Alert archive / Iowa / Shelby County
Weather alerts in Shelby County, Iowa, 2023
97 weather alerts in 2023, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Shelby County and its neighbors
Each county as a circle sized by its count in 2023. Tap one for its archive.
- Alerts
- 97
- Warnings
- 35
- Watches
- 16
- Advisories
- 24
- Busiest month
- April17 alerts
- Busiest day
- July 12, 20235 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 1 tornado reports fell inside a warning.
Shelby County, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 1 | 0% | |||
| Severe thunderstorm warnings | 22 | 5 | 77% | 2 | 100% | 35 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Omaha, NE: tornado warnings | 47 | 22 | 53% | 74 | 78% | 26 min |
| NWS Omaha, NE: severe thunderstorm warnings | 371 | 147 | 60% | 513 | 81% | 23 min |
| NWS Omaha, NE: flash flood warnings | 16 | 7 | 56% | 17 | 59% | 57 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, 2:37 PM CST | Winter Weather Advisory | OAX | 51 hr |
| Jan 16, 2:29 AM CST | Winter Storm Watch | OAX | 36 hr |
| Jan 17, 7:35 AM CST | Winter Storm Warning | OAX | 46 hr |
| Jan 18, 12:53 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Jan 22, 12:55 AM CST | Dense Fog Advisory | OAX | 11 hr |
| Jan 22, 9:03 PM CST | Dense Fog Advisory | OAX | 13 hr |
| Jan 28, 3:20 AM CST | Wind Chill Advisory | OAX | 31 hr |
| Feb 15, 3:24 AM CST | Winter Weather Advisory | OAX | 37 hr |
| Feb 16, 2:00 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 16, 8:02 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 21, 3:30 AM CST | Winter Weather Advisory | OAX | 58 hr |
| Mar 8, 3:53 AM CST | Winter Weather Advisory | OAX | 38 hr |
| Mar 11, 4:06 AM CST | Winter Weather Advisory | OAX | 11 hr |
| Mar 16, 3:20 AM CDT | Wind Advisory | OAX | 19 hr |
| Mar 25, 3:12 PM CDT | Winter Weather Advisory | OAX | 19 hr |
| Mar 31, 3:55 AM CDT | Wind Advisory | OAX | 27 hr |
| Apr 7, 2:31 PM CDT | Red Flag Warning | OAX | 29 hr |
| Apr 11, 3:03 PM CDT | Red Flag Warning | OAX | 29 hr |
| Apr 12, 2:25 AM CDT | Fire Weather Watch | OAX | 12 hr |
| Apr 12, 2:26 PM CDT | Red Flag Warning | OAX | 30 hr |
| Apr 14, 8:32 PM CDT | Severe Thunderstorm Warning | OAX | 58 min |
| Apr 15, 2:40 PM CDT | Wind Advisory | OAX | 28 hr |
| Apr 19, 2:45 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 19, 3:45 PM CDT | Tornado Watch | SPC | 7 hr |
| Apr 19, 6:11 PM CDT | Severe Thunderstorm Warning | OAX | 14 min |
| Apr 19, 7:11 PM CDT | Severe Thunderstorm Warning | OAX | 49 min |
| Apr 19, 7:40 PM CDT | Severe Thunderstorm Warning | OAX | 32 min |
| Apr 19, 8:21 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 21, 3:23 AM CDT | Freeze Watch | OAX | 24 hr |
| Apr 21, 3:23 AM CDT | Freeze Warning | OAX | 30 hr |
| Apr 22, 2:56 AM CDT | Freeze Warning | OAX | 30 hr |
| Apr 23, 11:46 AM CDT | Freeze Warning | OAX | 21 hr |
| Apr 30, 2:46 AM CDT | Wind Advisory | OAX | 17 hr |
| May 6, 10:52 PM CDT | Dense Fog Advisory | OAX | 9 hr |
| May 7, 4:51 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 7, 2:10 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 7, 6:45 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 7, 9:17 PM CDT | Severe Thunderstorm Warning | OAX | 28 min |
| May 7, 10:38 PM CDT | Severe Thunderstorm Warning | OAX | 48 min |
| May 7, 11:04 PM CDT | Severe Thunderstorm Warning | OAX | 30 min |
| May 8, 9:01 PM CDT | Severe Thunderstorm Warning | OAX | 29 min |
| May 12, 1:09 PM CDT | Tornado Watch | SPC | 8 hr |
| May 30, 2:12 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 2:11 PM CDT | Areal Flood Advisory | OAX | 3 hr |
| Jun 17, 2:24 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 17, 3:13 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 17, 4:48 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jun 24, 3:10 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jun 24, 6:38 AM CDT | Special Weather Statement | OAX | 37 min |
