Alert archive / Iowa / Cass County
Weather alerts in Cass County, Iowa, 2023
96 weather alerts in 2023, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Cass County and its neighbors
Each county as a circle sized by its count in 2023. Tap one for its archive.
- Alerts
- 96
- Warnings
- 29
- Watches
- 18
- Advisories
- 18
- Busiest month
- April23 alerts
- Busiest day
- July 17, 20236 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Cass County, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 16 | 7 | 56% | 2 | 50% | 2 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Des Moines, IA: tornado warnings | 37 | 13 | 65% | 26 | 73% | 15 min |
| NWS Des Moines, IA: severe thunderstorm warnings | 195 | 120 | 38% | 328 | 88% | 22 min |
| NWS Des Moines, IA: flash flood warnings | 5 | 3 | 40% | 4 | 75% | 103 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 3, 4:19 AM CST | Dense Fog Advisory | DMX | 8 hr |
| Jan 17, 3:07 AM CST | Winter Storm Watch | DMX | 12 hr |
| Jan 17, 3:09 PM CST | Winter Storm Warning | DMX | 45 hr |
| Jan 17, 3:09 PM CST | Winter Weather Advisory | DMX | 45 hr |
| Jan 18, 12:53 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Jan 22, 6:46 PM CST | Dense Fog Advisory | DMX | 14 hr |
| Jan 28, 2:06 PM CST | Wind Chill Advisory | DMX | 21 hr |
| Feb 15, 3:27 AM CST | Winter Storm Warning | DMX | 39 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, 2:47 AM CST | Winter Weather Advisory | DMX | 57 hr |
| Mar 8, 3:04 PM CST | Winter Weather Advisory | DMX | 33 hr |
| Mar 16, 3:12 AM CDT | Wind Advisory | DMX | 25 hr |
| Mar 25, 2:41 PM CDT | Winter Weather Advisory | DMX | 22 hr |
| Mar 30, 3:31 PM CDT | Fire Weather Watch | DMX | 13 hr |
| Mar 31, 3:30 AM CDT | Wind Advisory | DMX | 28 hr |
| Apr 4, 3:02 AM CDT | Red Flag Warning | DMX | 15 hr |
| Apr 4, 2:48 PM CDT | Tornado Watch | SPC | 7 hr |
| Apr 4, 6:43 PM CDT | Severe Thunderstorm Warning | DMX | 47 min |
| Apr 7, 3:03 PM CDT | Fire Weather Watch | DMX | 12 hr |
| Apr 8, 2:41 AM CDT | Red Flag Warning | DMX | 17 hr |
| Apr 12, 2:57 AM CDT | Fire Weather Watch | DMX | 11 hr |
| Apr 12, 2:57 AM CDT | Red Flag Warning | DMX | 17 hr |
| Apr 12, 2:20 PM CDT | Red Flag Warning | DMX | 30 hr |
| Apr 14, 9:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Apr 14, 9:08 PM CDT | Severe Thunderstorm Warning | DMX | 52 min |
| Apr 14, 9:48 PM CDT | Special Weather Statement | DMX | 42 min |
| Apr 14, 10:28 PM CDT | Special Weather Statement | DMX | 62 min |
| Apr 15, 2:47 PM CDT | Wind Advisory | DMX | 44 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, 7:24 PM CDT | Severe Thunderstorm Warning | DMX | 51 min |
| Apr 19, 8:21 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 21, 3:24 AM CDT | Freeze Watch | DMX | 24 hr |
| Apr 21, 3:24 AM CDT | Freeze Warning | DMX | 30 hr |
| Apr 22, 3:38 AM CDT | Freeze Warning | DMX | 29 hr |
| Apr 23, 4:08 AM CDT | Freeze Watch | DMX | 10 hr |
| Apr 23, 2:31 PM CDT | Freeze Warning | DMX | 18 hr |
| Apr 30, 2:41 AM CDT | Wind Advisory | DMX | 17 hr |
| May 6, 10:41 PM CDT | Dense Fog Advisory | DMX | 12 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, 4:10 PM CDT | Severe Thunderstorm Watch | SPC | 10 hr |
| May 7, 6:02 PM CDT | Mesoscale Discussion | SPC | 88 min |
| May 7, 7:36 PM CDT | Severe Thunderstorm Warning | DMX | 39 min |
| May 7, 7:58 PM CDT | Severe Thunderstorm Warning | DMX | 47 min |
| May 30, 2:12 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 1, 6:07 PM CDT | Special Weather Statement | DMX | 23 min |
