Alert archive / Montana / Powder River County
Weather alerts in Powder River County, Montana, 2021
87 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Powder River County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 87
- Warnings
- 27
- Watches
- 20
- Advisories
- 13
- Busiest month
- July19 alerts
- Busiest day
- May 29, 20214 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Powder River County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 5 | 4 | 20% | 4 | 75% | 3 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Billings, MT: severe thunderstorm warnings | 51 | 23 | 55% | 84 | 42% | 18 min |
| NWS Billings, MT: flash flood warnings | 2 | 0 | 100% | 0 |
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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 7, 5:23 PM MST | Winter Weather Advisory | BYZ | 16 hr |
| Jan 9, 6:15 AM MST | Special Weather Statement | BYZ | 2 hr |
| Jan 9, 8:16 AM MST | Special Weather Statement | BYZ | 89 min |
| Jan 11, 3:04 AM MST | High Wind Watch | BYZ | 34 hr |
| Jan 12, 2:51 AM MST | High Wind Warning | BYZ | 65 hr |
| Jan 17, 2:47 AM MST | Winter Weather Advisory | BYZ | 33 hr |
| Jan 25, 9:12 AM MST | Special Weather Statement | BYZ | 2 hr |
| Feb 3, 2:50 PM MST | Winter Storm Watch | BYZ | 37 hr |
| Feb 4, 1:48 PM MST | Winter Weather Advisory | BYZ | 62 hr |
| Feb 6, 3:26 AM MST | Wind Chill Advisory | BYZ | 10 days |
| Feb 20, 3:00 AM MST | High Wind Warning | BYZ | 4 days |
| Mar 17, 6:23 AM MDT | Special Weather Statement | BYZ | 3 hr |
| Mar 27, 3:15 AM MDT | High Wind Watch | BYZ | 23 hr |
| Mar 28, 2:27 AM MDT | High Wind Warning | BYZ | 40 hr |
| Apr 17, 3:31 PM MDT | Winter Weather Advisory | BYZ | 42 hr |
| Apr 27, 4:31 AM MDT | Special Weather Statement | BYZ | 4 hr |
| May 20, 12:58 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 20, 3:52 PM MDT | Special Weather Statement | BYZ | 23 min |
| May 20, 4:24 PM MDT | Special Weather Statement | BYZ | 36 min |
| May 28, 3:55 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 28, 6:50 PM MDT | Special Weather Statement | BYZ | 40 min |
| May 28, 7:30 PM MDT | Special Weather Statement | BYZ | 45 min |
| May 28, 7:48 PM MDT | Severe Thunderstorm Warning | BYZ | 27 min |
| May 28, 8:26 PM MDT | Special Weather Statement | BYZ | 34 min |
| Jun 8, 6:15 PM MDT | Mesoscale Discussion | SPC | 90 min |
| Jun 9, 3:19 AM MDT | High Wind Watch | BYZ | 24 hr |
| Jun 9, 3:57 AM MDT | Fire Weather Watch | BYZ | 10 hr |
| Jun 9, 1:38 PM MDT | Red Flag Warning | BYZ | 32 hr |
| Jun 10, 2:53 AM MDT | High Wind Warning | BYZ | 23 hr |
| Jun 13, 2:34 PM MDT | Excessive Heat Warning | BYZ | 54 hr |
| Jun 14, 9:26 AM MDT | Red Flag Warning | BYZ | 43 hr |
| Jun 18, 2:46 AM MDT | Fire Weather Watch | BYZ | 11 hr |
| Jun 18, 2:00 PM MDT | Red Flag Warning | BYZ | 31 hr |
| Jun 24, 2:37 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jun 29, 1:38 AM MDT | Excessive Heat Watch | BYZ | 36 hr |
| Jun 29, 2:27 PM MDT | Fire Weather Watch | BYZ | 23 hr |
| Jun 30, 1:34 PM MDT | Heat Advisory | BYZ | 4 days |
| Jun 30, 1:40 PM MDT | Red Flag Warning | BYZ | 31 hr |
