Alert archive / Hawaii / Maui County

Flash Flood Warnings in Maui County, Hawaii

207 flash flood warnings since 1986. An alert counts here when it covered this county. The archive of flash flood warnings reaches back to 1986.

Maui County and its neighbors

Each county as a circle sized by its count since 1986. Tap one for its archive.

Flash Flood Warnings
207
Busiest year
200623 flash flood warnings
Average year
9over 23 years on file

Over time

By year

Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with the weather.

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

From 2008 to 2025, 59% of flash flood reports in Maui County fell inside a flash flood warning issued on average 145 minutes before, and 70% of the flash flood warnings had no report inside them.

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20087186%0
200920100%0
201060100%0
20118538%367%122 min
20126350%1100%60 min
201311645%875%108 min
201490100%30%
201516475%1759%126 min
201612467%1625%73 min
201712375%888%170 min
201818667%978%174 min
20192150%1100%149 min
202030100%20%
202116756%1267%239 min
20226267%580%107 min
20236183%367%57 min
20247186%560%161 min
20254175%367%125 min

Years from 2008, the first full year of storm-based warnings. The year still running is on its own page.

Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.

The latest flash flood warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Aug 16, 11:50 AM HSTFlash Flood WarningHFO4 hr
Aug 16, 2:07 AM HSTFlash Flood WarningHFO3 hr
Apr 12, 5:22 PM HSTFlash Flood WarningHFO2 hr
Apr 7, 6:57 PM HSTFlash Flood WarningHFO5 hr
Mar 24, 12:58 AM HSTFlash Flood WarningHFO8 hr
Mar 22, 6:06 AM HSTFlash Flood WarningHFO5 hr
Mar 21, 10:35 PM HSTFlash Flood Warning Considerable damage threatHFO5 hr
Mar 21, 11:57 AM HSTFlash Flood WarningHFO12 hr
Mar 21, 11:32 AM HSTFlash Flood WarningHFO5 hr
Mar 21, 9:34 AM HSTFlash Flood WarningHFO6 hr
Mar 20, 11:34 PM HSTFlash Flood Warning Considerable damage threatHFO3 hr
Mar 14, 3:53 PM HSTFlash Flood WarningHFO7 hr

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive

Sources

National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.