Alert archive / Montana

Weather alerts in Glacier County, Montana

1,567 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Glacier County and its neighbors

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

Alerts
1,567
Warnings
558
Watches
342
Advisories
250
Busiest year
2025161 alerts
Average year
44over 36 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.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20089367%1100%16 min
20093167%1100%4 min
20107357%667%12 min
20112150%520%26 min
201214564%1527%14 min
2013181044%2250%15 min
20142150%250%20 min
2015010%
20167271%333%45 min
20175260%30%
2018220%1100%18 min
2019220%450%37 min
2020030%
202110370%1040%13 min
2022201050%2483%28 min
20234175%250%7 min
202411373%1100%18 min
20253233%714%1 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2009010%
202310100%10%

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 2, 4:26 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX79 min
Jul 31, 1:11 PM MDTRed Flag WarningMSO56 hr
Jul 31, 12:06 PM MDTHigh Wind WarningTFX48 hr
Jul 31, 11:01 AM MDTRed Flag WarningTFX64 hr
Jul 23, 1:57 PM MDTRed Flag WarningTFX55 hr
Jul 16, 7:02 PM MDTSevere Thunderstorm WarningTFX44 min
Jun 30, 4:30 PM MDTAreal Flood WarningTFX20 hr
Jun 29, 9:17 PM MDTAreal Flood WarningTFX19 hr
Jun 29, 8:41 PM MDTAreal Flood WarningTFX20 hr
Jun 29, 1:05 PM MDTAreal Flood WarningTFX27 hr
Jun 16, 12:13 AM MDTHigh Wind WarningTFX21 hr

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.