Alert archive / Montana / Glacier County

Weather alerts in Glacier County, Montana, 2020

64 weather alerts in 2020, 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 in 2020. Tap one for its archive.

Alerts
64
Warnings
18
Watches
16
Advisories
2
Busiest month
June19 alerts
Busiest day
June 13, 20208 alerts

Over time

By month

Warning verification

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

Glacier County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings030%
Flash flood warnings00

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Great Falls, MT: tornado warnings20100%0
NWS Great Falls, MT: severe thunderstorm warnings652758%10844%14 min
NWS Great Falls, MT: flash flood warnings10100%0
NWS Missoula, MT: severe thunderstorm warnings7529%2969%12 min
NWS Billings, MT: severe thunderstorm warnings714142%14355%29 min
NWS Glasgow, MT: tornado warnings3233%2100%0 min
NWS Glasgow, MT: severe thunderstorm warnings794642%17474%25 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
Jan 30, 1:54 PM MSTFire Weather WatchTFX24 hr
Jan 31, 3:28 AM MSTRed Flag WarningTFX43 hr
Mar 4, 8:03 AM MSTSpecial Weather StatementTFX27 min
Apr 10, 10:33 PM MDTSpecial Weather StatementTFX117 min
May 31, 1:22 AM MDTAreal Flood AdvisoryTFX36 hr
May 31, 8:48 AM MDTSpecial Weather StatementTFX42 min
Jun 5, 10:24 PM MDTSpecial Weather StatementTFX21 min
Jun 5, 10:47 PM MDTSpecial Weather StatementTFX28 min
Jun 5, 11:10 PM MDTSpecial Weather StatementTFX35 min
Jun 6, 12:56 AM MDTSpecial Weather StatementTFX34 min
Jun 12, 8:40 PM MDTSpecial Weather StatementTFX50 min
Jun 13, 2:21 PM MDTMesoscale DiscussionSPC114 min
Jun 13, 2:59 PM MDTSpecial Weather StatementTFX61 min
Jun 13, 4:09 PM MDTSpecial Weather StatementTFX36 min
Jun 13, 4:29 PM MDTSpecial Weather StatementTFX31 min
Jun 13, 4:37 PM MDTSpecial Weather StatementTFX23 min
Jun 13, 5:29 PM MDTSpecial Weather StatementTFX46 min
Jun 13, 5:46 PM MDTSpecial Weather StatementTFX44 min
Jun 13, 6:11 PM MDTSpecial Weather StatementTFX34 min
Jun 13, 6:32 PM MDTSpecial Weather StatementTFX28 min
Jun 13, 7:03 PM MDTSpecial Weather StatementTFX42 min
Jun 24, 2:56 PM MDTSpecial Weather StatementTFX34 min
Jun 24, 4:28 PM MDTMesoscale DiscussionSPC62 min
Jun 24, 5:11 PM MDTSevere Thunderstorm WatchSPC5 hr
Jun 24, 8:40 PM MDTSpecial Weather StatementTFX35 min
Jul 7, 6:59 AM MDTSpecial Weather StatementTFX31 min
Jul 7, 7:15 AM MDTSpecial Weather StatementTFX30 min
Jul 7, 7:47 AM MDTSpecial Weather StatementTFX28 min
Jul 23, 3:56 AM MDTFire Weather WatchTFX24 hr
Jul 24, 3:32 AM MDTRed Flag WarningTFX17 hr
Aug 5, 3:01 PM MDTFire Weather WatchTFX23 hr
Aug 6, 2:23 PM MDTRed Flag WarningTFX31 hr
Aug 7, 12:42 AM MDTSpecial Weather StatementTFX33 min
Aug 9, 2:27 PM MDTFire Weather WatchTFX21 hr
Aug 10, 11:42 AM MDTRed Flag WarningTFX57 hr
Aug 16, 1:48 PM MDTFire Weather WatchTFX38 hr
Aug 17, 8:37 AM MDTRed Flag WarningTFX12 hr
Aug 18, 3:29 AM MDTRed Flag WarningTFX65 hr
Aug 19, 8:23 PM MDTRed Flag WarningTFX25 hr
Aug 21, 2:57 AM MDTFire Weather WatchTFX12 hr
Aug 21, 2:51 PM MDTRed Flag WarningTFX27 hr
Aug 27, 2:47 PM MDTFire Weather WatchMSO24 hr
Aug 28, 4:01 AM MDTFire Weather WatchTFX11 hr
Aug 28, 2:19 PM MDTRed Flag WarningMSO34 hr
Aug 28, 2:36 PM MDTRed Flag WarningTFX33 hr
Aug 30, 2:54 PM MDTFire Weather WatchTFX12 hr
Aug 31, 3:09 AM MDTRed Flag WarningTFX66 hr
Sep 3, 2:50 PM MDTFire Weather WatchTFX21 hr
Sep 4, 11:21 AM MDTFire Weather WatchTFX16 hr
Sep 4, 11:21 AM MDTRed Flag WarningTFX33 hr
Sep 4, 12:29 PM MDTRed Flag WarningMSO34 hr
Sep 12, 3:47 AM MDTFire Weather WatchTFX24 hr
Sep 13, 3:17 AM MDTRed Flag WarningTFX40 hr
Sep 22, 2:46 PM MDTFire Weather WatchTFX24 hr
Sep 23, 2:37 PM MDTRed Flag WarningTFX30 hr
Oct 2, 9:19 AM MDTFire Weather WatchTFX29 hr
Oct 3, 1:58 PM MDTRed Flag WarningTFX31 hr
Oct 6, 3:05 AM MDTRed Flag WarningTFX16 hr
Oct 6, 2:15 PM MDTFire Weather WatchTFX18 hr
Oct 7, 7:55 AM MDTRed Flag WarningTFX35 hr
Nov 5, 10:20 PM MSTAreal Flood AdvisoryTFX26 hr
Nov 7, 7:53 PM MSTMesoscale DiscussionSPC6 hr
Nov 7, 11:20 PM MSTSpecial Weather StatementTFX115 min
Nov 8, 4:47 AM MSTSpecial Weather StatementTFX118 min

By product

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

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20192021

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.