| 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, 1:27 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 24, 5:21 PM CDT | Severe Thunderstorm Warning | DMX | 39 min |
| Jun 24, 5:44 PM CDT | Severe Thunderstorm Warning | DMX | 46 min |
| Jun 29, 5:49 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 29, 8:16 AM CDT | Severe Thunderstorm Warning | DMX | 44 min |
| Jun 29, 8:54 AM CDT | Severe Thunderstorm Warning | DMX | 51 min |
| Jun 30, 6:14 AM CDT | Severe Thunderstorm Warning | DMX | 61 min |
| Jul 4, 6:55 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 12, 4:41 AM CDT | Mesoscale Discussion | SPC | 94 min |
| Jul 12, 5:15 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 12, 6:07 AM CDT | Severe Thunderstorm Warning | DMX | 38 min |
| Jul 12, 6:41 AM CDT | Severe Thunderstorm Warning | DMX | 64 min |
| Jul 12, 7:25 AM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 17, 1:09 AM CDT | Severe Thunderstorm Warning | DMX | 51 min |
| Jul 17, 2:07 AM CDT | Special Weather Statement | DMX | 23 min |
| Jul 17, 5:21 AM CDT | Severe Thunderstorm Warning | DMX | 39 min |
| Jul 17, 5:32 AM CDT | Severe Thunderstorm Warning | DMX | 28 min |
| Jul 17, 8:24 AM CDT | Severe Thunderstorm Warning | DMX | 51 min |
| Jul 17, 8:40 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 24, 5:07 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 24, 5:38 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 25, 2:47 PM CDT | Heat Advisory | DMX | 3 days |
| Jul 27, 3:19 AM CDT | Excessive Heat Warning | DMX | 42 hr |
| Jul 28, 4:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 29, 6:09 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 2, 1:59 AM CDT | Special Weather Statement | OAX | 16 min |
| Aug 2, 2:03 AM CDT | Special Weather Statement | DMX | 42 min |
| Aug 2, 2:38 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 2, 5:43 AM CDT | Flash Flood Warning | DMX | 4 hr |
| Aug 5, 5:02 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Aug 5, 10:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Aug 6, 12:35 AM CDT | Special Weather Statement | DMX | 55 min |
| Aug 17, 3:07 PM CDT | Excessive Heat Watch | DMX | 71 hr |
| Aug 18, 2:18 PM CDT | Excessive Heat Warning | DMX | 7 days |
| Aug 21, 2:56 PM CDT | Excessive Heat Watch | DMX | 24 hr |
| Sep 16, 2:28 AM CDT | Dense Fog Advisory | DMX | 7 hr |
| Sep 19, 3:40 PM CDT | Special Weather Statement | DMX | 35 min |
| Sep 23, 1:34 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Sep 23, 4:58 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 6, 2:31 AM CDT | Frost Advisory | DMX | 30 hr |
| Oct 9, 2:23 PM CDT | Frost Advisory | DMX | 19 hr |
| Oct 13, 2:14 AM CDT | Special Weather Statement | DMX | 31 min |
| Oct 15, 2:51 PM CDT | Frost Advisory | DMX | 18 hr |
| Oct 27, 3:05 AM CDT | Freeze Warning | DMX | 31 hr |
| Dec 22, 3:20 PM CST | Dense Fog Advisory | DMX | 20 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 | 16 |
| Severe Thunderstorm Watch | 8 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 22 |
| Special Weather Statement | 9 |
| Flooding | |
| Flash Flood Warning | 1 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 4 |
| Heat | |
| Excessive Heat Warning | 2 |
| Excessive Heat Watch | 2 |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 4 |
| Freeze Watch | 2 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 4 |
| Fire | |
| Red Flag Warning | 4 |
| Fire Weather Watch | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
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.