Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
207 FXHW60 PHFO 071944 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 944 AM HST Sun Jul 7 2024 .SYNOPSIS... A stable, moderate trade wind pattern will prevail through Monday with mainly light showers focused over the windward and mountain areas. Increasing trade winds and slightly wetter conditions are expected during the middle of the week, with breezy trades continuing into next weekend. && .DISCUSSION... A stable, moderate trade wind flow will continue to focus limited rainfall over windward slopes into tomorrow. Broad surface high pressure driving the trades is bisected in the far northern Pacific by a large, but somewhat weak, area of low pressure. As this low lifts northward on Monday, trades may increase only slightly. Meanwhile, a strong mid- to upper-level ridge parked over the islands will maintain very stable conditions with an inversion based around 5000 to 7000 ft. Aside from a small batch of moisture moving across Oahu this morning, expect limited windward rainfall through Monday. The Kona slopes of the Big Island will experience spotty afternoon and evening showers, while remaining leeward areas will be rather dry. Trade winds will strengthen as showers pick up Monday night and Tuesday. Trades winds increase to locally breezy levels as the broad ridge to the north builds and the surface low lifts northward. A batch of shallow moisture, currently located about 300 miles east of Hilo, will bring increased showers Monday night, followed by another area on Tuesday night. The mid-level ridge will initially hold, limiting shower intensity. However, a mid-level trough approaching from the southeast will lead to borderline Wind Advisory conditions on the high summits of the Big Island. The mid-level trough will weaken as it passes over the islands on Thursday, causing winds on the summits to decline and likely having little influence on rainfall. Breezy trade winds and a typical pattern of mainly windward showers will prevail Friday into next weekend. && .AVIATION... Moderate to locally breezy trade winds are expected to continue through Monday. Periods of clouds showers will be possible, mostly over windward and mauka areas, bringing occasional MVFR ceilings and visibilities today. AIRMET Sierra is posted for mountain obscurations above 2500 feet for the island of Oahu. Other windward slopes could have AIRMET Sierra later today as stable low clouds move in from the east. VFR will prevail over most leeward areas today. && .MARINE... High pressure far northeast of the state will keep moderate to locally fresh trade winds into Monday. The ridge to the north looks to strengthen over the next few days and will bring back moderate to locally strong trade winds Tuesday. A Small Craft Advisory will likely go back up for the typical windy waters around Maui County and the Big Island. Small surf will hold along south facing shores over the next few days as the current small south-southeast swell slowly declines. A small south-southwest swell could begin to fill in late Monday, which should maintain small surf along south facing shores through Wednesday. Into the long range, a low pressure system currently deepening southeast of New Zealand will send a series of south swells next weekend into the first half of the following week. Surf along north facing shores will remain tiny with a small northeast swell wrapping into select north facing shores today. This northeast swell should decline on Monday. Surf along east facing shores will trend up Tuesday as trade winds strengthen across the region. The combination of higher than normal water levels and afternoon spring tides are resulting in water levels running over half a foot above guidance around the Big Island and Maui. This will cause minor coastal flooding issues for both Big Island and Maui this afternoon during peak high tide. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Wroe AVIATION...Foster MARINE...Kino