| Jun 24, 5:04 PM CDT | Severe Thunderstorm Warning | OAX | 26 min |
| Jul 4, 3:29 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 12, 12:10 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 12, 4:41 AM CDT | Mesoscale Discussion | SPC | 94 min |
| Jul 12, 5:50 AM CDT | Severe Thunderstorm Warning | OAX | 40 min |
| Jul 12, 6:05 AM CDT | Severe Thunderstorm Warning | OAX | 55 min |
| Jul 12, 6:15 AM CDT | Severe Thunderstorm Warning | OAX | 14 min |
| Jul 17, 1:40 AM CDT | Severe Thunderstorm Warning | OAX | 50 min |
| Jul 17, 5:15 AM CDT | Severe Thunderstorm Warning | OAX | 32 min |
| Jul 17, 7:14 AM CDT | Severe Thunderstorm Warning | OAX | 18 min |
| Jul 24, 2:08 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 24, 3:03 AM CDT | Heat Advisory | OAX | 5 days |
| Jul 24, 5:18 AM CDT | Severe Thunderstorm Warning | OAX | 27 min |
| Jul 27, 3:50 AM CDT | Excessive Heat Warning | OAX | 41 hr |
| Jul 28, 3:55 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 28, 4:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 28, 6:32 PM CDT | Severe Thunderstorm Warning | OAX | 28 min |
| Jul 28, 6:53 PM CDT | Severe Thunderstorm Warning | OAX | 35 min |
| Aug 2, 2:26 AM CDT | Severe Thunderstorm Warning | OAX | 37 min |
| Aug 2, 2:38 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 2, 2:47 AM CDT | Flash Flood Warning | OAX | 8 hr |
| Aug 2, 4:45 AM CDT | Flash Flood Warning | OAX | 6 hr |
| Aug 2, 10:20 AM CDT | Areal Flood Warning | OAX | 3 hr |
| Aug 4, 3:29 AM CDT | Dense Fog Advisory | OAX | 6 hr |
| Aug 5, 3:01 PM CDT | Tornado Watch | SPC | 7 hr |
| Aug 5, 5:02 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Aug 5, 7:53 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 5, 9:31 PM CDT | Severe Thunderstorm Warning | OAX | 29 min |
| Aug 5, 10:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Aug 17, 1:28 PM CDT | Excessive Heat Watch | OAX | 26 hr |
| Aug 18, 3:16 PM CDT | Excessive Heat Warning | OAX | 7 days |
| Aug 21, 2:55 PM CDT | Excessive Heat Watch | OAX | 12 hr |
| Sep 19, 12:09 PM CDT | Severe Thunderstorm Warning | OAX | 32 min |
| Sep 19, 2:21 PM CDT | Special Weather Statement | OAX | 24 min |
| Sep 19, 2:26 PM CDT | Severe Thunderstorm Warning | OAX | 49 min |
| Sep 19, 2:49 PM CDT | Areal Flood Advisory | OAX | 2 hr |
| Sep 23, 9:37 AM CDT | Mesoscale Discussion | SPC | 113 min |
| Sep 23, 4:58 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 27, 6:05 AM CDT | Dense Fog Advisory | OAX | 5 hr |
| Oct 3, 5:03 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Oct 6, 2:05 AM CDT | Frost Advisory | OAX | 31 hr |
| Oct 9, 3:01 PM CDT | Frost Advisory | OAX | 18 hr |
| Oct 11, 8:50 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 15, 2:05 PM CDT | Frost Advisory | OAX | 19 hr |
| Oct 27, 2:57 AM CDT | Freeze Warning | OAX | 31 hr |
| Dec 21, 6:11 PM CST | Dense Fog Advisory | OAX | 17 hr |
| Dec 22, 8:50 PM CST | Dense Fog Advisory | OAX | 15 hr |
| Dec 25, 7:00 AM CST | Mesoscale Discussion | SPC | 6 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 | 22 |
| Severe Thunderstorm Watch | 8 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 20 |
| Special Weather Statement | 2 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flash Flood Warning | 2 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 6 |
| Heat | |
| Excessive Heat Warning | 2 |
| Excessive Heat Watch | 2 |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 4 |
| Freeze Watch | 1 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 4 |
| Fire | |
| Red Flag Warning | 3 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 7 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20222024
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.