm Lane exists primarily in the lower levels of the atmosphere, it is being steered westward by a subtropical ridge over the Central Pacific Ocean.  A general westerly motion is forecast during the next several days.  The upper level trough will continue to cause strong vertical wind shear and Tropical Storm Lane will continue to weaken.

Hurricane Lane Edges Closer to Hawaii

Hurricane Lane edged closer to Hawaii on Friday.  At 5:00 p.m. EDT on Friday the center of Hurricane Lane was located at latitude 19.1°N and longitude 157.9°W which put it about 150 miles (245 km) south of Honolulu, Hawaii.  Lane was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 966 mb.

Hurricane Warnings were in effect for Oahu and Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe.  A Tropical Storm Warning was in effect for Hawaii County.  A Tropical Storm Watch was in effect for Kauai County including Kauai and Niihau.  Flash Flood Watches were in effect for all Hawaiian Islands.

Hurricane Lane weakened gradually on Friday.  There was no longer an eye at the center of circulation.  The strongest thunderstorms were occurring in  a band northwest of the center.  The strongest winds and heaviest rain were occurring in that band of storms.  Other rainbands in the northern half of the circulation were revolving around the center of Hurricane Lane.  The bands in the southern half of the circulation were weaker and they consisted primarily of showers and lower clouds.  Winds to hurricane force extended out about 35 miles from the center of circulation, primarily on the northern side of Lane.  Winds to tropical storm force extended out about 140 miles (225 km) from the center.

Hurricane Lane will continue to weaken on Saturday.  An upper level trough west of the Hawaiian Islands is producing strong southwesterly winds which were causing significant vertical wind shear.  Those winds were tilting the circulation toward the northeast and they were inhibiting upper level divergence to the west of the hurricane.  The slow movement of Hurricane Lane is allowing the wind to mix cooler water to the surface of the ocean.  Significant vertical wind shear and cooler water will cause Lane to weaken.  If the upper level winds become strong enough, there is the chance that they could blow the upper part of the circulation away from the lower level circulation.

The upper level trough will push Hurricane Lane slowly toward the north during the next 12 to 24 hours.  On its anticipated track Hurricane Lane will get closer to Maui and Oahu.  When most of the stronger, taller thunderstorms weaken, then Lane will be steered more by the winds in the lower levels of the atmosphere.  Those winds are blowing from east to west and they are forecast to Lane toward the west just before the center reaches Oahu and Maui.  Although Hurricane Lane will cause gusty winds, locally heavy rain and flash floods are the greatest risks.  Heavy rain has already fallen on the Big Island of Hawaii and Flash Flood Watches have been issued for all of the Hawaiian Islands.

Hurricane Lane Drops Heavy Rain on Hawaii

Hurricane Lane dropped heavy rain on Hawaii on Thursday.  The airport in Hilo, Hawaii reported 14.02 inches (356 mm) of rain during the past 24 hours.  At 11:00 p.m. EDT Thursday the center of Hurricane Lane was located at latitude 17.8°N and longitude 157.9°W which put it about 240 miles (390 km) south of Honolulu, Hawaii.  Lane was moving toward the north-northwest at 6 m.p.h. (10 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.

Hurricane Warnings were in effect for Oahu and Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe.  A Hurricane Watch was in effect for Kauai County including the islands of Kauai and Niihau.  A Tropical Storm Warning was in effect for Hawaii County.

Hurricane Lane began to weaken on Thursday.  An upper level trough west of Hawaii was producing southwesterly winds which were blowing toward the top of the hurricane.  Those winds were causing moderate vertical wind shear and they were obstructing upper level divergence to the west of Hurricane Lane.  The wind shear prevented the circulation from pumping as much mass away from the hurricane and the surface pressure began to increase.

Hurricane Lane retained a strong circulation in spite of increased vertical wind shear.  Winds to hurricane force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (205 km) from the center.  The core of Hurricane Lane passed over NOAA buoy 51002.  The strongest winds occurred in the northern eyewall.  The buoy measured a sustained wind speed of 83 m.p.h. (133 km/h).  It also reported a wind gust to 105 m.p.h. (170 km/h).  The winds were significantly weaker in the southern half of the circulation.

The upper level trough gradually turned Hurricane Lane more toward the north on Thursday.  A general motion toward the north is forecast for Friday.  On its anticipated track Hurricane Lane could approach Maui and Oahu on Friday night.  Lane is forecast to weaken further during the next 24 hours.  Guidance from numerical models suggests that the weaker circulation will be steered by winds in the lower levels when it nears Maui and Oahu.  The models are forecasting a turn toward the west.  Hurricane Lane could cause gusty winds and power outages.  The greater risk will be caused by the locally heavy rain, which will create the potential for flash floods.  Flash floods may develop very quickly in areas of steep terrain.

Hurricane Lane Turns Northwest, Warning Issued for Oahu

Hurricane Lane turned toward the northwest on Wednesday night and a Hurricane Warning was issued for Oahu.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Lane was located at latitude 15.9°N and longitude 156.5°W which put it about 385 miles (620 km) south-southeast of Honolulu, Hawaii.  Lane was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 939 mb.

