Alert archive / Nebraska / Lancaster County
Weather alerts in Lancaster County, Nebraska, 2021
151 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Lancaster County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 151
- Warnings
- 44
- Watches
- 22
- Advisories
- 51
- Busiest month
- June24 alerts
- Busiest day
- June 24, 202112 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 1 tornado warnings covering Lancaster County in 2021 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 0 minutes after it went out.
Lancaster County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 1 | 0% | 1 | 100% | 0 min |
| Severe thunderstorm warnings | 21 | 14 | 33% | 15 | 73% | 39 min |
| Flash flood warnings | 3 | 2 | 33% | 2 | 100% | 58 min |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Omaha, NE: tornado warnings | 30 | 11 | 63% | 47 | 68% | 11 min |
| NWS Omaha, NE: severe thunderstorm warnings | 202 | 120 | 41% | 399 | 86% | 32 min |
| NWS Omaha, NE: flash flood warnings | 13 | 11 | 15% | 54 | 89% | 71 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, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 1, 12:49 AM CST | Freezing Fog Advisory | OAX | 7 hr |
| Jan 2, 8:28 AM CST | Dense Fog Advisory | OAX | 5 hr |
| Jan 2, 3:40 PM CST | Dense Fog Advisory | OAX | 19 hr |
| Jan 3, 2:38 PM CST | Dense Fog Advisory | OAX | 21 hr |
| Jan 13, 3:30 PM CST | High Wind Warning | OAX | 51 hr |
| Jan 13, 3:30 PM CST | Wind Advisory | OAX | 33 hr |
| Jan 14, 3:49 AM CST | High Wind Warning | OAX | 38 hr |
| Jan 14, 3:51 AM CST | Blizzard Warning | OAX | 35 hr |
| Jan 15, 2:10 PM CST | Winter Weather Advisory | OAX | 5 hr |
| Jan 22, 3:11 PM CST | Winter Weather Advisory | OAX | 36 hr |
| Jan 23, 12:55 PM CST | Winter Storm Watch | OAX | 14 hr |
| Jan 24, 3:15 AM CST | Winter Storm Warning | OAX | 49 hr |
| Jan 25, 4:10 AM CST | Winter Weather Advisory | OAX | 29 hr |
| Jan 25, 4:58 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 25, 10:41 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 25, 3:26 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 31, 9:34 PM CST | Dense Fog Advisory | OAX | 38 hr |
| Feb 2, 2:34 PM CST | Dense Fog Advisory | OAX | 19 hr |
| Feb 3, 3:12 AM CST | Winter Weather Advisory | OAX | 33 hr |
| Feb 5, 3:26 AM CST | Winter Weather Advisory | OAX | 36 hr |
| Feb 6, 3:14 PM CST | Winter Weather Advisory | OAX | 37 hr |
| Feb 8, 5:35 AM CST | Wind Chill Advisory | OAX | 4 hr |
| Feb 8, 3:32 PM CST | Wind Chill Advisory | OAX | 18 hr |
| Feb 11, 2:16 PM CST | Wind Chill Advisory | OAX | 22 hr |
| Feb 11, 2:16 PM CST | Winter Weather Advisory | OAX | 40 hr |
| Feb 12, 3:25 AM CST | Wind Chill Advisory | OAX | 33 hr |
| Feb 12, 2:13 PM CST | Wind Chill Watch | OAX | 37 hr |
| Feb 13, 3:28 AM CST | Wind Chill Advisory | OAX | 39 hr |
| Feb 13, 3:28 AM CST | Winter Weather Advisory | OAX | 39 hr |
| Feb 14, 3:13 AM CST | Wind Chill Warning | OAX | 56 hr |
| Feb 19, 10:01 PM CST | Dense Fog Advisory | OAX | 14 hr |
| Feb 20, 3:09 PM CST | Winter Weather Advisory | OAX | 24 hr |
| Mar 9, 2:33 PM CST | Wind Advisory | OAX | 27 hr |
| Mar 13, 3:25 PM CST | Wind Advisory | OAX | 27 hr |
| Mar 14, 12:29 PM CDT | Areal Flood Advisory | OAX | 10 hr |
| Mar 16, 12:52 AM CDT | Dense Fog Advisory | OAX | 8 hr |
| Mar 21, 3:15 AM CDT | Wind Advisory | OAX | 14 hr |
| Mar 28, 3:17 AM CDT | Fire Weather Watch | OAX | 11 hr |
| Mar 28, 2:06 PM CDT | Red Flag Warning | OAX | 31 hr |
