US National Weather Service Honolulu & Central Pacific Hurricane Center

27/03/2026

Event Review: Significant flooding occurred again across the Hawaiian Islands March 19-24, 2026.

A surface low pulled lingering deep tropical moisture that was over and just south of the Big Island from the recent kona storm back over the state. An upper trough provided instability and lift for clusters of heavy rainfall and thunderstorms with very intense rain rates. A slow-moving trough provided focus for low-level convergence to create nearly ideal conditions for flash flooding, especially from Oahu and points eastward. While the main atmospheric features of this event were weaker than the earlier kona storm and rainfall was less widespread, the impacts were more severe due to the already saturated ground–requiring less rainfall to result in runoff and rapid flooding.

View the attached photos to see some of the highest 6 day rainfall totals from each island during this event.

23/03/2026

Monday, March 23rd, 11:15am HST Radar Update: Thunderstorms with locally heavy rain are ongoing over portions of the Big Island and Maui. Thunderstorm chances will linger for these islands through this afternoon. Also of note, a few locally heavy showers are occurring along windward Oahu as well.

22/03/2026

Heavy rains across the state this month have caused terrible flooding. It has also resulted in a rainfall record for Kahului. The observation site is experiencing its wettest month ever recorded. And that's with 10 days left to go (the data currently go through the 21st).

Here's a chart showing the top 10 wettest months all time for Kahului. Note the 10 days missing this month...that's the remaining days in this month that will become available to add to the total. Also note that 13 days were missing from the 2nd-place month - Jan 1916. Severe flooding on Jan 18th of that year caused damage that made continuing to take measurements impossible...so we will never know what the actual total for that month would have been with complete data.

21/03/2026

Low level cloud band forming upstream (west to southwest) of Oahu this morning. Expect increasing shower trends for western and northern slopes of Oahu over the next few hours.

21/03/2026

A convergent cloud band with heavy showers and embedded thunderstorms slowly drifts eastward into Maui County. See latest GOES Infrared Satellite Loop.

Near real-time publication of GOES-East and GOES-West images from NOAA/NESDIS/STAR

21/03/2026

Heavy rain showers and thunderstorms moving eastward along a convergence band into Molokai this evening.

21/03/2026

A line of heavy showers and thunderstorms is developing south of Oahu and Maui County this evening. While the threat for flash flooding is possible across the state, the greatest risk area looks to be over Maui County and Oahu tonight. Due to the recent rain, the ground remains saturated, and it would only take minutes of intense rainfall to cause major flash flooding.

20/03/2026

Last information from Hawaii Department of Emergency management on the status of the Wahiawa Dam.

HNL Alert: 09:00 AM 03-20-2026 - WAHIAWA DAM HAS NOT FAILED BUT IS AT IMMINENT RISK OF FAILURE. Potential life-threatening flooding of downstream areas.

Evacuation order still in effect. Map: https://p.veoci.com/hnlevac LEAVE downstream area NOW! Heavy traffic-Please carpool

Details: https://alert.hnlalert.gov

20/03/2026

As of 1245 am HST Friday: Heavy rainfall is impacting the North Shore of Oahu tonight, where areas have already been dealing with recent flooding. Emergency managers are reporting drainage issues and standing water on roadways in Wailua where streams are running high. Do not drive through flooded roadways. Conditions can change quickly in the dark.

19/03/2026

Flood watch goes into effect tonight through Sunday for another kona low that is expected to bring widespread rain. Peak of the event will be Friday night to Saturday night. Saturated ground from last week's weather will bring potential for flooding even with less rain. Details: https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=HFO&wwa=flood%20watch

16/03/2026

Five days of storm total rainfall reports mapped across the Hawaiian Islands for the Kona Storm event through March 15th 2026.

16/03/2026

Highest wind gust reports for the recent Kona Storm affecting the Hawaiian Islands from March 13th through March 15th 2026.

PNS issued by NWS HFO at 16 Mar 2026 06:04 UTC