Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
676 FXHW60 PHFO 081321 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 321 AM HST Sat Jun 8 2024 .SYNOPSIS... Light to gentle easterly trade winds are expected today, with a ridge north of the state. As the ridge lifts north tonight and Sunday, moderate to locally breezy easterly trade wind will build in. Very stable conditions will greatly limit shower activity through the weekend, with a slight increase in windward showers expected Monday and Tuesday. A more typical trade wind pattern should return by the middle of next week. && .DISCUSSION... As anticipated, no significant updates to the forecast this morning. A ridge remains just north of Kauai, bringing a hybrid sea breeze and gentle easterly trade wind flow across the state. Land breezes overnight have cleared the skies in most areas. Anticipate some clouds to develop later this morning and during the afternoon with some sea breezes setting up. Very little in the way of rainfall is expected. The ridge will begin to lift northward and shift eastward this afternoon and evening, which will shift the winds to the northeast for a brief time. Expect moderate to locally breezy easterly trades to build back in Sunday, and then persist into the middle of the week as the ridge continues to shift northeast of the state. Clouds and showers will return to the more typical windward and mauka areas with the returning trades, however shower activity will remain limited due to very stable conditions from low inversion heights, and a dry airmass. The trade wind inversion will begin to lift early next week, which should bring a slight increase in trade wind showers Monday and Tuesday, but will still remain drier than normal for this time of year. A more typical trade wind pattern should return during the middle to latter half of the week with rising inversion heights. && .AVIATION... Light trade winds will strengthen slightly to become locally breezy by this afternoon and continue to gradually strengthen into Sunday. While land breezes have helped to clear out cloud cover overnight, sea breezes may have a harder time developing this afternoon with the uptick in trade winds...but expect some cloud build up over sheltered leeward areas. Shower activity will continue to remain limited. With the strong inversion in place, ceilings will be quite low with any clouds...which will allow for periods of MVFR conditions. Otherwise, VFR conditions will prevail. No AIRMETs are currently in effect. However, AIRMET Sierra for tempo mountain obscuration may be needed at times as low clouds periodically impact mainly windward slopes with the exception of the leeward slopes and coast of the Big Island. && .MARINE... A weak elongated ridge in the northern offshore waters will move northward as high pressure redevelops north of the state this weekend. Winds are expected to gradually restrengthen tonight allowing moderate to locally strong trade winds to build back across the waters. A Small Craft Advisory (SCA) is likely for the typical windier waters around Maui County and the Big Island starting tonight through at least the first part of next week. Moderate to locally strong trade winds look to dominate the forecast over the next week. The current High Surf Advisory (HSA) for south facing shores has been extended through Monday afternoon. Although the current south- southwest swell has declined slightly from its peak and surf may come down just below HSA levels today, a bigger moderate long period south- southwest swell is expected to slowly fill in this afternoon as long period forerunners arrive, then peak Sunday night into Monday. In the long range, another moderate long period south swell may generate solid HSA level surf, but below High Surf Warning level criteria late next week. A tiny pulse from the northwest will give a slight bump for north facing shores. Wind waves for east facing shores have diminished significantly and will remain small today before ramping back up as wind wave chop increases due to the trade winds. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST Monday for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai West- Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast. && $$ DISCUSSION...M Ballard AVIATION...Farris MARINE...Shigesato