Flash Flood Warnings in Washington County, Utah, 2013

By month

16 of 34 flash flood warnings covering Washington County in 2013 had a flash flood report inside them; 20 of 30 flash flood reports fell inside a warning, on average 81 minutes after it went out.

Washington County, 2013

Each office's whole area, 2013

An office's figures cover every county it serves, including across state lines.

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.

1. August 31, 20135flash flood warnings
2. September 11, 20135flash flood warnings
3. July 19, 20132flash flood warnings
4. July 26, 20132flash flood warnings
5. July 28, 20132flash flood warnings
6. August 24, 20132flash flood warnings
7. August 25, 20132flash flood warnings
8. September 15, 20132flash flood warnings
9. July 11, 20131flash flood warnings
10. July 12, 20131flash flood warnings

Alerts in force nowTornadoes on recordForecastThe radar archive20122014

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.