Alert archive / Wyoming / Big Horn County
Weather alerts in Big Horn County, Wyoming, 2021
61 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Big Horn County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 61
- Warnings
- 19
- Watches
- 17
- Advisories
- 8
- Busiest month
- July16 alerts
- Busiest day
- July 12, 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.
Big Horn County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 1 | 0% | |||
| 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 Cheyenne, WY: tornado warnings | 5 | 1 | 80% | 9 | 11% | 29 min |
| NWS Cheyenne, WY: severe thunderstorm warnings | 144 | 82 | 43% | 200 | 78% | 20 min |
| NWS Cheyenne, WY: flash flood warnings | 13 | 9 | 31% | 19 | 84% | 35 min |
| NWS Billings, MT: severe thunderstorm warnings | 51 | 23 | 55% | 84 | 42% | 18 min |
| NWS Billings, MT: flash flood warnings | 2 | 0 | 100% | 0 | ||
| NWS Salt Lake City, UT: tornado warnings | 0 | 5 | 0% | |||
| NWS Salt Lake City, UT: severe thunderstorm warnings | 116 | 26 | 78% | 152 | 42% | 22 min |
| NWS Salt Lake City, UT: flash flood warnings | 137 | 54 | 61% | 125 | 58% | 85 min |
| NWS Riverton, WY: tornado warnings | 1 | 0 | 100% | 0 | ||
| NWS Riverton, WY: severe thunderstorm warnings | 21 | 2 | 90% | 19 | 16% | 22 min |
| NWS Riverton, WY: flash flood warnings | 6 | 2 | 67% | 5 | 80% | 54 min |
| NWS Rapid City, SD: tornado warnings | 5 | 3 | 40% | 7 | 86% | 22 min |
| NWS Rapid City, SD: severe thunderstorm warnings | 212 | 171 | 19% | 380 | 79% | 26 min |
| NWS Rapid City, SD: 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 12, 2:21 AM MST | High Wind Watch | RIW | 24 hr |
| Jan 13, 2:50 AM MST | High Wind Warning | RIW | 38 hr |
| Feb 4, 2:10 AM MST | Winter Weather Advisory | RIW | 45 hr |
| Feb 6, 2:29 AM MST | Winter Weather Advisory | RIW | 39 hr |
| Feb 11, 2:35 AM MST | Wind Chill Advisory | RIW | 18 hr |
| Mar 8, 3:50 AM MST | Winter Storm Watch | RIW | 23 hr |
| Mar 9, 3:09 AM MST | Winter Weather Advisory | RIW | 38 hr |
| Mar 13, 11:23 AM MST | Winter Weather Advisory | RIW | 33 hr |
| Mar 27, 3:11 AM MDT | High Wind Watch | RIW | 33 hr |
| Mar 28, 1:44 AM MDT | High Wind Warning | RIW | 40 hr |
| Apr 9, 5:10 PM MDT | High Wind Watch | RIW | 18 hr |
| Apr 10, 11:16 AM MDT | High Wind Warning | RIW | 15 hr |
| Apr 13, 3:37 PM MDT | Winter Storm Watch | RIW | 13 hr |
| Apr 13, 3:37 PM MDT | Winter Weather Advisory | RIW | 68 hr |
| Apr 17, 2:30 AM MDT | Winter Storm Watch | RIW | 25 hr |
| Apr 18, 3:15 AM MDT | Winter Storm Warning | RIW | 42 hr |
| Apr 25, 3:04 AM MDT | Winter Weather Advisory | RIW | 57 hr |
| May 19, 6:20 PM MDT | Special Weather Statement | RIW | 25 min |
| Jun 4, 8:24 AM MDT | Flood Watch | RIW | 3 days |
| Jun 4, 2:32 PM MDT | Special Weather Statement | RIW | 28 min |
| Jun 4, 2:47 PM MDT | Special Weather Statement | RIW | 28 min |
| Jun 6, 6:44 AM MDT | Areal Flood Warning | RIW | 45 hr |
| Jun 8, 4:28 PM MDT | Special Weather Statement | RIW | 32 min |
| Jul 4, 4:22 PM MDT | Special Weather Statement | RIW | 23 min |
| Jul 4, 4:25 PM MDT | Special Weather Statement | RIW | 35 min |
| Jul 7, 1:40 PM MDT | Special Weather Statement | RIW | 35 min |
| Jul 7, 8:52 PM MDT | Special Weather Statement | RIW | 38 min |
| Jul 11, 8:01 PM MDT | Special Weather Statement | RIW | 29 min |
| Jul 11, 8:32 PM MDT | Special Weather Statement | RIW | 28 min |
| Jul 12, 3:35 AM MDT | Fire Weather Watch | RIW | 11 hr |
| Jul 12, 2:06 PM MDT | Red Flag Warning | RIW | 33 hr |
| Jul 13, 2:21 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jul 13, 6:53 PM MDT | Special Weather Statement | RIW | 37 min |
| Jul 13, 7:28 PM MDT | Special Weather Statement | RIW | 32 min |
| Jul 16, 3:25 PM MDT | Special Weather Statement | RIW | 50 min |
| Jul 16, 3:54 PM MDT | Special Weather Statement | RIW | 36 min |
| Jul 19, 1:28 PM MDT | Red Flag Warning | RIW | 32 hr |
| Jul 30, 4:56 PM MDT | Special Weather Statement | RIW | 34 min |
| Jul 31, 1:41 PM MDT | Areal Flood Advisory | RIW | 3 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 9, 2:58 AM MDT | Fire Weather Watch | BYZ | 10 hr |
| Aug 16, 1:24 PM MDT | Red Flag Warning | BYZ | 35 hr |
| 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 16, 1:59 PM MDT | Red Flag Warning | RIW | 54 hr |
| Sep 27, 1:50 AM MDT | Fire Weather Watch | BYZ | 12 hr |
| Sep 27, 2:05 AM MDT | Fire Weather Watch | RIW | 12 hr |
| Sep 27, 1:37 PM MDT | Red Flag Warning | RIW | 28 hr |
| Sep 27, 2:06 PM MDT | Red Flag Warning | BYZ | 31 hr |
| Oct 9, 3:42 PM MDT | Winter Storm Watch | RIW | 24 hr |
| Oct 10, 4:03 PM MDT | Winter Storm Watch | RIW | 14 hr |
| Oct 10, 4:03 PM MDT | Winter Storm Warning | RIW | 68 hr |
| Oct 17, 2:32 PM MDT | Winter Storm Watch | RIW | 24 hr |
| Oct 18, 3:53 AM MDT | Winter Storm Warning | RIW | 43 hr |
| Nov 15, 3:58 AM MST | High Wind Warning | RIW | 40 hr |
| Dec 3, 9:11 AM MST | High Wind Warning | RIW | 54 hr |
| Dec 3, 10:26 AM MST | High Wind Watch | RIW | 22 hr |
| Dec 26, 10:28 AM MST | Special Weather Statement | RIW | 62 min |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Mesoscale Discussion | 1 |
| Special Weather Statement | 16 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flood Watch | 1 |
| Areal Flood Advisory | 1 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 6 |
| Winter Weather Advisory | 6 |
| Cold | |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 5 |
| High Wind Watch | 4 |
| Fire | |
| Red Flag Warning | 10 |
| Fire Weather Watch | 6 |
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.