Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
529 FXHW60 PHFO 080631 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 831 PM HST Fri Jun 7 2024 .SYNOPSIS... Light to gentle easterly trade winds will persist into Saturday as a ridge of high pressure meanders north of the state. Trade winds will briefly shift out of the northeast as a ridge of high pressure moves from west to east, north of the state then gradually strengthen. Moderate to locally breezy easterly trade wind conditions are expected by Sunday, and persist into the middle of the new week. 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... No updates to the forecast this evening, and only anticipate minor tweaks with the morning package. A ridge remains just north of Kauai, bringing a hybrid sea breeze and gentle easterly trade wind flow across the state. This afternoon we saw low level clouds confined along windward slopes and select leeward slopes where sea breezes had become well established, with rainfall totals remaining light. Land breeze are expected tonight that will help clear some clouds, especially for leeward areas through the overnight hours. This dry hybrid trade wind and land/sea breeze pattern is expected to persist into Saturday. The ridge will begin to lift northward and shift eastward Saturday afternoon and evening, and that will shift the winds to the northeast for a brief time. Expect moderate to locally breezy easterly trades to build back in on 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... A ridge of high pressure just north of the state will maintain light trade winds across the region tonight into Saturday. Land breezes will help to clear some cloud cover across sheltered leeward areas later tonight, but with the trades expected to strengthen to become locally breezy by tomorrow afternoon, sea breezes may have a harder time developing. Shower activity will continue to remain limited due to a strong ridge of high pressure aloft. With the strong inversion, ceilings will be quite low with any clouds, which will allow for periods of MVFR conditions. AIRMET Sierra is in effect for tempo mountain obscuration for parts of the Big Island. Satellite imagery shows some low clouds moving in across most of the island chain early this evening, which may temporarily bring MVFR conditions to these areas. Land breezes should eventually help clear the clouds over for leeward areas, but it may take most of the night to fully clear out. && .MARINE... A weak elongated ridge in the northern offshore waters will hold in place over the region. Expect wind speeds to remain below Small Craft Advisory (SCA) threshold through the day Saturday. High pressure will redevelop north of the state over the weekend, allowing moderate to locally strong trade winds to build back. Models show the potential for SCA conditions across typical windier waters around Maui County and the Big Island as early as Saturday afternoon through early next week. The current south-southwest swell has peaked and will hold through tonight before steadily declining Saturday. A High Surf Advisory (HSA) for all south facing shores is in effect through tonight. A bigger moderate long period south- southwest swell will build through Saturday, then peak Sunday night into Monday. The HSA will likely be dropped Saturday morning than reissued coinciding with the next swell as it is likely it will generate HSA criteria surf at its peak. Yet another long period south swell may generate HSA threshold surf late next week. The current small northwest swell continues to decline. However, a reinforcing pulse from the northwest will continue tonight and give north facing shores a small bump. Wind waves for east facing shores have diminished significantly and will remain small into the weekend. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 AM HST Saturday 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