Alert archive / Montana / Beaverhead County

Severe Thunderstorm Warnings in Beaverhead County, Montana

133 severe thunderstorm warnings since 1986. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Beaverhead County and its neighbors

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

Severe Thunderstorm Warnings
133
Busiest year
202413 severe thunderstorm warnings
Average year
5over 27 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, 24% of hail, wind and damage reports in Beaverhead County fell inside a severe thunderstorm warning issued on average 22 minutes before, and 63% of the severe thunderstorm warnings had no report inside them.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200811645%978%32 min
20093233%729%33 min
201010100%30%
2011040%
2012060%
20137443%1040%21 min
2014010%
201510100%20%
2016060%
201710100%20%
201830100%40%
20199544%1354%14 min
2020020%
20213167%119%2 min
202280100%80%
20236350%520%33 min
202413562%1436%19 min
20257186%813%0 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 severe thunderstorm warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Sep 6, 4:31 PM MDTSevere Thunderstorm WarningTFX29 min
Sep 6, 4:04 PM MDTSevere Thunderstorm WarningTFX41 min
Sep 2, 1:33 PM MDTSevere Thunderstorm WarningTFX57 min
Jul 25, 4:06 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX33 min
Jul 18, 2:32 PM MDTSevere Thunderstorm WarningTFX28 min
Jul 16, 5:02 PM MDTSevere Thunderstorm WarningTFX58 min
Jul 16, 3:55 PM MDTSevere Thunderstorm WarningTFX36 min
Jul 15, 7:43 PM MDTSevere Thunderstorm WarningTFX26 min
May 13, 2:13 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX47 min

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.