Alert archive / Montana

Weather alerts in Chouteau County, Montana

2,343 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Chouteau County and its neighbors

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

Alerts
2,343
Warnings
927
Watches
332
Advisories
250
Busiest year
2025194 alerts
Average year
57over 41 years on file

Over time

By year

Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.

By month of the year

Warning verification

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

From 2008 to 2025, 33% of tornado reports in Chouteau County fell inside a tornado warning issued on average 4 minutes before, and 88% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200820100%30%
20126267%2100%4 min
201560100%0
201610100%0
2018010%
201910100%0
202510100%0
Share of tornado reports inside a tornado warning, by year.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008241442%1164%20 min
200920955%1377%20 min
201014137%7100%20 min
201118950%757%15 min
2012231630%1593%33 min
2013302130%1369%30 min
2014131023%1656%23 min
20158275%863%14 min
2016351751%786%13 min
201710730%956%22 min
201811373%10%
2019291838%9100%19 min
202012925%1080%17 min
20218625%771%9 min
2022381658%838%11 min
202312375%0
2024311552%683%30 min
2025341750%956%18 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
201110100%0
201610100%0
201830100%0
202320100%0
20252150%0

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.

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The latest warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Sep 25, 2:54 AM MDTHigh Wind WarningTFX33 hr
Sep 13, 9:28 PM MDTSevere Thunderstorm WarningTFX47 min
Sep 13, 9:02 PM MDTSevere Thunderstorm WarningTFX43 min
Sep 6, 9:02 PM MDTSevere Thunderstorm WarningTFX58 min
Sep 6, 8:05 PM MDTSevere Thunderstorm WarningTFX40 min
Sep 6, 7:54 PM MDTSevere Thunderstorm WarningTFX29 min
Sep 6, 7:10 PM MDTSevere Thunderstorm WarningTFX50 min
Sep 6, 6:53 PM MDTSevere Thunderstorm WarningTFX52 min
Sep 6, 6:36 PM MDTSevere Thunderstorm WarningTFX39 min
Sep 2, 4:26 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX79 min
Sep 2, 4:13 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX62 min
Sep 2, 3:59 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX61 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.