Alert archive / Missouri / Vernon County

Flash Flood Warnings in Vernon County, Missouri

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

Vernon County and its neighbors

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

Flash Flood Warnings
243
Busiest year
200923 flash flood warnings
Average year
7over 37 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, 91% of flash flood reports in Vernon County fell inside a flash flood warning issued on average 206 minutes before, and 38% of the flash flood warnings had no report inside them.

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008211433%1283%332 min
2009231917%989%149 min
201014750%8100%264 min
20114175%0
20126433%8100%260 min
20139811%683%154 min
20144250%0
20156350%1100%237 min
20164250%0
2017440%4100%75 min
201810100%0
2019151033%2100%36 min
202030100%0
20217186%1100%1 min
20222150%0
202320100%0
20247614%4100%178 min
20254325%367%62 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
Jun 8, 3:15 AM CDTFlash Flood WarningSGF6 hr
Apr 17, 5:37 PM CDTFlash Flood WarningSGF6 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.