Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
644 FXHW60 PHFO 231314 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 314 AM HST Thu May 23 2024 .SYNOPSIS... Moderate to breezy easterly trade winds will linger over the islands through the upcoming weekend. Clouds and showers will favor typical windward and mauka areas. && .DISCUSSION... Aside from some scattered showers over the Oahu and Kauai leeward waters; satellite and radar imagery continues to show low clouds and showers over mainly windward and mauka areas with patchy high clouds across the region early this morning. As expected, winds across the state have turned easterly overnight as the trough west of Kauai moves further away and the 1036 mb high currently 1300 miles north-northeast of Honolulu slowly drifts west. Not much has changed with the forecast through the upcoming weekend. Moderate to breezy easterly trades will continue into the weekend as a series of reinforcing highs build to our north. Guidance continues to show drier air filtering into the region over the next couple of days resulting in a stable trade wind pattern. Expect mainly windward and mauka showers, with showers increasing in intensity and coverage during the overnight and early morning hours. A few of these showers may briefly spill over into leeward areas. The biggest change to the forecast revolves around the evolution of the trough to the west of Kauai over the weekend. Guidance now shows the trough somewhat lingering in the region through early next week. This may cause the winds over the western end of the state to weaken slightly and become more southeasterly by early next week resulting in localized land/sea breezes across sheltered leeward areas of Oahu and Kauai. Otherwise, expect windward and mauka showers to continue through next week under moderate to locally breeze east to southeast winds. && .AVIATION... Moderate to breezy easterly trade winds will blow across the Hawaiian Islands today. Isolated to scattered showers today will favor the windward slopes. Brief MVFR conditions are possible in moderate showers. AIRMET Sierra for mountain obscuration remains in effect for windward areas of Kauai, Oahu, Maui and the Big Island. Low cloud ceilings should decrease in coverage later this morning leading to cancelling this AIRMET for most of the affected areas. && .MARINE... High pressure will gradually build westward well to the north of the state through Friday, strengthening the trade winds across the island chain. Fresh to strong trade winds over the eastern end of the state will expand westward over the Oahu and Kauai waters today and hold at those levels through Friday. A Small Craft Advisory is now in effect for most waters around Maui and the Big Island through 6 AM Friday, and for the windier areas through 6 PM Saturday. A trough of low pressure will amplify to the west of the islands this weekend and linger into early next week. This may ease the trades and shift them around to a more east-southeasterly direction over the western end of the state, while moderate to strong easterly trades prevail over the eastern waters. South shore surf will remain small and below the summertime average through the middle of next week, with only small inconsistent pulses of southwest swell expected. The next significant south-southwest swell appears to move in late next week. East shore surf will remain near the seasonal average through Friday. A slight decrease is expected this weekend through the middle of next week as the trades ease over and upstream of the islands. Surf along north shores will remain very small with a slight bump possible late Sunday through Monday. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Friday for Maui County Windward Waters-Big Island Windward Waters. Small Craft Advisory until 6 PM HST Saturday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Ahue AVIATION...Bohlin MARINE...Jelsema