In the big picture, two surface low pressure systems will continue move slowly northeastward through the northern Hawaii region into the weekend, producing additional periods of moderate to heavy rain, thunderstorms, and elevated threats for flash flooding. A combination of low level forcing and passing upper level troughs will drive these smaller scale heavy rain band and thunderstorm formations. Additional weather threats include strengthening south to southwest Kona winds on Saturday that will produce down sloping wind gusts in the 30 to 45 MPH range along steep north and east slopes of island mountain ranges lasting through Saturday night. Improving weather trends will develop from west to east on Monday as we transition to a wet trade wind weather pattern lasting through the end of next week.
Bands of rain with embedded heavy showers and storms are expected to continue over Oahu and Maui County through the night. These rainbands are producing periods of IFR to LIFR CIGS/VSBYS, which will persist into the weekend as an upper level trough approaches from the west. Kauai and Big Island are expected to be mostly VFR through tonight, with MVFR conditions possible within an occasional shower.
Low-level winds continue to be out of the S-SSW, and may veer more SW over the western half of the state on Saturday. Winds are strongest over Maui county, with gusts reported up to 39 kt at PHOG. These winds may result in localized mechanical turbulence leeward of terrain. Winds will remain gusty through the evening, but gradually weaken through the weekend.
AIRMET Sierra for mountain obscuration is in effect across all islands except Kauai and the Big Island, and will likely continue into the weekend. AIRMET Tango is in effect for moderate turbulence downwind of terrain for Oahu and Maui county below 090. AIRMET Zulu for light icing in the 140-FL260 layer will continue to be a concern within deeper cloud layers associated with the upper level disturbance.
Issued at 342 PM HST Fri Mar 20 2026
Light to moderate S winds may strengthen tonight as surface low pressure west of Kauai deepens. Moderate to locally strong S/SW prevail through Saturday, and periods of heavy showers and thunderstorms are expected. The low will lift north on Sunday allowing moderate N winds to develop around Kauai which will then veer to NE and spread south. Fresh to strong NE winds may require a Small Craft Advisory over most waters.
N swell will increase into Saturday in maintenance of moderate swell through the weekend along N facing shores. A small, overlapping WNW swell then arrives late Saturday and holds through Monday. Surf along E shores remain well below average through the weekend. NE trades then develop early next bringing increase NE fresh swell and an increase in short period choppy surf which may approach the High Surf Advisory threshold.
A moderate S swell slowly diminishes through today followed by a small reinforcing SSW swell this weekend into Monday. Smaller surf is expected along south facing shores through the remainder of the week.
Flood Watch through Sunday afternoon for all Hawaiian Islands.
Winter Storm Watch from Saturday evening through Sunday afternoon for Big Island Summits.