Hurricane Warnings were in effect for Oahu, Hawaii County and Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe.  Hurricane Watches were in effect for Kauai County including Kauai and Nihhau.

Hurricane Lane weakened slightly on Wednesday but it remained a powerful hurricane.  There was a small eye 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.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Lane.  Winds to hurricane force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 140 miles (225 km) from the center.

The environment around Hurricane Lane will gradually become less favorable for a powerful hurricane.  Lane will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough west of Hawaii will produce southwesterly winds which will cause more vertical wind shear.  Hurricane Lane will gradually weaken, but it could remain a major hurricane for another 36 hours.

The upper level trough will turn Hurricane Lane more toward the north-northwest.  On its anticipated track the center of Hurricane Lane will move closer to Hawaii.  The center of Lane will be southwest of the Big Island of Hawaii in about 24 hours.  The center of Lane could be south of Oahu on Friday.  Even if the center of Hurricane Lane does not pass over any of the islands, wind blowing up the slopes of the mountains will contribute to locally heavy rain and the potential for flash floods.

Major Hurricane Lane Churns Southeast of Hawaii

Major Hurricane Lane churned southeast of Hawaii on Monday.  At 5:00 p.m. EDT on Monday the center of Hurricane Lane was located at latitude 13.6°N and longitude 149.1°W which put it about 580 miles (930 km) southeast of Hilo, Hawaii.  Lane was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  Th minimum surface pressure was 964 mb.

There was a circular eye with a diameter of 16 miles (26 km) at the center of Hurricane Lane.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Lane.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane in all directions.

The circulation of Hurricane Lane was relatively compact.  Winds to hurricane force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (205 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Lane was 25.1.  The Hurricane Size Index (HSI) was 10.3 and the Hurricane Wind Intensity Size Index (HWISI) was 35.4.

Hurricane Lane will move through an environment during the next day or two that will allow it to maintain much of its intensity.  Lane 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 relatively weak and there will not be a lot of vertical wind shear.  Hurricane Lane could remain a major hurricane for several more days.  An upper level trough will approach the hurricane from the west in 36 to 48 hours.  Stronger southwesterly winds ahead of the trough will increase vertical wind shear and Hurricane Lane will likely weaken later this week.

Hurricane Lane will move south of a subtropical ridge during the next 24 to 36 hours.  The ridge will steer Lane in a general westerly direction.  The upper level trough approaching from the west will turn Hurricane Lane more toward the northwest.  The timing and sharpness of the turn toward the northwest is still uncertain, but Hurricane Lane could move closer to the Hawaiian Islands during the middle of the week.

Hurricane Hector Passes South of Hawaii

Powerful Hurricane Hector passed south of Hawaii on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Hector was located at latitude 16.7°N and longitude 156.8°W which put it about 325 miles (525 km) south-southeast of Honolulu, Hawaii.  Hector was moving toward the west at 16 m.p.h. (26 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. (220 km/h).  The minimum surface pressure was 959 mb.

The circulation of Hurricane Hector remained circular and symmetrical.  Information from radar and satellites indicated that Hurricane Hector had a double eyewall structure.  There was a small inner eye surrounded by an inner eyewall.  The inner eyewall was thin and it appeared to be weakening.  A clear area, sometimes called a moat, surrounded the inner eyewall.  A second thicker eyewall surrounded the moat.  Several shorter bands of of showers and thunderstorms were revolving around the core of Hector.  The circulation of Hurricane Hector was relatively small.  Winds to hurricane force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force only extended out about 95 miles (155 km) from the center.

Hurricane Hector exhibited a structure that is sometimes called an annular hurricane.  Annular hurricanes often achieve an equilibrium with their environment which can persist for days if there is not much wind shear.  Hector will move over water where the Sea Surface Temperature is between 27°C and 28°C.  It will move through a region where there is little vertical wind shear.  Hurricane Hector will remain a strong hurricane and it could strengthen during the next 24 to 48 hours, if the inner eyewall dissipates completely.

Hurricane Hector will move south of the subtropical high pressure system over the Central Pacific.  The high will steer Hector toward the west for several more days.  On its anticipated track Hurricane Hector will remain south of Hawaii.

Elsewhere over the Eastern North Pacific Ocean, Hurricane John weakened west of Baja California and Tropical Storm Kristy exhibited little change on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Hurricane John was located at latitude 23.1°N and longitude 114.4°W which put it about 285 miles (460 km) west of the southern tip of Baja California.  John was moving toward the northwest at 16 m.p.h. (26 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. (155 km/h).  The minimum surface pressure was 983 mb.

At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Kristy was located at latitude 15.3°N and longitude 130.0°W which put it about 1410 miles (2220 km) west-southwest of the southern tip of Baja California.  Kristy was moving toward the northwest at 7 m.p.h. (11 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 1002 mb.