Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
778 FXHW60 PHFO 130638 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 838 PM HST Wed Jun 12 2024 .SYNOPSIS... A high pressure ridge will linger north of the Hawaiian Islands through the week producing moderate to breezy trade winds. Weak upper level troughing will keep brief periods of windward showers in the forecast favoring windward and mountain areas with drier conditions over leeward locations. Clouds and showers will develop along the Kona slopes of the Big Island each afternoon and evening. && .DISCUSSION... A fairly typical moderate to breezy trade wind weather pattern will continue as a high pressure ridge remains locked in place north of the Hawaiian Islands into next week. Weak upper level troughing will keep the trade wind temperature inversion heights between 5,000 to 7,000 feet for much of the forecast period. Trade wind inversion heights at this level will keep brief periods of shower activity in the forecast, mainly over windward and mountain areas as the trade winds lift the moisture over the windward mountain peaks. Shower activity in these windward mountain areas will trend higher in the overnight to early morning hours. Drier conditions are forecast over leeward locations. High level cirrus clouds will move over the state into the weekend, enhancing sunrise and sunset colors. Not much day to day changes in the weather forecast over the next seven days. A slight increasing trend in the easterly trade wind speeds may develop around the middle of next week. && .AVIATION... Moderate to breezy trade winds will persist over the next couple of days. SHRA and low cigs will favor windward and mauka areas bringing brief periods of MVFR conds. Otherwise, VFR conds should prevail. AIRMET Sierra for mtn obsc is in effect for windward portions of the smaller islands. This AIRMET may be needed for windward areas along portions of the island chain overnight into tomorrow morning. && .MARINE... Fresh to strong easterly trades will continue through the weekend, as the surface ridge remains north of the area. This supports the Small Craft Advisory (SCA) continuing for the windier channels and waters around Maui County and the Big Island each day. A slight uptick is expected Thursday into Friday, which could expand the SCA to other zones. Surf along south facing shores will slowly ease through Thursday as the current south-southwest swell fades. Expect a mix of this fading south-southwest swell and a small, medium-period southeast swell through Thursday. A fresh, long-period south swell is expected to arrive Thursday night into Friday, then peak late Friday into Saturday. This swell should produce advisory level surf Friday into Saturday then gradually decline Sunday into early next week. Surf along north-facing shores will remain up above the summertime average (flat) through a good portion of the week and into next week as small, short-period north to north-northwest swells move through. Surf along east-facing shores will remain small and choppy over the next several days due to limited trade wind fetch upstream of the islands. A slight increase is possible on Friday as the winds upstream of the state strengthens. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Saturday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Bohlin AVIATION...SMW MARINE...Gibbs