Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
755 FXHW60 PHFO 161908 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 908 AM HST Thu Jul 16 2026 .SYNOPSIS... Trade winds will gradually increase through tomorrow and will by locally breezy through most of the weekend. Winds will ease a bit early next week. Fairly typical summertime weather is expected through the week, with showers favoring windward and mauka areas. && .SHORT TERM UPDATE... Much of the passing trade wind showers are now focusing over windward and mountain areas of Kauai rather than the Big Island this morning. Other than that, no updates look necessary as a typical summertime trade wind pattern holds. && .PREV DISCUSSION... Issued at 326 AM HST Thu Jul 16 2026 Trade winds will back out of a more typical east-northeast direction and increase today. The local pressure gradient and resulting trades will strengthen as a mid-level trough moves away to the west and robust surface high pressure holds far northeast of the islands. A pocket of moisture moving along the trade wind flow will be focused over windward Big Island through the morning, with a lesser amount of shower activity expected on other windward slopes. A ridge aloft will maintain stable conditions that will limit shower intensity and keep windward rainfall totals on most islands less than a quarter of an inch today. Aside from scattered afternoon showers on the Kona slopes, leeward areas will experience little rainfall. Typical summertime trade wind weather will prevail Friday through the weekend. Trades will become locally breezy as the surface high remains parked to the northeast and broad areas of low pressure pass well south of the islands in the deep tropics. Stable and somewhat dry conditions will keep modest shower activity focused over windward areas. Trades will ease slightly late Sunday into the first half of next week. Little to no organized areas of moisture are seen in the guidance, suggesting continued mainly windward showers. && .AVIATION... Issued at 326 AM HST Thu Jul 16 2026 Moderate trades expected for next few days. Low cigs and SHRA will impact windward and mauka locations. MVFR conds possible in SHRA, otherwise VFR prevails. No AIRMETs in effect. && .MARINE... Issued at 326 AM HST Thu Jul 16 2026 High pressure far north of the islands and very broad weak troughing to the west is leading to a slightly veered and lighter trade wind flow across the coastal waters this morning. The pressure gradient is expected to strengthen today as the high pressure to the north dips south, causing an uptick in trade wind speeds by this afternoon and continuing through the weekend. As the trades gradually strengthen to fresh to strong levels today, a Small Craft Advisory has been issued for the windier channels and waters around Maui County and the Big Island through Friday afternoon. This will likely need to be extended through at least Saturday before weakening high pressure to the north allows winds to diminish again. A small, long-period west-northwest swell from former Super Typhoon Bavi will maintain similar surf heights along west-facing and north- facing shores today (as compared to yesterday) before gradually subsiding tonight into the weekend. This swell is overlapping for some west-facing shores with a gradually fading small, medium-period southwest Tasman swell that will produce somewhat below average surf for south-facing shores today. North-facing shores return to flat to tiny surf by this weekend with the loss of the west-northwest swell. Surf returns to near average for south-facing shores late Friday with a reinforcing small, long-period south-southwest swell. This swell then fades through the weekend. A moderate, long-period south swell will arrive Sunday and build through early next week, bringing the potential for above-average (though sub-advisory) surf. Surf along east-facing shores will be slightly below seasonal averages through Thursday with lighter trade winds, then climb back up a notch as trades strengthen through the weekend. Early to midweek next week, there`s potential for a small, long- to medium-period swell to arrive, generated from Tropical Storm Elida. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Friday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel. && $$ DISCUSSION...Wroe AVIATION...Walsh MARINE...Quesada