Hawaii Flood Watch | Effective 05/15/2026 04:35

Headline: 
Flood Watch issued May 15 at 1:35AM HST until May 15 at 6:00PM HST by NWS Honolulu HI
Event: 
Flood Watch
Urgency: 
Future
Effective: 
May 15, 2026 - 4:35am
Expires: 
May 15, 2026 - 9:00pm
Description: 
...FLOOD WATCH IN EFFECT THROUGH THIS AFTERNOON FOR MOST HAWAIIAN ISLANDS... * WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...Niihau, Kauai, Oahu, Molokai, Lanai, Kahoolawe, and Maui. * WHEN...Through this afternoon. * IMPACTS...Flood prone roads and other low lying areas may be closed due to elevated runoff and overflowing streams. Urban areas may receive more significant flooding and property damage due to rapid runoff. * ADDITIONAL DETAILS... - An unseasonably cold upper level low moving into the Hawaiian Islands from the north will produce periods of heavy showers across the island chain today. The center of the low will settle in over Kauai around noon HST, the low will then weaken and drift slowly eastward tonight. Unstable conditions within this upper low will likely produce periods of thunderstorms and heavy showers, potentially leading to flash flooding conditions in some areas. This Flood Watch may need to be extended into the overnight hours for some counties.
Instruction: 
You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.
Area Description: 
Niihau; Kauai Southwest; Kauai Mountains; Waianae Coast; Oahu North Shore; Olomana; Central Oahu; Waianae Mountains; Lanai Mauka; Kahoolawe; Maui Windward West; Maui Leeward West; Haleakala Summit; Kauai North; Kauai East; Kauai South; East Honolulu; Honolulu Metro; Ewa Plain; Koolau Windward; Koolau Leeward; Molokai Windward; Molokai Southeast; Molokai North; Molokai West; Molokai Leeward South; Lanai Windward; Lanai Leeward; Lanai South; Maui Central Valley North; Maui Central Valley South; Windward Haleakala; Kipahulu; South Maui/Upcountry; South Haleakala
Forcast Office: 
NWS Honolulu HI
Sender: 
w-nws.webmaster@noaa.gov