A high pressure system will remain far north of the Hawaiian Islands will keep trade winds in the moderate to locally windy range through Tuesday. A low level trough passing through the islands tonight will keep enhanced showers in the forecast favoring the windward mountain slopes of Maui and the Big Island in the overnight to early morning hours. Medium range model solutions are showing a deepening low setting up just north of the island chain from Thursday onward, potentially increasing shower activity from Friday into the weekend.
Breezy trades. Isolated to scattered showers, concentrated mainly along windward and mauka locations, most numerous late at night through the mornings. Showers may produce brief periods of MVFR ceilings and visibility.
AIRMET Sierra remains in effect for north through east sections of the Big Island and Maui above 2500 feet due to low clouds and showers.
AIRMET Tango remains in effect for for tempo moderate turbulence downwind of terrain below 9000 ft.
Issued at 308 PM HST Sun Oct 18 2026 Robust surface high pressure centered far north of Hawaii will maintain fresh to strong trade winds at current strength for the next couple of days, and a Small Craft Advisory (SCA) remains in effect for all waters except windward Big Island through early Tuesday. Trades will steadily decrease late Tuesday and Wednesday as the high weakens and is displaced eastward by an approaching low far northwest of the islands. The SCA will likely be trimmed back to the typically windy waters around Big Island and Maui at that time. Trade winds will lower to gentle strength, or may become disrupted, as the low passes to the north Thursday and Friday.
A north-northwest swell and a smaller overlapping west-northwest swell will slowly decline through Monday and fade on Tuesday. A very small northwest swell may arrive Thursday, followed by a moderate north- northwest swell next weekend.
The current south swell will continue a slow decline over the next day or so. South shore surf will drop below seasonal average Monday and will remain relatively small through much of the week. A moderate south-southwest swell is expected next weekend.
Rough trade wind swell will produce east shore surf just above seasonal average through Tuesday, then decline later in the week as trade winds decrease.
Small Craft Advisory until 6 AM HST Tuesday for most Hawaiian coastal waters and channels.
