Last Updated on Wednesday, 16 April 2014 07:47
Winds Statewide in a glance ...just go HERE(this link is also the 4th drop down under weather)
Apr 16, 2014 4:00 AM HST
Moderate trade winds will continue through the weekend and into next week, possibly peaking in strength around Sunday night. Active showers moving in on the trades will diminish today, and then increase from Thursday into Friday, but then eventually become limited mainly to windward slopes.
Surface observations around the main Hawaiian islands still reported moderate to locally strong trade winds blowing. Precipitable water in the air mass was near typical values around the state, and slightly higher upwind, though drier air prevailed in most other directions.
Through most of the night, a weakening mid-level trough to the northeast through east provided uplift, raising the inversion height and encouraging showers passing under it to develop more than usual. These showers then trained over the islands from the east. However, as the trough weakened gradually, this stream of showers diminished with time. Rain rates approached moderate strength in some areas, but accumulation overall remained on the light side.
Guidance generally agreed that through the short run, moderate to strong, if flat, ridging aloft extending over the islands from the northwest will expand further toward the east, while the trough will continue to recede toward the northeast. The resulting deep ridging then will persist through the rest of the forecast period, displacing the storm track too far north to have much influence on the state.
Under these conditions, the subtropical ridge at the surface will receive enough support from aloft to keep trade winds blowing through the weekend and into next week. Solutions did differ somewhat with respect to wind speeds over time, but the consensus kept speeds near moderate levels throughout, with a possible peak near Sunday night.
Deep ridging also will tend to lower the inversion height over time, and guidance predicted the air mass to dry a bit, so shower activity will diminish. However, solutions supported a plume of more humid air to train over Maui and Hawaii counties from Thursday through Friday. Thus, pops and related fields have been increased slightly through this time. Also, orographic forcing will continue to squeeze out some moisture along windward slopes, so the greatest drying will occur mainly leeward.
The small craft advisory /sca/ was extended through this afternoon for the channels and waters around Kauai and Oahu, and continued through Friday for typically windier areas around Maui and the Big Island. Trade winds will diminish somewhat today, but then remain moderate to fresh through Friday. Wind waves produced by the persistent trade winds also will continue to require a high surf advisory for east-facing shores through this afternoon.
A small swell from the west northwest will arrive late today, and then peak Thursday below the advisory levels. No other significant swells are expected.
High surf advisory until 6 pm HST this evening for Kauai windward, Oahu Koolau, olomana, Molokai windward, Maui windward west, windward Haleakala, south Big Island, Big Island north and east.
Small craft advisory until 6 pm HST Friday for Maalaea Bay, Pailolo channel, Alenuihaha channel, Big Island leeward waters, Big Island southeast waters.
Small craft advisory until 6 pm HST this evening for Kauai northwest waters, Kauai windward waters, Kauai channel, Oahu windward waters, Kaiwi Channel, Maui county windward waters, Big Island windward waters.