| Jul 4, 6:11 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 6, 2:37 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jul 6, 5:00 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 6, 8:21 PM MDT | Severe Thunderstorm Warning | BYZ | 54 min |
| Jul 6, 9:00 PM MDT | Severe Thunderstorm Warning | BYZ | 32 min |
| Jul 6, 10:27 PM MDT | Mesoscale Discussion | SPC | 93 min |
| Jul 7, 3:03 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 7, 9:13 PM MDT | Severe Thunderstorm Warning | BYZ | 62 min |
| Jul 7, 10:08 PM MDT | Special Weather Statement | BYZ | 52 min |
| Jul 7, 10:59 PM MDT | Special Weather Statement | BYZ | 61 min |
| Jul 13, 2:21 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jul 13, 4:25 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 13, 6:37 PM MDT | Severe Thunderstorm Warning | BYZ | 23 min |
| Jul 16, 11:06 AM MDT | Excessive Heat Warning | BYZ | 6 days |
| Jul 18, 2:06 AM MDT | Fire Weather Watch | BYZ | 13 hr |
| Jul 18, 3:10 PM MDT | Red Flag Warning | BYZ | 57 hr |
| Jul 22, 1:41 PM MDT | Special Weather Statement | BYZ | 49 min |
| Jul 24, 12:18 PM MDT | Excessive Heat Watch | BYZ | 25 hr |
| Jul 25, 1:39 PM MDT | Excessive Heat Warning | BYZ | 58 hr |
| Aug 7, 3:06 AM MDT | Fire Weather Watch | BYZ | 11 hr |
| Aug 7, 2:26 PM MDT | Red Flag Warning | BYZ | 34 hr |
| Aug 8, 9:11 PM MDT | Special Weather Statement | BYZ | 79 min |
| Aug 9, 2:58 AM MDT | Fire Weather Watch | BYZ | 10 hr |
| Aug 9, 12:55 PM MDT | Red Flag Warning | BYZ | 57 hr |
| Aug 14, 3:08 AM MDT | Fire Weather Watch | BYZ | 11 hr |
| Aug 14, 2:07 PM MDT | Red Flag Warning | BYZ | 3 days |
| Aug 15, 1:30 PM MDT | Heat Advisory | BYZ | 55 hr |
| Aug 16, 7:06 PM MDT | Special Weather Statement | BYZ | 39 min |
| Aug 16, 7:51 PM MDT | Special Weather Statement | BYZ | 39 min |
| Aug 25, 9:46 PM MDT | Special Weather Statement | BYZ | 44 min |
| Sep 4, 2:20 PM MDT | Fire Weather Watch | BYZ | 24 hr |
| Sep 5, 2:29 PM MDT | Red Flag Warning | BYZ | 30 hr |
| Sep 14, 1:04 PM MDT | Red Flag Warning | BYZ | 31 hr |
| Sep 16, 1:53 PM MDT | Red Flag Warning | BYZ | 55 hr |
| Sep 27, 1:50 AM MDT | Fire Weather Watch | BYZ | 12 hr |
| Sep 27, 2:06 PM MDT | Red Flag Warning | BYZ | 31 hr |
| Oct 9, 1:08 PM MDT | Winter Storm Watch | BYZ | 38 hr |
| Oct 10, 2:47 PM MDT | Winter Storm Warning | BYZ | 3 days |
| Oct 11, 3:34 AM MDT | Winter Weather Advisory | BYZ | 47 hr |
| Oct 13, 3:58 AM MDT | Mesoscale Discussion | SPC | 6 hr |
| Nov 12, 1:58 PM MST | High Wind Watch | BYZ | 12 hr |
| Nov 12, 1:58 PM MST | High Wind Warning | BYZ | 28 hr |
| Nov 15, 2:44 AM MST | High Wind Warning | BYZ | 39 hr |
| Nov 24, 3:56 AM MST | Special Weather Statement | BYZ | 4 hr |
| Dec 13, 2:37 PM MST | Winter Weather Advisory | BYZ | 50 hr |
| Dec 26, 4:06 AM MST | Winter Weather Advisory | BYZ | 17 hr |
| Dec 26, 6:39 PM MST | Wind Chill Advisory | BYZ | 41 hr |
| Dec 28, 2:27 PM MST | Wind Chill Advisory | BYZ | 23 hr |
| Dec 30, 12:30 PM MST | Wind Chill Advisory | BYZ | 22 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 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.