Alert archive / Montana / Beaverhead County

Weather alerts in Beaverhead County, Montana, 2020

58 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Beaverhead County and its neighbors

Each county as a circle sized by its count in 2020. Tap one for its archive.

Alerts
58
Warnings
11
Watches
9
Advisories
0
Busiest month
August26 alerts
Busiest day
August 19, 20206 alerts

Over time

By month

Warning verification

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

Beaverhead County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings020%
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
Feb 23, 6:07 PM MSTSpecial Weather StatementTFX23 min
Feb 23, 6:35 PM MSTSpecial Weather StatementTFX25 min
Feb 23, 7:10 PM MSTSpecial Weather StatementTFX50 min
Apr 30, 5:17 PM MDTSpecial Weather StatementTFX28 min
May 18, 10:37 PM MDTSpecial Weather StatementTFX38 min
May 19, 1:36 PM MDTMesoscale DiscussionSPC114 min
May 19, 2:34 PM MDTSevere Thunderstorm WatchSPC7 hr
May 29, 2:12 PM MDTMesoscale DiscussionSPC2 hr
Jun 5, 1:46 PM MDTMesoscale DiscussionSPC119 min
Jun 6, 9:54 AM MDTSpecial Weather StatementTFX36 min
Jun 6, 3:52 PM MDTSpecial Weather StatementTFX23 min
Jun 6, 4:33 PM MDTSpecial Weather StatementTFX27 min
Jun 19, 7:53 AM MDTRiver Flood WarningTFX20 hr
Jun 24, 2:29 PM MDTMesoscale DiscussionSPC2 hr
Jun 24, 4:16 PM MDTSpecial Weather StatementTFX29 min
Jun 24, 5:17 PM MDTSpecial Weather StatementTFX28 min
Jul 9, 6:59 PM MDTSpecial Weather StatementTFX46 min
Jul 16, 2:06 PM MDTRed Flag WarningMSO30 hr
Jul 23, 11:39 AM MDTMesoscale DiscussionSPC2 hr
Jul 23, 2:43 PM MDTSevere Thunderstorm WatchSPC4 hr
Jul 23, 3:37 PM MDTSpecial Weather StatementTFX23 min
Jul 23, 4:04 PM MDTSpecial Weather StatementTFX26 min
Aug 3, 5:36 PM MDTMesoscale DiscussionSPC114 min
Aug 6, 1:53 PM MDTMesoscale DiscussionSPC2 hr
Aug 9, 1:57 PM MDTFire Weather WatchMSO21 hr
Aug 10, 11:22 AM MDTRed Flag WarningMSO58 hr
Aug 17, 12:28 PM MDTFire Weather WatchMSO20 hr
Aug 19, 2:34 PM MDTRed Flag WarningMSO31 hr
Aug 19, 2:45 PM MDTMesoscale DiscussionSPC2 hr
Aug 19, 3:05 PM MDTMesoscale DiscussionSPC115 min
Aug 19, 4:29 PM MDTSpecial Weather StatementTFX31 min
Aug 19, 4:53 PM MDTSpecial Weather StatementTFX37 min
Aug 19, 5:03 PM MDTSpecial Weather StatementTFX27 min
Aug 19, 6:34 PM MDTSpecial Weather StatementTFX26 min
Aug 19, 7:06 PM MDTSpecial Weather StatementTFX24 min
Aug 19, 7:46 PM MDTSpecial Weather StatementTFX29 min
Aug 21, 3:50 AM MDTFire Weather WatchMSO27 hr
Aug 22, 3:32 AM MDTRed Flag WarningMSO17 hr
Aug 25, 1:18 PM MDTMesoscale DiscussionSPC117 min
Aug 26, 2:44 PM MDTMesoscale DiscussionSPC91 min
Aug 26, 4:19 PM MDTSpecial Weather StatementTFX26 min
Aug 26, 5:58 PM MDTSpecial Weather StatementTFX32 min
Aug 26, 7:04 PM MDTMesoscale DiscussionSPC116 min
Aug 26, 10:18 PM MDTSpecial Weather StatementTFX57 min
Aug 27, 2:47 PM MDTFire Weather WatchMSO24 hr
Aug 27, 5:15 PM MDTSpecial Weather StatementTFX30 min
Aug 27, 6:01 PM MDTSpecial Weather StatementTFX29 min
Aug 28, 2:19 PM MDTRed Flag WarningMSO34 hr
Sep 3, 11:14 AM MDTFire Weather WatchMSO25 hr
Sep 4, 12:29 PM MDTRed Flag WarningMSO34 hr
Sep 12, 1:55 PM MDTFire Weather WatchMSO18 hr
Sep 13, 7:40 AM MDTRed Flag WarningMSO37 hr
Sep 16, 1:50 PM MDTFire Weather WatchMSO23 hr
Sep 17, 1:08 PM MDTRed Flag WarningMSO32 hr
Sep 19, 2:01 PM MDTSpecial Weather StatementTFX44 min
Sep 19, 3:04 PM MDTSpecial Weather StatementTFX56 min
Oct 9, 11:27 AM MDTRed Flag WarningMSO31 hr
Nov 4, 11:35 AM MSTRed Flag WarningMSO30 hr

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.