Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
766 FXHW60 PHFO 091353 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 353 AM HST Sun Jun 9 2024 .SYNOPSIS... Moderate to breezy trade winds will continue to strengthen through the middle of next week as high pressure slowly rebounds to our north. Scant trade showers will favor windward shores and slopes. && .DISCUSSION... Moderate trade winds continued overnight, with locally breezy conditions noted in the eastern channels, in spite of a weakened ridge to our north. Latest soundings showed a dry and stable airmass, thanks to strong ridging aloft, with less than an inch of PW and positive lifted index values. Steep inversions near 4000 feet worked to limit cloud development and rainfall, especially away from windward areas. Radar shows almost no shower activity within range. Models show the ridge to our north will rebound through the forecast period as a hampering mid-latitude trough farther to the north lifts out. Trades will continue to strengthen across local waters as upper ridging shifts north and east of the islands through early next week. Expect a trade wind weather pattern through the forecast period, with clouds and showers favoring windward areas. Total rainfall will be light. && .AVIATION... Breezy trades will continue to gradually increase through the rest of today. With high pressure and dry air in place over the region, SHRA activity will be limited. A strong inversion will keep low cigs allowing for periods of MVFR conds. Otherwise, VFR conds should prevail. No AIRMETs currently in effect. && .MARINE... Moderate to locally strong easterly trades will increase into the fresh to strong range today and continue through much of the week as the surface ridge strengthens to the north. This may lead to the Small Craft Advisory expanding to the Kaiwi Channel and Maui County Windward waters by Monday. 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 remain up through the week due to an active pattern within our swell window near New Zealand. Overlapping, long-period, south to south-southwest swells are expected, with the next one beginning to fill in early this morning (peak energy centered within the 18-22 second bands at the buoys). Guidance shows this swell peaking late tonight through Monday. A downward trend is anticipated Tuesday 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. Surf along north-facing shores will remain up slightly through the first half of the week as small north to north-northwest pulses move through. The next north pulse should fill in late Monday, with a small north-northwest swell arriving Tuesday into midweek. A return to summertime/flat conditions is likely later this week through next weekend. Surf along east-facing shores should trend up later this week as the trades become established locally and upstream across the eastern Pacific. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST Monday for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai West- 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 AM HST Tuesday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Powell AVIATION...Walsh MARINE...Gibbs