Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
003 FXHW60 PHFO 150632 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 832 PM HST Fri Jun 14 2024 .SYNOPSIS... Breezy trade wind conditions will persist through next week. Clouds and showers will predominantly favor windward and mauka areas overnight into the morning as areas of moisture move through. An increase in windward shower coverage is possible from Monday night through midweek due to a mid- to upper-level disturbance drifting westward across the state. Some of these showers may briefly extend to the dry leeward areas of the smaller islands. && .DISCUSSION... Guidance remains consistent, showing a strong surface ridge north of the state throughout the upcoming week, possibly strengthening later on. This will sustain breezy easterly trade winds with clouds and mostly brief showers favoring windward and mauka locations. The trade wind inversion will be situated between 6,000 and 7,500 feet, and precipitable water (PW) levels will generally range from 1.0 to 1.25 inches. Rainfall amounts will likely be limited, even in windward areas, except possibly during the first half of the week when an upper-level trough moves westward across the state, drawing up more moisture. Guidance indicates PW values increasing above average starting Monday night through Tuesday in the eastern part of the state, and later spreading to the western areas by Tuesday night into midweek. While most showers during this period will favor windward and mauka areas, some could reach leeward areas, especially Tuesday night into Wednesday. This pattern of occasional light showers in our typically dry leeward regions may persist into the latter part of next week as the pressure gradient tightens, resulting in brisk easterly trades across the islands. && .AVIATION... Moderate to locally breezy trade winds will continue. Clouds and light showers will favor east and northeast facing slopes and coasts. Isolated spillover showers are expected along leeward slopes of the smaller islands, especially in the late night and morning hours. Brief MVFR CIG/VIS are possible in passing showers, otherwise VFR conditions will prevail all areas. A weak eddy just west of the Big Island will keep the leeward coast and adjacent waters of the Big Island south of Hilo shrouded in VFR cloudiness overnight. Clouds should lift and dissipate after sunrise tomorrow morning. AIRMET Sierra remains in effect for mountain obscuration along windward slopes of the Big Island. Elsewhere, Brief MVFR CIG or VIS are possible in passing showers, otherwise VFR conditions will prevail all areas. && .MARINE... A high pressure ridge north of the islands will keep moderate to strong trade winds blowing across the Hawaii region. A Small Craft Advisory (SCA) remains in effect for the windier channels and waters around Maui County and the Big Island through the weekend. This SCA for the windier waters may continue into much of next week. The High Surf Warning (HSW) continues through noon Saturday as a long period south swell continues to roll through the islands. Surf observations show surf heights remaining at low end warning thresholds this evening. A gradual downward trend is expected from Saturday night into early next week. After this south swell moves out, only background small medium to long period south to southeast swell energy will move into the region through the rest of next week. North shore surf will remain small for the next few days. Small medium period northwest pulses may provide a tiny bump Sunday night into middle of next week. Surf along east shores will remain small and choppy each day due to continued trade winds. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Warning until noon HST Saturday for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast. Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Gibbs AVIATION...Bedal MARINE...Bohlin