Alert archive / Montana / Gallatin County

Weather alerts in Gallatin County, Montana, 2021

100 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Gallatin County and its neighbors

Each county as a circle sized by its count in 2021. Tap one for its archive.

Alerts
100
Warnings
32
Watches
12
Advisories
5
Busiest month
July31 alerts
Busiest day
July 22, 20219 alerts

Over time

By month

Warning verification

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

Gallatin County, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings8450%1527%5 min
Flash flood warnings010%

Each office's whole area, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Great Falls, MT: tornado warnings10100%10%
NWS Great Falls, MT: severe thunderstorm warnings652758%9641%12 min
NWS Great Falls, MT: flash flood warnings10100%40%

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 3, 4:07 PM MSTSpecial Weather StatementTFX23 min
Jan 13, 10:48 AM MSTSpecial Weather StatementTFX57 min
Jan 13, 11:08 AM MSTSpecial Weather StatementTFX67 min
Jan 13, 6:50 PM MSTAreal Flood AdvisoryTFX48 hr
Jan 15, 6:54 PM MSTAreal Flood AdvisoryTFX4 days
Feb 15, 11:04 PM MSTAreal Flood AdvisoryTFX33 hr
Mar 10, 5:33 PM MSTSpecial Weather StatementTFX57 min
Mar 27, 2:37 AM MDTRed Flag WarningTFX41 hr
Mar 31, 2:39 PM MDTRed Flag WarningTFX30 hr
May 7, 2:25 PM MDTMesoscale DiscussionSPC2 hr
May 7, 2:32 PM MDTSpecial Weather StatementTFX88 min
May 7, 4:21 PM MDTSpecial Weather StatementTFX24 min
Jun 4, 1:59 PM MDTMesoscale DiscussionSPC2 hr
Jun 4, 5:32 PM MDTSpecial Weather StatementTFX28 min
Jun 4, 9:30 PM MDTSevere Thunderstorm WarningTFX33 min
Jun 4, 9:36 PM MDTSpecial Weather StatementTFX24 min
Jun 5, 2:27 PM MDTMesoscale DiscussionSPC2 hr
Jun 14, 9:26 AM MDTRed Flag WarningBYZ43 hr
Jun 14, 9:56 AM MDTRed Flag WarningTFX38 hr
Jul 3, 5:37 PM MDTSpecial Weather StatementTFX38 min
Jul 3, 9:56 PM MDTSpecial Weather StatementTFX34 min
Jul 4, 5:48 PM MDTSpecial Weather StatementTFX42 min
Jul 4, 6:26 PM MDTSevere Thunderstorm WarningTFX19 min
Jul 4, 6:34 PM MDTSpecial Weather StatementTFX26 min
Jul 4, 6:44 PM MDTSevere Thunderstorm WarningTFX16 min
Jul 4, 7:01 PM MDTSpecial Weather StatementTFX44 min
Jul 5, 6:29 PM MDTSpecial Weather StatementTFX31 min
Jul 5, 7:04 PM MDTSpecial Weather StatementTFX26 min
Jul 7, 3:55 PM MDTSpecial Weather StatementTFX50 min
Jul 7, 4:30 PM MDTSevere Thunderstorm WarningTFX30 min
Jul 7, 4:36 PM MDTSevere Thunderstorm WarningTFX15 min
Jul 11, 12:33 AM MDTRed Flag WarningTFX20 hr
Jul 14, 1:32 PM MDTRed Flag WarningTFX31 hr
Jul 18, 1:58 PM MDTRed Flag WarningTFX31 hr
Jul 18, 3:10 PM MDTRed Flag WarningBYZ57 hr
Jul 20, 4:21 PM MDTSpecial Weather StatementTFX24 min
Jul 20, 4:24 PM MDTSpecial Weather StatementTFX36 min
Jul 21, 1:26 PM MDTFire Weather WatchTFX25 hr
Jul 21, 1:26 PM MDTRed Flag WarningTFX56 hr
Jul 21, 1:39 PM MDTFire Weather WatchBYZ24 hr
Jul 21, 9:44 PM MDTSpecial Weather StatementTFX31 min
Jul 22, 1:40 PM MDTRed Flag WarningBYZ31 hr
