Alert archive / Montana / Powell County

Weather alerts in Powell County, Montana, 2017

165 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Powell County and its neighbors

Each county as a circle sized by its count in 2017. Tap one for its archive.

Alerts
165
Warnings
47
Watches
19
Advisories
61
Busiest month
July27 alerts
Busiest day
June 8, 20178 alerts

Over time

By month

Warning verification

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

Powell County, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings5180%333%8 min
Flash flood warnings00

Each office's whole area, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Missoula, MT: tornado warnings010%
NWS Missoula, MT: severe thunderstorm warnings13838%2438%20 min
NWS Missoula, MT: flash flood warnings010%

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 1, 4:57 AM MSTWinter Storm WarningMSO14 hr
Jan 2, 3:41 AM MSTWind Chill WarningMSO31 hr
Jan 7, 2:35 PM MSTWinter Storm WatchMSO59 days
Jan 7, 2:35 PM MSTWinter Weather AdvisoryMSO50 hr
Jan 7, 11:27 PM MSTWinter Storm WarningMSO42 hr
Jan 8, 3:35 AM MSTWinter Weather AdvisoryMSO37 hr
Jan 10, 1:31 PM MSTWind Chill AdvisoryMSO21 hr
Jan 10, 1:31 PM MSTWinter Weather AdvisoryMSO21 hr
Jan 17, 1:42 PM MSTWinter Weather AdvisoryMSO45 hr
Jan 18, 9:09 PM MSTFreezing Rain AdvisoryMSO14 hr
Jan 19, 11:24 PM MSTDense Fog AdvisoryMSO12 hr
Jan 20, 9:45 PM MSTFreezing Fog AdvisoryMSO11 hr
Jan 21, 1:59 PM MSTWinter Weather AdvisoryMSO43 hr
Jan 29, 2:29 PM MSTWinter Storm WatchMSO39 days
Jan 30, 12:07 PM MSTWinter Storm WarningMSO40 hr
Jan 31, 6:04 AM MSTWinter Weather AdvisoryMSO29 hr
Feb 1, 2:36 PM MSTWinter Weather AdvisoryMSO23 hr
Feb 2, 1:54 PM MSTWinter Weather AdvisoryMSO69 hr
Feb 3, 1:27 PM MSTWinter Storm WatchMSO14 hr
Feb 4, 3:09 AM MSTWinter Storm WarningMSO59 hr
Feb 6, 11:09 AM MSTWinter Weather AdvisoryMSO21 hr
Feb 6, 4:42 PM MSTSpecial Weather StatementMSO93 min
Feb 7, 9:24 AM MSTWinter Weather AdvisoryMSO24 hr
Feb 8, 11:42 AM MSTWinter Weather AdvisoryMSO23 hr
Feb 10, 10:18 PM MSTWinter Weather AdvisoryMSO12 hr
Feb 23, 5:10 AM MSTWinter Weather AdvisoryMSO4 hr
Feb 25, 1:58 PM MSTWinter Weather AdvisoryMSO46 hr
Feb 27, 2:39 PM MSTWinter Weather AdvisoryMSO23 hr
Feb 28, 2:14 PM MSTWind AdvisoryMSO30 hr
Feb 28, 2:17 PM MSTWinter Weather AdvisoryMSO46 hr
Mar 4, 1:37 PM MSTWinter Storm WarningMSO31 hr
Mar 4, 1:37 PM MSTWinter Weather AdvisoryMSO30 hr
Mar 5, 8:57 PM MSTWinter Weather AdvisoryMSO4 hr
Mar 6, 2:54 PM MSTWinter Weather AdvisoryMSO19 hr
Mar 7, 12:36 AM MSTSpecial Weather StatementMSO84 min
Mar 7, 2:42 PM MSTWinter Storm WarningMSO20 hr
Mar 7, 2:42 PM MSTWinter Weather AdvisoryMSO20 hr
Mar 8, 2:04 PM MSTWinter Weather AdvisoryMSO23 hr
Mar 9, 7:54 AM MSTWinter Storm WarningMSO5 hr
Mar 9, 3:06 PM MSTWinter Weather AdvisoryMSO23 hr
Mar 29, 2:26 PM MDTWinter Weather AdvisoryMSO41 hr
Apr 7, 9:35 PM MDTWinter Weather AdvisoryMSO38 hr
Apr 13, 2:43 PM MDTWinter Weather AdvisoryMSO33 hr
May 6, 3:16 PM MDTSevere Thunderstorm WarningMSO29 min
