Alert archive / Wyoming / Niobrara County
Weather alerts in Niobrara County, Wyoming, 2011
106 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Niobrara County and its neighbors
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Alerts
- 106
- Warnings
- 35
- Watches
- 20
- Advisories
- 17
- Busiest month
- July27 alerts
- Busiest day
- July 2, 20118 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
1 of 4 tornado warnings covering Niobrara County in 2011 had a tornado report inside them; 3 of 3 tornado reports fell inside a warning, on average 17 minutes after it went out.
Niobrara County, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 1 | 75% | 3 | 100% | 17 min |
| Severe thunderstorm warnings | 20 | 7 | 65% | 6 | 50% | 11 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Cheyenne, WY: tornado warnings | 34 | 11 | 68% | 18 | 83% | 12 min |
| NWS Cheyenne, WY: severe thunderstorm warnings | 197 | 99 | 50% | 282 | 73% | 20 min |
| NWS Cheyenne, WY: flash flood warnings | 25 | 18 | 28% | 50 | 90% | 81 min |
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 |
|---|---|---|---|
| Dec 31, 8:57 PM MST | Wind Chill Warning | CYS | 13 hr |
| Jan 1, 3:50 AM MST | Wind Chill Advisory | CYS | 7 hr |
| Jan 8, 2:59 PM MST | Winter Weather Advisory | CYS | 32 hr |
| Jan 9, 6:34 PM MST | Wind Chill Advisory | CYS | 9 hr |
| Jan 10, 3:02 PM MST | Wind Chill Advisory | CYS | 18 hr |
| Jan 18, 3:52 PM MST | Winter Weather Advisory | CYS | 23 hr |
| Jan 30, 2:38 PM MST | Wind Chill Watch | CYS | 14 hr |
| Jan 30, 2:38 PM MST | Winter Weather Advisory | CYS | 23 hr |
| Jan 31, 4:08 AM MST | Wind Chill Warning | CYS | 54 hr |
| Feb 7, 4:45 AM MST | Winter Weather Advisory | CYS | 33 hr |
| Feb 8, 2:57 PM MST | Wind Chill Warning | CYS | 19 hr |
| Feb 11, 10:03 AM MST | High Wind Warning | CYS | 56 hr |
| Feb 12, 4:39 AM MST | High Wind Watch | CYS | 6 hr |
| Feb 16, 1:01 AM MST | High Wind Warning | CYS | 40 hr |
| Feb 19, 4:08 AM MST | Winter Storm Watch | CYS | 10 hr |
| Feb 19, 2:31 PM MST | Winter Storm Warning | CYS | 16 hr |
| Feb 19, 2:31 PM MST | Winter Weather Advisory | CYS | 26 hr |
| Feb 24, 3:28 AM MST | Winter Weather Advisory | CYS | 51 hr |
| Mar 3, 2:14 PM MST | Winter Weather Advisory | CYS | 21 hr |
| Mar 5, 3:47 PM MST | Winter Storm Watch | CYS | 11 hr |
| Mar 6, 2:32 AM MST | Winter Weather Advisory | CYS | 27 hr |
| Mar 30, 5:00 AM MDT | High Wind Watch | CYS | 22 hr |
| Apr 20, 2:37 PM MDT | High Wind Watch | CYS | 19 hr |
| Apr 21, 9:40 AM MDT | High Wind Warning | CYS | 34 hr |
| May 9, 1:17 PM MDT | Mesoscale Discussion | SPC | 58 min |
| May 9, 2:26 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 9, 4:57 PM MDT | Severe Thunderstorm Warning | CYS | 48 min |
| May 9, 4:57 PM MDT | Mesoscale Discussion | SPC | 93 min |
| May 9, 4:59 PM MDT | Severe Thunderstorm Warning | CYS | 46 min |
| May 9, 5:43 PM MDT | Severe Thunderstorm Warning | CYS | 43 min |
| May 9, 6:03 PM MDT | Severe Thunderstorm Warning | CYS | 57 min |
| May 9, 8:16 PM MDT | Mesoscale Discussion | SPC | 29 min |
| May 17, 3:26 PM MDT | Flood Watch | CYS | 64 hr |
| May 29, 4:38 AM MDT | High Wind Watch | CYS | 23 hr |
| May 29, 4:48 PM MDT | Dense Fog Advisory | CYS | 16 hr |
| Jun 6, 3:50 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 8, 9:37 PM MDT | Severe Thunderstorm Warning | CYS | 38 min |
| Jun 9, 1:43 PM MDT | Severe Thunderstorm Warning | CYS | 23 min |
| Jun 9, 7:09 PM MDT | Mesoscale Discussion | SPC | 96 min |
| Jun 11, 1:40 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 11, 3:35 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 11, 6:07 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Jun 11, 7:11 PM MDT | Mesoscale Discussion | SPC | 64 min |
| Jun 12, 12:52 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Jun 12, 2:56 PM MDT | Tornado Warning | CYS | 34 min |
| Jun 12, 3:07 PM MDT | Tornado Warning | CYS | 27 min |
| Jun 24, 1:25 PM MDT | Mesoscale Discussion | SPC | 65 min |
| Jun 24, 1:52 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 24, 3:46 PM MDT | Severe Thunderstorm Warning | CYS | 59 min |
| Jun 24, 4:12 PM MDT | Severe Thunderstorm Warning | CYS | 29 min |