| Mar 30, 3:38 AM CDT | Red Flag Warning | OAX | 16 hr |
| Mar 31, 11:57 AM CDT | Red Flag Warning | OAX | 8 hr |
| Apr 1, 3:53 PM CDT | Fire Weather Watch | OAX | 12 hr |
| Apr 2, 3:29 AM CDT | Red Flag Warning | OAX | 17 hr |
| Apr 6, 7:21 AM CDT | Severe Thunderstorm Warning | OAX | 24 min |
| Apr 6, 7:43 AM CDT | Special Weather Statement | OAX | 32 min |
| Apr 6, 7:50 AM CDT | Special Weather Statement | OAX | 25 min |
| Apr 13, 2:38 PM CDT | Freeze Warning | OAX | 17 hr |
| Apr 14, 2:25 PM CDT | Freeze Warning | OAX | 18 hr |
| Apr 19, 3:55 AM CDT | Freeze Watch | OAX | 11 hr |
| Apr 19, 2:29 PM CDT | Freeze Warning | OAX | 19 hr |
| Apr 19, 2:29 PM CDT | Freeze Warning | OAX | 43 hr |
| Apr 21, 3:36 AM CDT | Freeze Warning | OAX | 29 hr |
| May 1, 10:01 AM CDT | Red Flag Warning | OAX | 10 hr |
| May 2, 10:41 PM CDT | Special Weather Statement | OAX | 34 min |
| May 2, 11:05 PM CDT | Special Weather Statement | OAX | 10 min |
| May 2, 11:18 PM CDT | Special Weather Statement | OAX | 42 min |
| May 2, 11:43 PM CDT | Special Weather Statement | OAX | 47 min |
| May 5, 3:47 PM CDT | Mesoscale Discussion | SPC | 88 min |
| May 5, 5:39 PM CDT | Severe Thunderstorm Warning | OAX | 51 min |
| May 8, 6:42 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 26, 6:07 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 26, 6:24 PM CDT | Flash Flood Watch | OAX | 14 hr |
| Jun 10, 10:05 AM CDT | Heat Advisory | OAX | 10 hr |
| Jun 11, 5:36 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 11, 7:28 AM CDT | Mesoscale Discussion | SPC | 92 min |
| Jun 11, 9:00 AM CDT | Severe Thunderstorm Warning | OAX | 30 min |
| Jun 11, 10:43 AM CDT | Areal Flood Advisory | OAX | 3 hr |
| Jun 16, 3:06 PM CDT | Heat Advisory | OAX | 29 hr |
| Jun 18, 9:27 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 19, 11:09 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jun 19, 11:59 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jun 23, 10:12 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jun 23, 10:37 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 24, 1:36 AM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 24, 1:55 AM CDT | Severe Thunderstorm Warning | OAX | 50 min |
| Jun 24, 2:24 AM CDT | Severe Thunderstorm Warning | OAX | 51 min |
| Jun 24, 2:51 AM CDT | Severe Thunderstorm Warning | OAX | 39 min |
| Jun 24, 2:54 AM CDT | Severe Thunderstorm Warning | OAX | 36 min |
| Jun 24, 2:23 PM CDT | Flash Flood Watch | OAX | 37 hr |
| Jun 24, 5:10 PM CDT | Severe Thunderstorm Warning | OAX | 40 min |
| Jun 24, 5:34 PM CDT | Flash Flood Warning | OAX | 4 hr |
| Jun 24, 5:55 PM CDT | Severe Thunderstorm Warning | OAX | 50 min |
| Jun 24, 6:12 PM CDT | Severe Thunderstorm Warning | OAX | 48 min |
| Jun 24, 9:27 PM CDT | Areal Flood Warning | OAX | 13 hr |
| Jun 25, 1:21 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 25, 9:29 PM CDT | Special Weather Statement | OAX | 46 min |
| Jul 9, 9:12 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 9, 9:58 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 9, 10:20 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 9, 11:26 PM CDT | Severe Thunderstorm Warning | OAX | 64 min |
| Jul 9, 11:55 PM CDT | Severe Thunderstorm Warning | OAX | 65 min |
| Jul 10, 1:20 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 10, 2:18 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 23, 3:06 AM CDT | Heat Advisory | OAX | 41 hr |
| Jul 26, 3:18 AM CDT | Heat Advisory | OAX | 4 days |