May 6, 3:41 PM MDTSevere Thunderstorm WarningMSO34 min
May 6, 3:42 PM MDTMesoscale DiscussionSPC63 min
May 12, 1:35 PM MDTMesoscale DiscussionSPC2 hr
May 12, 2:45 PM MDTSpecial Weather StatementMSO45 min
May 15, 12:54 PM MDTWinter Storm WatchMSO24 hr
May 16, 1:14 PM MDTWinter Storm WarningMSO38 hr
May 16, 6:49 PM MDTSpecial Weather StatementMSO26 min
May 23, 9:54 AM MDTHigh Wind WatchMSO17 hr
May 23, 9:54 AM MDTWind AdvisoryMSO35 hr
May 31, 4:49 PM MDTSpecial Weather StatementMSO41 min
Jun 1, 12:42 PM MDTMesoscale DiscussionSPC3 hr
Jun 1, 3:08 PM MDTSpecial Weather StatementMSO52 min
Jun 1, 3:59 PM MDTSpecial Weather StatementMSO46 min
Jun 4, 3:28 PM MDTMesoscale DiscussionSPC3 hr
Jun 4, 4:24 PM MDTSpecial Weather StatementMSO36 min
Jun 4, 4:25 PM MDTSpecial Weather StatementMSO35 min
Jun 4, 4:49 PM MDTSpecial Weather StatementMSO26 min
Jun 4, 5:11 PM MDTSpecial Weather StatementMSO49 min
Jun 8, 4:24 PM MDTSpecial Weather StatementMSO51 min
Jun 8, 4:24 PM MDTMesoscale DiscussionSPC96 min
Jun 8, 4:28 PM MDTSpecial Weather StatementMSO17 min
Jun 8, 4:37 PM MDTSevere Thunderstorm WarningMSO23 min
Jun 8, 4:46 PM MDTSevere Thunderstorm WatchSPC6 hr
Jun 8, 4:57 PM MDTSevere Thunderstorm WarningMSO33 min
Jun 8, 5:15 PM MDTSpecial Weather StatementMSO45 min
Jun 8, 5:18 PM MDTSpecial Weather StatementTFX27 min
Jun 10, 2:03 PM MDTFlood WatchMSO3 days
Jun 12, 7:36 PM MDTAreal Flood AdvisoryMSO24 hr
Jun 13, 10:45 AM MDTAreal Flood AdvisoryMSO9 hr
Jun 13, 7:54 PM MDTFlood WatchMSO10 hr
Jun 26, 8:19 PM MDTSpecial Weather StatementMSO41 min
Jun 26, 9:17 PM MDTSpecial Weather StatementMSO28 min
Jul 4, 9:41 PM MDTRed Flag WarningTFX23 hr
Jul 5, 8:47 PM MDTSpecial Weather StatementMSO28 min
Jul 9, 5:49 PM MDTSpecial Weather StatementMSO26 min
Jul 9, 6:14 PM MDTSpecial Weather StatementMSO46 min
Jul 9, 6:46 PM MDTSpecial Weather StatementMSO44 min
Jul 10, 4:16 PM MDTSevere Thunderstorm WarningMSO29 min
Jul 10, 5:38 PM MDTSpecial Weather StatementMSO37 min
Jul 10, 6:58 PM MDTSpecial Weather StatementMSO47 min
Jul 10, 7:25 PM MDTSpecial Weather StatementMSO20 min
Jul 10, 7:44 PM MDTSpecial Weather StatementMSO16 min
Jul 13, 6:13 PM MDTSpecial Weather StatementMSO32 min
Jul 13, 6:47 PM MDTSpecial Weather StatementMSO28 min
Jul 13, 6:48 PM MDTSpecial Weather StatementMSO27 min
Jul 14, 2:46 PM MDTRed Flag WarningTFX54 hr
Jul 15, 2:00 PM MDTRed Flag WarningMSO31 hr
Jul 15, 2:07 PM MDTMesoscale DiscussionSPC53 min
Jul 15, 5:53 PM MDTSpecial Weather StatementMSO52 min
Jul 18, 10:53 PM MDTSpecial Weather StatementMSO37 min
Jul 18, 11:29 PM MDTSpecial Weather StatementMSO16 min
Jul 19, 2:14 PM MDTRed Flag WarningMSO31 hr
Jul 20, 3:05 AM MDTRed Flag WarningTFX42 hr
Jul 22, 2:56 PM MDTRed Flag WarningTFX30 hr
Jul 23, 4:36 AM MDTFire Weather WatchTFX22 hr
Jul 23, 2:39 PM MDTRed Flag WarningTFX30 hr
Jul 24, 3:08 AM MDTRed Flag WarningMSO18 hr
Jul 28, 10:36 AM MDTFire Weather WatchTFX40 hr
Jul 31, 2:40 PM MDTRed Flag WarningMSO37 hr
Jul 31, 9:59 PM MDTRed Flag WarningTFX29 hr
