The Kona low continues to move rapidly towards the northeast away from the state and a high pressure system builds in quickly as the low departs. An upper level subtropical jet stream and deep unstable band of tropical moisture lingers over the Big Island today. This larger scale moisture band will drift eastward as high pressure builds in from the northwest, allowing more stabilizing trade winds to spread 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.
Issued at 909 AM HST Mon Mar 23 2026
Residual moisture associated with the departing Kona low continues to produce showers with embedded isolated thunderstorms over the eastern half of the state, particularly from Maui to the Big Island. Expect MVFR to isolated IFR conditions for Maui county and the Big Island, and VFR conditions for Kauai and Oahu. Trade winds have begun to reestablish over the western islands and are expected to gradually expand eastward across the state through the remainder of the forecast period.
AIRMET Sierra is in effect for N to E sections of Oahu, and for Maui, Molokai, and Lanai for the entire area due to showers and low clouds. Big Island could be added to this AIRMET later today as showers develop and move over the area. Light icing remains possible in layer 130-FL200 from Molokai through the Big Island.
SIGMET series November is in effect for the embedded thunderstorms near Maui and the Big Island.
Issued at 809 AM HST Mon Mar 23 2026
Bands of scattered showers continue to impact waters surrounding Maui County and Big Island. A boundary northwest of the island chain will travel southeast across the state today. 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 showers, as the upper trough passes east of the state Tuesday.
A small, short period north swell will gradually decline later today, while a small west-northwest persists. A reinforcing pulse of medium period north-northeast swell will arrive on Tuesday, peak in the afternoon and at night, then decline Wednesday. Surf along north and exposed east facing shores may near High Surf Advisory levels during the peak. Another small west-northwest swell will arrive Thursday, peak Friday, then decline during the weekend. Aside from areas along east shores exposed to the northerly swell, short period energy from rebuilding trade winds will increase to near seasonal average Tuesday night and Wednesday, then hold into the weekend. A small south- southwest swell will decline Tuesday and fade Wednesday. A short-lived pulse of small south- southeast swell will be possible Wednesday through Friday, and a small south- southwest swell could arrive Friday into the weekend.
Flood Watch until 6 PM HST this evening for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Kohala-Kona.
