textproduct: Honolulu

SYNOPSIS

Light showers are possible through this evening. Trade wind pattern returns Tuesday with windward and mauka showers much of this week. Precipitation chances increase Friday and Saturday for windward areas. Winds may veer southeasterly late in the week.

SHORT TERM UPDATE

A more seasonal trade wind shower pattern returns tonight. Expect relatively drier conditions for the first half of the week, with lighter winds and increased trade wind precipitation during the latter half.

PREV DISCUSSION

Issued at 344 PM HST Mon Aug 17 2026

Scattered, light showers will diminish this evening. Over the past 12 hours an additional 0.20 to 0.60 inches of rain has fallen across the state, with some locally higher accumulations. For the middle of the week, the atmosphere will gradually dry out in the wake of Tropical Storm Lala. Moderate strength winds will prevail for the first half of the week, becoming light by Thursday. The return of the trade winds will maintain scattered showers over windward and mauka locations, with isolated spill over into leeward areas.

For late Thursday through the weekend the trades will veer east- southeast, pulling additional moisture into the area. This will increase precipitable water values for Friday and Saturday. Due to the expected moisture increase, precipitation chances have been increased for Friday into Saturday, especially for windward areas. A subtle drying is expected on Sunday.

For early next week, there is quiet a bit of difference between the GFS and the ECMWF. The GFS supports a wetter pattern with the ECMWF on the drier side. Current forecast maintains drier conditions, which may need adjusting in the coming days depending on how the pattern develops.

AVIATION

Moderate trades through the forecast period. Low cigs and SHRA along windward and mauka locations. MVFR conds possible in SHRA otherwise VFR prevails.

AIRMET Sierra is in effect for mtn obsc along windward portions of all islands. Conds should improve in the mid morning hours.

MARINE

With Tropical Storm Lala now well west of the islands, fresh to locally strong easterly trade winds have filled in across the entire coastal waters. A Small Craft Advisory (SCA) remains in effect for the windier waters and channels around Maui County and the Big Island through tonight, but trade winds will gradually ease dropping into the moderate to locally fresh range by Tuesday. During the second half of the week, trades will weaken further to become light and variable for most waters before strengthening again this weekend.

Surf along south facing shores remains elevated from a moderate, medium to long period swell that has peaked and plateaued this evening. Observations at PacIOOS buoy Barber's Point shows the south swell maintaining at roughly 4 feet, 14 seconds through tonight. However, it is still expected to slowly decline through midweek, so the overall trend remains unchanged. Some wrap also continues this evening for west facing shores, but this is also expected to follow suit as the south swell declines. 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 continue to fade tonight as Lala moves further west away from the state and as trades decrease on Tuesday. North facing shores will remain tiny throughout the week.

FIRE WEATHER

Issued at 344 PM HST Mon Aug 17 2026 Moderate relatively moist trade winds will prevail through mid- week. Winds will weaken Thursday and Friday with increasing humidity. Trade winds increase over the weekend with minor changes in humidity. No fire weather concerns through the forecast period. There is no temperature inversion.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 AM HST Tuesday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.