An unstable and somewhat wet trade wind pattern will continue through Tuesday night, with brief downpours possible. From Wednesday into early next week, an area of high pressure north of the islands will push drier air the region and strengthen winds. The result will be a moderate to breezy trade wind pattern.
Issued at 840 PM HST Mon May 18 2026
Moderate to locally breezy trades expected hold for the next couple days. Low cigs and SHRA will primarily impact windward and mauka locations with some limited spillover to leeward areas. MVFR conds possible in heavier SHRA, otherwise VFR prevails.
AIRMET Sierra is in effect for mtn obsc for windward Kauai, Maui and the entire area of the Big Island.
Issued at 840 PM HST Mon May 18 2026
The pressure gradient back from a surface high centered about 1,500 nautical miles northeast of the islands remains tight enough to support moderate to locally fresh trades the next couple of days. The anchored high will expand and strengthen through mid to late week. The resultant very tight gradient back across the Central Pacific will produce fresh to locally strong to near gale force nearshore winds the later half of the week. A Small Craft Advisory (SCA) is currently in effect over the windier zones surrounding Maui County and Big Island. The SCA will likely be expanded in area later this week to account for more areawide strengthened trades.
A small size, short to medium period north northwest swell is expected to fill in overnight into Tuesday. A gale low skirting the Aleutian Islands the next couple of days will send the tail ends of small north northwest swells through late this week.
A series of small, long period south southwest swells will provide near summer average size surf along south-facing shores throughout the week. Strengthening trades later this week will keep short period, elevated eastern wind wave chop alive well into the weekend.
Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
