Issued: Feb 09, 2010 7:30 PM HST
Based on data through 7:00 pm Feb 09 2010 HST
A surface ridge about 150 miles north of Kauai and strong high pressure aloft are in control of weather across the main Hawaiian islands, while a front 325 miles northwest of Kauai is advancing toward the east at 30 to 40 mph.
A stable trade wind cloud distribution is noted across the state this evening. The ridge to the north is producing a weakening trade wind flow, while a high aloft centered over the islands is producing very stable conditions and is allowing only scattered to locally broken stratocumulus clouds over waters hundreds of miles around the islands. These clouds are travelling from the east around 20 mph east of the Big Island, ease to about 15 mph north of Oahu, then decrease to 10 mph and veer out of the east southeast near Kauai. These clouds are piling up on windward exposures of the islands, producing broken cloud conditions. Afternoon sea breezes have also created areas of broken low clouds over leeward terrain on the smaller islands, while all of the leeward Big Island and most of Kau are covered with broken to overcast low clouds.
An upper level trough centered north of 20°N and west of 170°W is driving a cloud front currently moving across French Frigate Shoals. The front is comprised of a 250 mile-wide band of overcast cumulus clouds from 30°N 162°W to 25°N 165°W moving to the east at 30 to 40 mph. The band slows and narrows to 100 miles wide from 25°N 165°W to 21°N 170°W to 17°N 178°W. The upper level trough is also generating an area of scattered to broken high clouds south of the front west of 165°W.