| Jul 29, 2:58 PM CDT | Heat Advisory | OAX | 30 hr |
| Jul 30, 7:54 PM CDT | Special Weather Statement | OAX | 36 min |
| Jul 30, 8:16 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jul 30, 8:17 PM CDT | Special Weather Statement | OAX | 28 min |
| Jul 30, 8:47 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 31, 2:35 AM CDT | Special Weather Statement | OAX | 55 min |
| Aug 7, 6:11 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 6:35 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 7, 8:33 PM CDT | Areal Flood Advisory | OAX | 4 hr |
| Aug 7, 8:41 PM CDT | Severe Thunderstorm Warning | OAX | 49 min |
| Aug 7, 9:37 PM CDT | Severe Thunderstorm Warning | OAX | 22 min |
| Aug 7, 9:54 PM CDT | Severe Thunderstorm Warning | OAX | 17 min |
| Aug 7, 10:25 PM CDT | Flash Flood Warning | OAX | 2 hr |
| Aug 8, 12:41 AM CDT | Areal Flood Warning | OAX | 12 hr |
| Aug 8, 2:37 PM CDT | Heat Advisory | OAX | 54 hr |
| Aug 10, 3:02 AM CDT | Heat Advisory | OAX | 42 hr |
| Aug 20, 1:51 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 20, 4:39 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 20, 7:06 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 23, 4:14 PM CDT | Heat Advisory | OAX | 28 hr |
| Aug 24, 3:46 PM CDT | Heat Advisory | OAX | 28 hr |
| Aug 25, 1:16 AM CDT | Severe Thunderstorm Warning | OAX | 44 min |
| Aug 25, 4:07 AM CDT | Heat Advisory | OAX | 40 hr |
| Aug 27, 5:45 PM CDT | Special Weather Statement | OAX | 45 min |
| Aug 31, 1:56 AM CDT | Severe Thunderstorm Warning | OAX | 34 min |
| Aug 31, 3:02 AM CDT | Mesoscale Discussion | SPC | 118 min |
| Aug 31, 5:35 AM CDT | Areal Flood Advisory | OAX | 77 min |
| Aug 31, 6:18 AM CDT | Special Weather Statement | OAX | 27 min |
| Aug 31, 6:28 AM CDT | Severe Thunderstorm Warning | OAX | 47 min |
| Aug 31, 6:43 AM CDT | Severe Thunderstorm Warning | OAX | 32 min |
| Sep 2, 3:54 PM CDT | Flash Flood Watch | OAX | 12 hr |
| Sep 3, 12:15 AM CDT | Areal Flood Advisory | OAX | 6 hr |
| Oct 13, 2:51 AM CDT | Special Weather Statement | OAX | 24 min |
| Oct 15, 3:13 AM CDT | Frost Advisory | OAX | 30 hr |
| Oct 21, 3:12 AM CDT | Frost Advisory | OAX | 31 hr |
| Oct 23, 9:14 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Oct 23, 9:53 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Oct 24, 1:18 PM CDT | Areal Flood Advisory | OAX | 3 hr |
| Oct 24, 1:47 PM CDT | Flash Flood Warning | OAX | 3 hr |
| Oct 28, 3:20 AM CDT | Wind Advisory | OAX | 16 hr |
| Nov 10, 2:36 PM CST | Wind Advisory | OAX | 51 hr |
| Dec 9, 11:48 AM CST | Winter Weather Advisory | OAX | 37 hr |
| Dec 13, 2:49 AM CST | High Wind Watch | OAX | 24 hr |
| Dec 14, 2:20 AM CST | High Wind Warning | OAX | 44 hr |
| Dec 14, 2:26 AM CST | Fire Weather Watch | OAX | 12 hr |
| Dec 14, 2:21 PM CST | Red Flag Warning | OAX | 28 hr |
| Dec 15, 12:28 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Dec 15, 1:23 PM CST | Tornado Watch | SPC | 7 hr |
| Dec 15, 2:26 PM CST | Severe Thunderstorm Warning | OAX | 64 min |
| Dec 15, 2:30 PM CST | Mesoscale Discussion | SPC | 90 min |
| Dec 15, 2:54 PM CST | Severe Thunderstorm Warning | OAX | 81 min |
| Dec 15, 3:23 PM CST | Tornado Warning | OAX | 16 min |
| Dec 15, 5:08 PM CST | Blowing Dust Advisory | OAX | 4 hr |
| Dec 15, 8:34 PM CST | Wind Advisory | OAX | 5 hr |
| Dec 24, 4:01 AM CST | Dense Fog Advisory | OAX | 7 hr |
| Dec 31, 3:30 AM CST | Dense Fog Advisory | OAX | 9 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.