Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
886 FXHW60 PHFO 160628 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 828 PM HST Sat Jun 15 2024 .SYNOPSIS... Breezy trade wind conditions will persist through the upcoming 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 late Monday through midweek due to an upper 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 8,000 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 low 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 areas 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 trades will continue at least through midweek. Low cigs and SHRA will favor windward and mauka zones. Brief periods of MVFR conds are possible. A few SHRA may make it to lee sides heading into Monday. As SHRA and clouds increase AIRMET Sierra may be needed for mtn obsc for windward locations. AIRMET TANGO is in effect for low level turb lee of terrain due to gusty trade winds. && .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. Surf along south facing shores will remain at High Surf Advisory thresholds through tonight. Surf heights will continue to decrease as the swell fades during the next few days. Only background small, medium to long period, south to southeast swell energy will move into the region for the rest of next week. North shore surf will see only small medium period northwest pulses providing a tiny bump 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 Advisory until 6 AM HST Sunday 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 Monday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Gibbs AVIATION...Walsh MARINE...Bohlin