Alert archive / Colorado / Larimer County / Flash Flood Warnings

Flash Flood Warnings in Larimer County, Colorado, 2022

34 flash flood warnings in 2022. An alert counts here when it covered this county. The archive of flash flood warnings reaches back to 1986.

Larimer County and its neighbors

Each county as a circle sized by its count in 2022. Tap one for its archive.

Flash Flood Warnings
34
Busiest month
July18 flash flood warnings
Busiest day
July 7, 20223 flash flood warnings

Over time

By month

Warning verification

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

8 of 34 flash flood warnings covering Larimer County in 2022 had a flash flood report inside them; 11 of 15 flash flood reports fell inside a warning, on average 64 minutes after it went out.

Larimer County, 2022

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Flash flood warnings34876%1573%64 min

Each office's whole area, 2022

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Denver/Boulder, CO: flash flood warnings631773%3876%62 min

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.

The alerts

Every alert, in the order issued. Times are local, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Jun 3, 2:49 PM MDTFlash Flood WarningBOU107 min
Jun 16, 10:50 PM MDTFlash Flood WarningBOU3 hr
Jun 19, 2:41 PM MDTFlash Flood WarningBOU3 hr
Jul 3, 1:21 PM MDTFlash Flood WarningBOU3 hr
Jul 3, 1:59 PM MDTFlash Flood WarningBOU3 hr
Jul 5, 1:34 PM MDTFlash Flood WarningBOU3 hr
Jul 5, 1:43 PM MDTFlash Flood WarningBOU3 hr
Jul 6, 2:57 PM MDTFlash Flood WarningBOU3 hr
Jul 6, 6:50 PM MDTFlash Flood WarningBOU3 hr
Jul 7, 12:33 PM MDTFlash Flood WarningBOU3 hr
Jul 7, 2:54 PM MDTFlash Flood Warning Considerable damage threatBOU108 min
Jul 8, 6:32 PM MDTFlash Flood WarningBOU78 min
Jul 15, 3:52 PM MDTFlash Flood WarningBOU3 hr
Jul 15, 5:37 PM MDTFlash Flood WarningBOU2 hr
Jul 23, 3:15 PM MDTFlash Flood Warning Considerable damage threatBOU117 min
Jul 24, 2:23 PM MDTFlash Flood WarningBOU3 hr
Jul 27, 8:29 PM MDTFlash Flood Warning Considerable damage threatBOU3 hr
Jul 27, 8:37 PM MDTFlash Flood WarningBOU3 hr
Jul 28, 2:49 PM MDTFlash Flood WarningBOU3 hr
Jul 29, 12:50 PM MDTFlash Flood Warning Considerable damage threatBOU3 hr
Jul 31, 12:36 PM MDTFlash Flood WarningBOU3 hr
Aug 5, 1:56 PM MDTFlash Flood WarningBOU5 hr
Aug 5, 3:26 PM MDTFlash Flood WarningBOU3 hr
Aug 5, 4:18 PM MDTFlash Flood WarningBOU3 hr
Aug 7, 3:32 PM MDTFlash Flood WarningBOU3 hr
Aug 11, 2:37 PM MDTFlash Flood WarningBOU3 hr
Aug 13, 6:23 PM MDTFlash Flood WarningBOU3 hr
Aug 14, 12:02 PM MDTFlash Flood WarningBOU3 hr
Aug 14, 2:29 PM MDTFlash Flood WarningBOU3 hr
Aug 15, 2:13 PM MDTFlash Flood WarningBOU3 hr
Aug 15, 2:23 PM MDTFlash Flood WarningBOU3 hr
Aug 23, 3:20 PM MDTFlash Flood WarningBOU3 hr
Aug 23, 4:41 PM MDTFlash Flood WarningBOU3 hr
Aug 25, 12:15 PM MDTFlash Flood WarningBOU3 hr

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20212023

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.