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.