Aug 11, 1:03 PM MDTRed Flag WarningMSO56 hr
Aug 12, 2:47 PM MDTFire Weather WatchTFX13 hr
Aug 13, 3:22 AM MDTRed Flag WarningTFX18 hr
Aug 17, 3:09 AM MDTRed Flag WarningTFX51 hr
Aug 17, 11:56 AM MDTRed Flag WarningMSO57 hr
Aug 18, 2:03 PM MDTRed Flag WarningMSO31 hr
Aug 19, 3:28 AM MDTRed Flag WarningTFX18 hr
Aug 24, 8:59 AM MDTRed Flag WarningMSO14 hr
Aug 29, 12:49 PM MDTRed Flag WarningMSO56 hr
Aug 29, 2:41 PM MDTRed Flag WarningTFX3 days
Aug 30, 4:41 PM MDTSpecial Weather StatementMSO34 min
Sep 1, 2:34 PM MDTFire Weather WatchMSO23 hr
Sep 1, 2:49 PM MDTFire Weather WatchTFX24 hr
Sep 2, 3:52 AM MDTRed Flag WarningTFX65 hr
Sep 2, 1:45 PM MDTRed Flag WarningMSO45 hr
Sep 7, 1:48 PM MDTFire Weather WatchMSO22 hr
Sep 7, 2:09 PM MDTFire Weather WatchTFX24 hr
Sep 8, 11:57 AM MDTRed Flag WarningMSO33 hr
Sep 8, 2:03 PM MDTRed Flag WarningTFX40 hr
Sep 11, 2:53 AM MDTRed Flag WarningMSO21 hr
Sep 11, 2:24 PM MDTRed Flag WarningMSO32 hr
Sep 11, 3:26 PM MDTRed Flag WarningTFX31 hr
Sep 12, 2:02 PM MDTRed Flag WarningMSO29 hr
Sep 12, 2:03 PM MDTWinter Storm WatchMSO43 hr
Sep 14, 9:29 AM MDTWinter Storm WarningMSO45 hr
Sep 19, 10:55 PM MDTWinter Weather AdvisoryMSO13 hr
Sep 21, 3:33 AM MDTWinter Weather AdvisoryMSO44 hr
Oct 1, 2:25 PM MDTWinter Storm WarningMSO40 hr
Oct 1, 2:25 PM MDTWinter Weather AdvisoryMSO43 hr
Oct 6, 11:31 AM MDTWind AdvisoryMSO30 hr
Oct 12, 1:11 PM MDTWinter Weather AdvisoryMSO30 hr
Oct 16, 2:37 PM MDTWind AdvisoryMSO33 hr
Oct 21, 2:30 PM MDTWind AdvisoryMSO30 hr
Oct 24, 1:08 PM MDTWind AdvisoryMSO29 hr
Oct 26, 4:22 AM MDTWinter Weather AdvisoryMSO4 hr
Oct 31, 2:38 PM MDTWinter Weather AdvisoryMSO4 days
Nov 1, 9:14 PM MDTWinter Weather AdvisoryMSO11 hr
Nov 3, 8:38 AM MDTWinter Storm WarningMSO24 hr
Nov 4, 2:35 PM MDTWinter Weather AdvisoryMSO45 hr
Nov 10, 3:04 AM MSTDense Fog AdvisoryMSO8 hr
Nov 13, 3:30 AM MSTWinter Weather AdvisoryMSO30 hr
Nov 13, 5:04 AM MSTDense Fog AdvisoryMSO5 hr
Nov 15, 7:24 PM MSTWinter Weather AdvisoryMSO19 hr
Nov 21, 4:45 AM MSTDense Fog AdvisoryMSO6 hr
Nov 21, 1:14 PM MSTHigh Wind WatchMSO38 hr
Nov 23, 3:27 AM MSTWind AdvisoryMSO25 hr
Nov 28, 10:48 AM MSTWinter Weather AdvisoryMSO21 hr
Dec 2, 3:26 AM MSTWinter Weather AdvisoryMSO44 hr
Dec 13, 6:15 AM MSTWinter Weather AdvisoryMSO14 hr
Dec 14, 2:27 PM MSTWinter Weather AdvisoryMSO45 hr
Dec 16, 2:45 PM MSTWinter Weather AdvisoryMSO44 hr
Dec 17, 2:58 PM MSTWinter Storm WatchMSO24 hr
Dec 17, 2:58 PM MSTWinter Storm WarningMSO68 hr
Dec 19, 4:45 AM MSTWinter Weather AdvisoryMSO39 hr
Dec 21, 4:03 AM MSTWinter Weather AdvisoryMSO53 hr
Dec 22, 3:50 PM MSTWinter Storm WarningMSO7 hr
Dec 24, 3:31 AM MSTWinter Weather AdvisoryMSO43 hr
Dec 27, 4:40 AM MSTWinter Storm WatchMSO23 hr
Dec 27, 3:02 PM MSTWinter Storm WarningMSO3 days
Dec 27, 3:02 PM MSTWinter Weather AdvisoryMSO20 hr
Dec 30, 12:47 PM MSTWinter Weather AdvisoryMSO10 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 archive20162018

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.