The Kona low that produced significant heavy rain, thunderstorms and flash flooding over the Hawaiian Islands over the past four days continues to move rapidly towards the northeast away from the state. An upper level subtropical jet stream and deep unstable band of tropical moisture lingers over the eastern half of the state. This larger scale moisture band will drift eastward through Monday as high pressure builds in from the northwest, allowing more stabilizing trade winds to spread southeastward down the island chain. These cooler moderate to locally breezy trade winds will lower humidity levels and continue blowing across the islands through next weekend with passing showers favoring windward and mountain areas.
Residual moisture from the departing Kona low has left showers with embedded isolated thunderstorms across much of the Hawaiian Islands, namely from Oahu to the Big Island. Periods of MVFR conditions in these showers, with local LIFR conditions possible. Otherwise, first indication of trades have returned across the western islands and will spread across the state throughout the forecast period. VFR conditions prevail otherwise.
AIRMET Sierra is in effect for Lanai due to IFR in widespread low ceilings and showers and is expected to continue into tonight. AIRMET Sierra is also in effect for Oahu, Maui, Molokai, and the Big Island for mountain obscuration due to showers and low clouds. This is also expected to continue into tonight.
AIRMET Zulu remains for light icing in layer 140-FL260 will also persist, mainly over the central portion of the state where the thick high clouds continue to stream over from the southwest.
Issued at 319 PM HST Sun Mar 22 2026
Bands of scattered moderate to heavy showers, with an occasional embedded thunderstorm, moving in from the south will primarily impact those waters surrounding Maui County and Big Island. A boundary northwest of the island chain will travel southeast across the state through Monday. Gentle variable to southerly breezes downstream of this boundary will transition to strengthened north northeast winds behind the boundary passage. Moderate trades will become better established early this week, along with widely- scattered light showers, as the upper trough passes east of the state Tuesday.
The northeast swell that peaked yesterday will be on the decline through Monday. A small north swell will reinforce an already established background north swell Tuesday and Wednesday. This will maintain elevated north-facing shore surf the next few days. Very small south southwest swell will keep south-facing shore surf from going completely flat the remainder of the week. East surf will stay slightly elevated through Monday as result of a fading northeast swell and a little north wrap. East-facing shore short period wind waves will pick up at mid week in response to strengthened trades.
Flood Watch until 6 AM HST Monday for the Big Island of Hawaii.
Winter Storm Warning until 6 AM HST Monday for Big Island Summits of Mauna Kea and Mauna Loa.
