Tag Archives: Niihau

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 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.