Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
840 FXHW60 PHFO 110151 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 351 PM HST Wed Sep 10 2025 .SYNOPSIS... Locally breezy trades deliver clouds and showers windward and mauka into next week. && .DISCUSSION... Diurnally-driven interior showers over Kauai and Oahu will dissipate with the loss of heating this evening. Strong 597dm ridging anchored just west of the International Dateline builds east through the latter half of the week allowing the trade wind belt to rebound northward and strengthen slightly as typical mid- level stability returns. This in turn favors a return to locally breezy trades which will deliver periodic batches of clouds and showers windward and mauka through the forecast period. Prospects for meaningful rainfall remain limited during this time largely owing to a lack of upstream moisture. && .AVIATION... An area of enhanced moisture over the western half of the state has resulted in lower clouds, showers, and periods of MVFR over mainly Kauai and windward Oahu this afternoon. This prompted the expansion of AIRMET Sierra for mountian obscuration to these areas, with conditions continuing into this evening. Otherwise, expect mainly VFR conditions across the rest of the state tonight and Thursday with moderate to breezy trades keeping clouds and showers over mainly windward and mauka areas. && .MARINE... The remnants of Post-Tropical Cyclone Kiko continue to track northwest this afternoon as it weakens just north of the coastal waters. As this occurs, moderate to locally fresh east to southeast trade winds have begun filling in from east to west across the island chain today. By Thursday, high pressure will build north of the coastal waters, marking a return of moderate to locally fresh trade winds. By Friday, a Small Craft Advisory may be needed once again for the typically windy waters and channels around Maui County and the Big Island as locally breezy trades return. Any lingering easterly swell generated from Kiko will fade tonight, with surf along east-facing shores returning to the more typical trade wind-generated energy on Thursday as moderate to fresh trades fill back into the region. Surf along south facing shores will remain near or just below the September average for the next few days. A reinforcing south- southwest swell peaked today and will slowly decline through Thursday. Another small bump from the south is possible on Friday. Additionally, multiple small pules of northwest to north- northwest swell energy will generate small surf along north facing beaches throughout the rest of this week and into the weekend. && .FIRE WEATHER... The return of locally breezy trades will lower humidity to typical values during the remainder of the forecast period. Showers remain rather limited and focused windward and mauka. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...JVC AVIATION...Ahue MARINE...Vaughan FIRE WEATHER...JVC