Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
148 FXHW60 PHFO 020157 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 357 PM HST Wed May 1 2024 .SYNOPSIS... Trade winds will strengthen on Thursday and become breezy Friday through the weekend. Rainfall will favor typical windward slopes, with an increase in showers expected this weekend through the first half of next week as a disturbance aloft passes overhead && .DISCUSSION... High pressure centered far northeast of the state and a trough just northwest of Kauai will maintain light to moderate east to east-southeast winds over the western half and moderate easterly trades over the eastern half of the state through tonight. For tonight, we should see fairly dry conditions with a few scattered over windward areas and isolated showers possible over leeward areas. As the trough weakens and shifts westward on Thursday, high pressure will build over the region and trade winds will strengthen. By Friday, breezy trades are expected across the state with locally strong trades over windier areas of Maui County and the Big Island. As the trades strengthen, showers will also increase primarily over windward and mauka areas. An upper level low approaching the state from the west this weekend, should help enhance the showers and will allow for brief downpours this weekend into early next week. Although details are still uncertain, windward and mauka areas could be come quite showery through early next week, especially the western end of the state where the best instability exists. && .AVIATION... Moderate E to ESE winds will gradually strengthen through Thursday, with random clusters of showery low clouds delivering brief periods of isolated MVFR VIS/CIG in SHRA, mainly windward. VFR conditions will prevail leeward, except for isolated areas of MVFR VIS/CIG over leeward Big Island in the afternoon and evening. No AIRMETs are posted, but increased low-level turbulence to the lee of the terrain is expected by Thursday, likely prompting the issuance of AIRMET Tango. && .MARINE... High pressure far northeast of the state will shift south and dissipate even as a second high builds to the north. Moderate to locally strong trade winds will strengthen to fresh to locally strong on Friday and persist into Monday. A Small Craft Advisory (SCA) remains in effect for typical windy waters around the Big Island and Maui through tomorrow night. This advisory will likely be expanded to include additional waters as winds increase. Along north and west facing shores, tiny surf will persist through Friday. On Friday night, a small long-period swell will fill in, triggering a small bump in the surf on Saturday. Lastly, a storm low currently near the Kuril Islands will send another small, long period northwest swell late Sunday that will maintain small surf along north and west facing shores into early next week. For south facing shores, small background south swells will continue through Friday. A new small, long period swell should fill in over the weekend providing a boost in surf along south facing shores through early next week. Along east facing shores, small, choppy surf will become rough and choppy on Thursday in response to the strengthening trade winds. Conditions are expected to persist through the weekend and into early next week. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Thursday for Pailolo Channel- Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Kino AVIATION...Birchard MARINE...Bedal/Vaughan