Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
415 FXHW60 PHFO 190600 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 800 PM HST Tue Aug 18 2026 .SYNOPSIS... A more seasonal trade wind pattern has returned to the state with the exit of Hurricane Lala. Expect typical trade wind showers focused along windward and mauka areas through tonight. Trade winds weaken Wednesday into the latter half of the week as a trough passes northeast of the islands. The trough also brings an increase in moisture that will produce an uptick in shower activity through Friday. This weekend, trade winds restrengthen. && .SHORT TERM UPDATE... Forecast looks on track for tonight and Wednesday, so no updates are anticipated this evening. && .PREV DISCUSSION... Issued at 344 PM HST Tue Aug 18 2026 The return of the trade winds will bring areas of showers over windward and mauka locations through tonight. Trades weaken Wednesday through Friday as a trough passes northeast of the islands. Lighter trades will increase precipitation chances for leeward areas with the development of a sea/land breeze pattern. The winds are expected to strengthen and shift easterly late Friday into Saturday, which will pull additional moisture into the area. This will increase precipitation chances for early in the weekend. Highest chances will be on the windward and mauka parts of the islands. For Sunday and Monday, tropical moisture is expected to be in the vicinity of the state due to the potential development of a tropical system. Most guidance keeps the track of the potential tropical system south of the islands. While there remains uncertainty in the forecast since the system has yet to develop, precipitation chances have been increased for early next week. Please continue to monitor the forecast as it is subject to change as we get closer to the weekend and details surrounding the forecast become clearer. && .AVIATION... Moderate trades expected through tomorrow. Some windward and mauka SHRA possible with isol MVFR conds. VFR conditions should prevail. No AIRMETs are currently in effect. && .MARINE... High pressure far northeast of the waters will remain nearly stationary and slowly weaken for the next couple of days. Trade winds will continue a weakening trend, becoming light and variable for most waters by Thursday as daytime sea breezes and overnight land breezes become established. By late Friday, moderate to locally fresh trades will begin to build back into the region as the high drifts southward closer to the island chain. Heading into the weekend, the potential development of a tropical system southeast of the islands is possible but uncertainty remains as the system has yet to develop. Surf along south facing shores will continue declining through midweek as south swell fades. Another long period south swell generated from gales just south and east of New Zealand will begin arriving late this week. Surf along east facing shores will also continue to fade as background flow becomes weaker. North facing shores will remain tiny throughout the week. && .FIRE WEATHER... Issued at 340 PM HST Tue Aug 18 2026 Moderate trade winds will prevail through tonight. Trade winds will weaken Wednesday through Friday, increasing chances of showers for the leeward side of the islands. Trade winds increase over the weekend into early next week with increased chances of precipitation. The inversion is 6000 to 7000 ft. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM UPDATE...Foster PREVIOUS DISCUSSION...CO AVIATION...Walsh MARINE...Vaughan