Alert archive / Montana / Pondera County

Weather alerts in Pondera County, Montana, 2021

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

Pondera County and its neighbors

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

Alerts
65
Warnings
21
Watches
9
Advisories
1
Busiest month
July24 alerts
Busiest day
July 21, 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.

Pondera County, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings40100%0
Flash flood warnings00

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, 12:29 PM MSTSpecial Weather StatementTFX61 min
Jan 27, 9:29 AM MSTSpecial Weather StatementTFX91 min
Feb 24, 7:24 AM MSTSpecial Weather StatementTFX36 min
Mar 10, 2:57 PM MSTSpecial Weather StatementTFX63 min
Mar 27, 2:37 AM MDTRed Flag WarningTFX41 hr
Mar 29, 6:14 AM MDTSpecial Weather StatementTFX61 min
Mar 29, 7:08 AM MDTSpecial Weather StatementTFX52 min
Mar 29, 8:02 AM MDTSpecial Weather StatementTFX43 min
Mar 29, 8:40 AM MDTSpecial Weather StatementTFX50 min
Mar 29, 9:26 AM MDTSpecial Weather StatementTFX49 min
Mar 29, 7:17 PM MDTSpecial Weather StatementTFX58 min
Mar 29, 9:02 PM MDTSpecial Weather StatementTFX58 min
Mar 30, 2:14 PM MDTFire Weather WatchTFX37 hr
Mar 31, 2:39 PM MDTRed Flag WarningTFX30 hr
May 20, 6:29 PM MDTSpecial Weather StatementTFX31 min
Jun 3, 4:58 PM MDTMesoscale DiscussionSPC3 hr
Jun 24, 1:11 PM MDTMesoscale DiscussionSPC2 hr
Jul 9, 2:16 PM MDTSpecial Weather StatementTFX29 min
Jul 9, 2:44 PM MDTSpecial Weather StatementTFX31 min
Jul 9, 3:17 PM MDTSpecial Weather StatementTFX28 min
Jul 9, 3:48 PM MDTSpecial Weather StatementTFX27 min
Jul 9, 4:14 PM MDTSpecial Weather StatementTFX31 min
Jul 11, 12:33 AM MDTRed Flag WarningTFX20 hr
Jul 11, 4:36 PM MDTSpecial Weather StatementTFX24 min
Jul 11, 5:05 PM MDTSpecial Weather StatementTFX25 min
Jul 18, 1:58 PM MDTRed Flag WarningTFX31 hr
Jul 20, 2:04 PM MDTFire Weather WatchTFX23 hr
Jul 20, 6:48 PM MDTSevere Thunderstorm WarningTFX27 min
Jul 21, 1:26 PM MDTRed Flag WarningTFX56 hr
Jul 21, 2:40 PM MDTMesoscale DiscussionSPC95 min
Jul 21, 2:48 PM MDTSpecial Weather StatementTFX27 min
Jul 21, 3:23 PM MDTSpecial Weather StatementTFX37 min
Jul 21, 3:49 PM MDTSpecial Weather StatementTFX26 min
Jul 21, 3:50 PM MDTSevere Thunderstorm WarningTFX40 min
Jul 21, 4:07 PM MDTSevere Thunderstorm WarningTFX38 min
Jul 21, 4:45 PM MDTSevere Thunderstorm WarningTFX45 min
Jul 21, 7:59 PM MDTSpecial Weather StatementTFX31 min
Jul 27, 6:14 PM MDTSpecial Weather StatementTFX31 min
Jul 27, 9:02 PM MDTSpecial Weather StatementTFX28 min
Jul 31, 3:12 AM MDTFire Weather WatchTFX10 hr
Jul 31, 1:36 PM MDTRed Flag WarningTFX31 hr
Aug 4, 4:23 PM MDTSpecial Weather StatementTFX37 min
Aug 4, 4:57 PM MDTSpecial Weather StatementTFX33 min
Aug 4, 7:55 PM MDTSpecial Weather StatementTFX50 min
Aug 9, 3:47 AM MDTAreal Flood AdvisoryTFX3 hr
Aug 14, 3:39 AM MDTFire Weather WatchTFX11 hr
Aug 14, 2:40 PM MDTRed Flag WarningTFX54 hr
Sep 4, 2:36 PM MDTRed Flag WarningTFX30 hr
Sep 5, 2:10 AM MDTFire Weather WatchTFX18 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 12, 6:34 PM MDTSpecial Weather StatementTFX56 min
Sep 16, 2:18 PM MDTRed Flag WarningTFX55 hr
Oct 4, 9:14 AM MDTRed Flag WarningTFX35 hr
Oct 15, 1:23 PM MDTFire Weather WatchTFX25 hr
Oct 16, 2:37 PM MDTRed Flag WarningTFX27 hr
Nov 14, 3:04 PM MSTFire Weather WatchTFX11 hr
Nov 15, 2:20 AM MSTRed Flag WarningTFX17 hr
Nov 21, 2:41 AM MSTFire Weather WatchTFX8 hr
Nov 21, 10:35 AM MSTRed Flag WarningTFX30 hr
Dec 1, 3:42 AM MSTRed Flag WarningTFX17 hr
Dec 1, 10:24 PM MSTRed Flag WarningTFX16 hr
Dec 26, 2:02 PM MSTSpecial Weather StatementTFX43 min
Dec 26, 2:59 PM MSTSpecial Weather StatementTFX46 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.