Alert archive / Montana

Weather alerts in Fergus County, Montana

2,803 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Fergus County and its neighbors

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

Alerts
2,803
Warnings
994
Watches
405
Advisories
238
Busiest year
2025257 alerts
Average year
70over 40 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, 100% of tornado reports in Fergus County fell inside a tornado warning issued on average 42 minutes before, and 80% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200820100%0
20124250%1100%42 min
201310100%0
201620100%0
20194175%0
202020100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008241346%1681%14 min
200913654%944%17 min
201011918%10100%26 min
201111555%1385%20 min
20128450%450%21 min
2013201050%1362%29 min
201410550%475%12 min
20154175%10%
2016402050%5679%28 min
201720100%50%
201819668%1681%20 min
2019311358%2361%15 min
202015660%1553%18 min
202114657%1080%14 min
202229776%1155%27 min
202314657%1060%23 min
202414750%850%19 min
2025531964%4360%26 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
201110100%10%
2018010%
20233233%2100%111 min
202520100%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 13, 11:52 PM MDTHigh Wind WarningTFX18 hr
Sep 13, 9:02 PM MDTSevere Thunderstorm WarningTFX43 min
Sep 6, 11:28 PM MDTSevere Thunderstorm WarningTFX47 min
Sep 6, 10:26 PM MDTSevere Thunderstorm WarningTFX64 min
Sep 6, 10:24 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX31 min
Sep 6, 9:54 PM MDTSevere Thunderstorm WarningTFX36 min
Sep 6, 9:08 PM MDTSevere Thunderstorm WarningTFX82 min
Sep 6, 8:29 PM MDTSevere Thunderstorm WarningTFX46 min
Sep 6, 8:05 PM MDTSevere Thunderstorm WarningTFX40 min
Sep 6, 7:10 PM MDTSevere Thunderstorm WarningTFX50 min
Sep 6, 6:40 PM MDTSevere Thunderstorm WarningTFX20 min
Sep 6, 6:36 PM MDTSevere Thunderstorm WarningTFX39 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.