Alert archive / Colorado / Larimer County / Flash Flood Warnings

Flash Flood Warnings in Larimer County, Colorado, 2014

15 flash flood warnings in 2014. 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 2014. Tap one for its archive.

Flash Flood Warnings
15
Busiest month
July10 flash flood warnings
Busiest day
July 29, 20145 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.

6 of 15 flash flood warnings covering Larimer County in 2014 had a flash flood report inside them; 7 of 10 flash flood reports fell inside a warning, on average 26 minutes after it went out.

Larimer County, 2014

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Flash flood warnings15660%1070%26 min

Each office's whole area, 2014

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Denver/Boulder, CO: flash flood warnings41978%2259%33 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
May 23, 7:21 PM MDTFlash Flood WarningBOU3 hr
May 23, 8:10 PM MDTFlash Flood WarningBOU3 hr
May 25, 2:19 PM MDTFlash Flood WarningBOU2 hr
Jun 24, 11:03 PM MDTFlash Flood WarningBOU2 hr
Jul 13, 6:09 PM MDTFlash Flood WarningBOU96 min
Jul 14, 7:49 PM MDTFlash Flood WarningBOU116 min
Jul 14, 8:19 PM MDTFlash Flood WarningBOU2 hr
Jul 15, 3:17 PM MDTFlash Flood WarningBOU118 min
Jul 28, 1:22 PM MDTFlash Flood WarningBOU3 hr
Jul 29, 12:20 PM MDTFlash Flood WarningBOU3 hr
Jul 29, 1:36 PM MDTFlash Flood WarningBOU3 hr
Jul 29, 2:44 PM MDTFlash Flood WarningBOU6 hr
Jul 29, 3:16 PM MDTFlash Flood WarningBOU3 hr
Jul 29, 5:05 PM MDTFlash Flood WarningBOU6 hr
Aug 26, 4:08 PM MDTFlash Flood WarningBOU2 hr

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20132015

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.