Jul 22, 2:01 PM MDTSpecial Weather StatementTFX29 min
Jul 22, 2:13 PM MDTSevere Thunderstorm WarningTFX32 min
Jul 22, 2:24 PM MDTSpecial Weather StatementTFX66 min
Jul 22, 3:30 PM MDTSpecial Weather StatementTFX30 min
Jul 22, 3:32 PM MDTSpecial Weather StatementTFX28 min
Jul 22, 4:06 PM MDTSpecial Weather StatementTFX39 min
Jul 22, 4:40 PM MDTSpecial Weather StatementTFX35 min
Jul 23, 8:58 PM MDTFire Weather WatchTFX29 hr
Aug 2, 1:06 PM MDTSpecial Weather StatementTFX24 min
Aug 2, 2:22 PM MDTSpecial Weather StatementTFX23 min
Aug 2, 2:53 PM MDTAreal Flood AdvisoryTFX2 hr
Aug 2, 2:56 PM MDTSpecial Weather StatementTFX49 min
Aug 2, 3:52 PM MDTSpecial Weather StatementTFX38 min
Aug 2, 4:40 PM MDTAreal Flood AdvisoryTFX2 hr
Aug 4, 2:35 PM MDTRed Flag WarningTFX33 hr
Aug 5, 4:07 PM MDTSpecial Weather StatementTFX38 min
Aug 5, 4:23 PM MDTSpecial Weather StatementTFX52 min
Aug 6, 2:21 PM MDTFire Weather WatchTFX20 hr
Aug 7, 3:06 AM MDTFire Weather WatchBYZ11 hr
Aug 7, 10:48 AM MDTRed Flag WarningTFX33 hr
Aug 7, 2:26 PM MDTRed Flag WarningBYZ34 hr
Aug 8, 1:26 PM MDTSpecial Weather StatementTFX79 min
Aug 8, 2:37 PM MDTSpecial Weather StatementTFX83 min
Aug 8, 4:03 PM MDTSpecial Weather StatementTFX57 min
Aug 8, 4:29 PM MDTSevere Thunderstorm WarningTFX61 min
Aug 8, 6:45 PM MDTSpecial Weather StatementTFX45 min
Aug 8, 9:17 PM MDTSpecial Weather StatementTFX28 min
Aug 9, 2:58 AM MDTFire Weather WatchBYZ10 hr
Aug 14, 3:08 AM MDTFire Weather WatchBYZ11 hr
Aug 14, 3:39 AM MDTFire Weather WatchTFX11 hr
Aug 14, 2:07 PM MDTRed Flag WarningBYZ3 days
Aug 14, 2:40 PM MDTRed Flag WarningTFX54 hr
Aug 14, 4:10 PM MDTSpecial Weather StatementTFX35 min
Aug 16, 2:49 PM MDTMesoscale DiscussionSPC116 min
Aug 17, 2:21 PM MDTMesoscale DiscussionSPC114 min
Aug 17, 3:33 PM MDTSpecial Weather StatementTFX57 min
Aug 17, 4:51 PM MDTSpecial Weather StatementTFX54 min
Aug 30, 5:57 PM MDTSpecial Weather StatementTFX63 min
Sep 4, 2:20 PM MDTFire Weather WatchBYZ24 hr
Sep 4, 2:36 PM MDTRed Flag WarningTFX30 hr
Sep 5, 2:10 AM MDTFire Weather WatchTFX18 hr
Sep 5, 2:29 PM MDTRed Flag WarningBYZ30 hr
Sep 5, 3:21 PM MDTRed Flag WarningTFX30 hr
Sep 7, 2:32 PM MDTFire Weather WatchTFX22 hr
Sep 8, 12:57 PM MDTRed Flag WarningTFX32 hr
Sep 9, 5:46 PM MDTSpecial Weather StatementTFX29 min
Sep 9, 6:57 PM MDTSpecial Weather StatementTFX48 min
Sep 10, 5:46 PM MDTSpecial Weather StatementTFX29 min
Sep 10, 6:12 PM MDTSevere Thunderstorm Warning Considerable damage threatTFX48 min
Sep 10, 7:02 PM MDTSpecial Weather StatementTFX28 min
Sep 14, 1:04 PM MDTRed Flag WarningBYZ31 hr
Sep 16, 1:53 PM MDTRed Flag WarningBYZ55 hr
Sep 16, 2:18 PM MDTRed Flag WarningTFX55 hr
Sep 26, 2:41 AM MDTFire Weather WatchBYZ10 hr
Sep 26, 12:59 PM MDTRed Flag WarningBYZ32 hr
Oct 4, 9:14 AM MDTRed Flag WarningTFX35 hr
Nov 4, 7:35 PM MDTSpecial Weather StatementTFX40 min
Nov 11, 12:28 PM MSTSpecial Weather StatementTFX77 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 archive20202022

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.