Last Updated on Tuesday, 18 June 2013 07:28
Winds Statewide in a glance ...just go HERE(this link is also the 4th drop down under weather)
Jun 18, 2013 3:45 AM HST
Synopsis
A trade wind weather regime will continue into the upcoming weekend with showers favoring mainly the windward and mountain areas, especially during the nights and mornings.
Discussion
A broad surface high pressure system located 1100 miles northeast of the islands is forecast to remain in that vicinity into the upcoming weekend. Thus, islands will continue to benefit the cooling trades that the high produces. The strength of the trades is slated to ease off slightly by Wednesday night into the moderate range, but it will rebound into the locally strong about the Friday night time frame. This weakening of the trades comes about as the high and associated ridge are being tested by a front that will not influence the islands. The front weakens, and both ridge and high rebuild late in the week resulting in the stronger trades over the weekend, and perhaps days thereafter.
No real significant change in the next 48 hours. The depth of the marine layer is slated to top 8000 feet. The layer will be moist, and with orographic influence and breezy trades, the end result is passing showers favoring the nights and mornings. The source of this low level moisture lies just upwind of the Big Island and Maui, as part of a large cloud mass covering a swath of area between the islands and west coast. The cloud mass starts off as stable stratus off the west coast but become unstable cumulus just upwind of the islands.
Some good news insight. The GFS solution is pointing to a shallower marine layer with the inversion lowering to 5 to 7 thousand feet by Thursday night, thanks to a stronger mid level ridge. The marine layer is expected to be slightly drier, so with that said, we are looking at a drier trade wind regime the second half of the week that may last into the upcoming weekend. There will still be showers, just fewer.
High level cirrus is present over the Big Island this morning thanks to an upper low near Kauai and southerly winds to the east of it carrying moisture northward from the lower latitudes. But as this low fills later today, the cirrus should be moving out.
Marine
The small craft advisory /sca/ is in effect to until 6 am HST Wednesday for the windier places around Maui and the Big Island. The SCA will be monitored closely if it needs to be extended. But the trades are expected to ease slightly by Wednesday night allowing the SCA to be dropped. The trades are expected to firm up by the weekend, with possible SCA conditions returning to the windier coastal waters around Maui and the Big Island. Moderate surf along east shores due to the trade winds.
Watches/Warnings/Advisories
Small craft advisory until 6 am HST Wednesday for Maalaea Bay, the Pailolo and Alenuihaha channels, and waters south of the Big Island.