Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
509 FXHW60 PHFO 111349 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 349 AM HST Tue Jun 11 2024 .SYNOPSIS... Moderate to breezy trade winds will persist through rest of the week as broad high pressure remains north of the state. Stable conditions will focus limited showers over windward areas, and leeward areas will be rather dry, though leeward Big Island will experience clouds and showers each afternoon and evening. && .DISCUSSION... A breezy and stable trade wind flow is producing a somewhat dry June weather pattern. A 1030 mb surface high centered about 1000 miles north of Kauai is driving the trades, and a mid-level ridge is maintaining an inversion near 6000 feet has been measured. Little change is expected through the week. The surface high will move eastward during the next several days and settle far northeast of the state by Saturday. A surface ridge trailing the high will remain north of the islands, but it may be weakened enough for us to experience a subtle decrease in trade winds for Friday into the weekend. Persistent mid-level ridging over the state will maintain a stable pattern of mainly windward rainfall through at least Friday. Aside from afternoon showers on the Kona slopes of the Big Island, somewhat dry weather will persist for leeward areas. Random pockets of shallow moisture moving along the trade wind flow will periodically boost windward rainfall, and one such area is expected tonight into Wednesday. A weak disturbance aloft could drive an increase in showers during the weekend. && .AVIATION... Breezy and mostly dry trades will hold steady. SHRA and MVFR conds should be confined to windward and mauka locations through the period. Otherwise VFR conds will prevail. No AIRMETs currently in effect. && .MARINE... Fresh to strong easterly trades will continue through much of the week, as the surface ridge remains north of the area. This supports the Small Craft Advisory continuing for the windier channels and waters around Maui County and the Big Island. Guidance suggests a potential weakness forming in the ridge northwest of the state next weekend, which could lead to moderate to fresh east-southeast trades. Surf along south facing shores will hold just under the advisory level this morning as the south-southwest swell that peaked early Monday steadily lowers. Observations at the offshore buoys reflect this lowering trend early this morning, with the peak energy shifting down into the 13 to 15 second bands. This trend will continue through midweek, with mainly a mix of the fading south- southwest swell and a small, medium-period southeast swell. A fresh, long-period south swell is expected to arrive Thursday night into Friday, then peak late Friday into Saturday. This swell will hold through early next week as it slowly fades. Surf along north-facing shores will remain up above the summertime average (flat) through a good portion of the week as small, short-period north to north-northwest swells move through. Surf along east-facing shores will remain small and choppy through the week, with a limited trade wind fetch across the eastern Pacific. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Foster AVIATION...Walsh MARINE...Gibbs