| Jun 25, 1:24 PM MDT | Mesoscale Discussion | SPC | 96 min |
| Jun 30, 11:57 AM MDT | Mesoscale Discussion | SPC | 63 min |
| Jun 30, 12:18 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 30, 2:03 PM MDT | Severe Thunderstorm Warning | CYS | 24 min |
| Jul 2, 12:17 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 2, 2:13 PM MDT | Tornado Watch | SPC | 8 hr |
| Jul 2, 3:50 PM MDT | Tornado Warning | CYS | 40 min |
| Jul 2, 4:29 PM MDT | Severe Thunderstorm Warning | CYS | 46 min |
| Jul 2, 4:42 PM MDT | Severe Thunderstorm Warning | CYS | 48 min |
| Jul 2, 4:59 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 2, 5:30 PM MDT | Severe Thunderstorm Warning | CYS | 45 min |
| Jul 2, 5:40 PM MDT | Severe Thunderstorm Warning | CYS | 37 min |
| Jul 2, 6:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Jul 4, 5:27 PM MDT | Severe Thunderstorm Warning | CYS | 33 min |
| Jul 5, 1:17 PM MDT | Mesoscale Discussion | SPC | 73 min |
| Jul 6, 3:19 PM MDT | Areal Flood Advisory | CYS | 75 min |
| Jul 6, 3:44 PM MDT | Flash Flood Warning | CYS | 3 hr |
| Jul 11, 1:50 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jul 11, 2:07 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 11, 2:38 PM MDT | Severe Thunderstorm Warning | CYS | 41 min |
| Jul 11, 3:16 PM MDT | Severe Thunderstorm Warning | CYS | 29 min |
| Jul 11, 3:44 PM MDT | Tornado Warning | CYS | 46 min |
| Jul 11, 4:01 PM MDT | Mesoscale Discussion | SPC | 29 min |
| Jul 11, 4:06 PM MDT | Tornado Watch | SPC | 5 hr |
| Jul 11, 4:24 PM MDT | Severe Thunderstorm Warning | CYS | 51 min |
| Jul 24, 2:06 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jul 25, 11:23 AM MDT | Mesoscale Discussion | SPC | 97 min |
| Jul 25, 1:32 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jul 29, 12:59 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Jul 29, 1:54 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 29, 4:46 PM MDT | Mesoscale Discussion | SPC | 59 min |
| Aug 3, 1:01 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Aug 5, 4:25 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 5:08 PM MDT | Special Weather Statement | CYS | 52 min |
| Aug 8, 8:24 PM MDT | Severe Thunderstorm Warning | CYS | 53 min |
| Aug 9, 9:25 AM MDT | Mesoscale Discussion | SPC | 95 min |
| Aug 9, 4:33 PM MDT | Severe Thunderstorm Warning | CYS | 41 min |
| Aug 9, 5:02 PM MDT | Mesoscale Discussion | SPC | 118 min |
| Aug 19, 5:17 PM MDT | Special Weather Statement | CYS | 58 min |
| Aug 19, 6:54 PM MDT | Special Weather Statement | CYS | 51 min |
| Aug 25, 3:59 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Aug 26, 5:39 PM MDT | Special Weather Statement | CYS | 66 min |
| Aug 29, 1:05 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Aug 29, 2:12 PM MDT | Special Weather Statement | CYS | 63 min |
| Aug 29, 2:42 PM MDT | Severe Thunderstorm Warning | CYS | 63 min |
| Sep 20, 7:51 PM MDT | Frost Advisory | CYS | 12 hr |
| Oct 6, 2:19 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Oct 6, 2:32 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Oct 31, 3:07 AM MDT | Winter Storm Watch | CYS | 12 hr |
| Oct 31, 2:52 PM MDT | Winter Storm Warning | CYS | 42 hr |
| Nov 8, 4:10 AM MST | Dense Fog Advisory | CYS | 5 hr |
| Nov 18, 3:15 AM MST | Winter Storm Warning | CYS | 25 hr |
| Nov 30, 3:31 AM MST | Winter Weather Advisory | CYS | 31 hr |
| Dec 20, 2:42 PM MST | Winter Weather Advisory | CYS | 40 hr |
| Dec 29, 8:59 PM MST | High Wind Watch | CYS | 15 hr |
| Dec 30, 11:29 AM MST | High Wind Warning | CYS | 29 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 20 |
| Tornado Warning | 4 |
| Severe Thunderstorm Watch | 8 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 29 |
| Special Weather Statement | 5 |
| Flooding | |
| Flash Flood Warning | 1 |
| Flood Watch | 1 |
| Areal Flood Advisory | 1 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 3 |
| Winter Weather Advisory | 10 |
| Cold | |
| Wind Chill Warning | 3 |
| Wind Chill Watch | 1 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 4 |
| High Wind Watch | 5 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20102012
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.