Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
332 FXHW60 PHFO 130250 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 450 PM HST Fri Sep 12 2025 .SYNOPSIS... High pressure centered northeast of Hawaii will drive moderate to fresh trade winds with dry and stable weather into next week. An upper trough will drift through the islands from Tuesday to Thursday possibly increasing showers. && .DISCUSSION... High pressure centered northeast of Hawaii will drive moderate to fresh trade winds with dry and stable weather into next week. Visible satellite and radar show a few clouds and showers across leeward Kauai as the last bit of moisture that moved in yesterday clears the western end of the state. Scattered cirrus clouds wrapping around an upper ridge will likely continue across the area through at least Saturday. The overall pattern will change little through Monday, with the best chance for rainfall and cloud cover over the windward slopes, but accumulations will be light. A tropical wave will pass south of the state Tuesday through Thursday. Upper level troughing will set up over the state around the same time may act to enhance showers moving in on both the trade wind flow and the far northern periphery of the wave. Clouds and showers will likely increase during this time frame focusing over windward and mauka areas. && .AVIATION... Moderate to locally breezy trade winds will hold for the next few days as high pressure to the northeast remains in place. Showers will favor windward and mountain areas as well as the night time and early morning hours. MVFR conditions can be expected in any showers but overall VFR conditions are expected. No AIRMETs are in effect. AIRMET Sierra for mountain obscuration over select windward areas is possible tonight. && .MARINE... High pressure will remain in place far northeast of state through the weekend, allowing moderate to locally strong trade winds to prevail across the coastal waters. A Small Craft Advisory remains in effect for the typically windy channels and waters of Maui County and the Big Island through early Sunday. Winds may briefly weaken slightly late Sunday into early next week, then strengthen back to Small Craft Advisory levels once again by midweek. Surf along south facing shores will remain near or slightly above the September average for the next couple of days. The current small, medium-period south swell will gradually decline through Saturday, but a smaller long-period reinforcement on Sunday will maintain small south shore surf into next week. A small north northwest swell is currently moving through the region and producing elevated surf along north facing shores. Webcams today have shown sets that appear to have slightly outperformed in some spots what one would expect based on buoy observations. As a result, surf heights for north facing shores have been adjusted slightly higher through this evening, but expect them to gradually decline through late Saturday as this swell wanes. Another short- to medium-period north northwest reinforcement could cause a slight bump in surf along north facing shores on Sunday, then decline through midweek. East facing shores will see typical trade wind generated energy throughout the forecast period. .FIRE WEATHER... Humidity levels will remain dry into next week with increasing humidity and shower trends from Tuesday into Thursday as a weak low level trough drifts from east to west across the island chain. Wind speeds will likely remain below critical fire weather thresholds for the next seven days. Temperature inversion heights near the Big Island and Maui will range from 5,500 to 6,500 feet. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Sunday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Foster AVIATION...Tsamous MARINE...Vaughan FIRE WEATHER...Foster