Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
089 FXHW60 PHFO 141953 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 953 AM HST Fri Jun 14 2024 .SYNOPSIS... High pressure will linger northeast of the Hawaiian Islands into next week, producing moderate to breezy trade winds. Weak upper level troughing will keep brief showers in the forecast, favoring windward and mountain areas. Drier conditions are expected for leeward locations. Additionally, clouds and showers will develop along the Kona slopes of the Big Island each afternoon and evening. && .DISCUSSION... Latest satellite and radar imagery this morning shows that low clouds and a few showers are favoring typical windward and mountain areas, especially across Maui and the Big Island. Meanwhile, an upper jet stream over the region is spreading thin, high level cirrus clouds over the state from the northwest. High pressure is centered far northeast of the islands, producing moderate to breezy easterly trade winds across the state. The surface high far northeast of the islands will linger through this weekend and into next week. This feature will maintain a fairly typical moderate to breezy trade wind weather pattern into the foreseeable future with little day-to-day variation. Weak upper level troughing will keep inversion heights between 5,000 to 7,000 feet for much of the forecast period. Expect brief showers at times, mainly over windward and mountain areas. It is possible that a weak low-level easterly wave on Saturday night could produce a slight boost to shower activity through Sunday morning. Otherwise, showers will be fairly brief and light, and coverage will be greatest during the overnight to early morning hours each day. Drier conditions are forecast over leeward locations, with the exception of the Kona slopes of the Big Island, where daytime surface convergence will increase clouds and introduce isolated showers each afternoon. Not much day-to-day change in the forecast is expected over the next seven days. Increasing trends in the easterly trade wind speeds may develop next week from Wednesday onward. && .AVIATION... Moderate to breezy trade winds should continue over the next few days. Low cigs and SHRA will favor windward and mauka areas, with brief periods of MVFR conds possible. A few SHRA may make it over to leeward areas at times, but otherwise VFR conds should prevail. AIRMET Sierra is in effect for mtn obsc for windward Big Island. && .MARINE... Easterly trades will remain locally breezy through the weekend and much of next week as a surface ridge persists north of the area. A Small Craft Advisory (SCA) remains in effect for the windier channels and waters around Maui County and the Big Island through Saturday and will likely be extended later today through the weekend. The ridge may weaken slightly early next week, causing winds to decrease a bit. However, the SCA for the windier waters may continue through the forecast period. A High Surf Advisory remains posted for all south facing shores as a long period south swell continues to gradually build today. This swell could approach warning-levels late tonight and Saturday as the swell peaks. A gradual downward trend is expected Sunday into early next week. After this swell moves out, very little swell is expected next week after Tuesday. North-facing shore surf will become flat for the next few days. Small medium period northwest pulses may provide a tiny bump Sunday night into middle of next week. Surf along east-facing shores will remain small and choppy each day due to a limited trade wind fetch upstream of the islands. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST Saturday for south facing shores. Small Craft Advisory until 6 PM HST Saturday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Vaughan AVIATION...Walsh MARINE...Powell