Alert archive / Iowa / Decatur County
Weather alerts in Decatur County, Iowa, 2011
121 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Decatur County and its neighbors
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Alerts
- 121
- Warnings
- 33
- Watches
- 23
- Advisories
- 26
- Busiest month
- June43 alerts
- Busiest day
- June 20, 201113 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 5 tornado warnings covering Decatur County in 2011 had a tornado report inside them.
Decatur County, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 5 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 15 | 8 | 47% | 7 | 71% | 9 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Des Moines, IA: tornado warnings | 58 | 19 | 67% | 53 | 75% | 27 min |
| NWS Des Moines, IA: severe thunderstorm warnings | 313 | 174 | 44% | 468 | 74% | 22 min |
| NWS Des Moines, IA: flash flood warnings | 34 | 13 | 62% | 30 | 87% | 136 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 8, 3:13 PM CST | Winter Storm Watch | DMX | 24 hr |
| Jan 9, 3:20 PM CST | Winter Weather Advisory | DMX | 51 hr |
| Jan 11, 5:56 PM CST | Wind Chill Advisory | DMX | 15 hr |
| Jan 17, 2:50 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 22, 4:05 AM CST | Winter Weather Advisory | DMX | 29 hr |
| Jan 28, 9:29 AM CST | Dense Fog Advisory | DMX | 3 hr |
| Jan 30, 4:01 AM CST | Winter Storm Watch | DMX | 36 hr |
| Jan 30, 4:01 AM CST | Winter Weather Advisory | DMX | 68 hr |
| Jan 31, 4:20 PM CST | Blizzard Warning | DMX | 42 hr |
| Feb 1, 10:36 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 1, 3:36 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 2, 3:48 AM CST | Winter Weather Advisory | DMX | 8 hr |
| Feb 2, 3:09 PM CST | Wind Chill Advisory | DMX | 18 hr |
| Feb 7, 3:35 AM CST | Wind Chill Advisory | DMX | 32 hr |
| Feb 8, 3:44 PM CST | Wind Chill Advisory | DMX | 20 hr |
| Feb 16, 12:59 AM CST | Dense Fog Advisory | DMX | 9 hr |
| Feb 16, 6:00 PM CST | Dense Fog Advisory | DMX | 16 hr |
| Feb 24, 3:47 AM CST | Winter Weather Advisory | DMX | 20 hr |
| Feb 24, 11:13 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 24, 12:05 PM CST | Winter Storm Warning | DMX | 12 hr |
| Feb 27, 3:42 PM CST | Winter Weather Advisory | DMX | 7 hr |
| Feb 27, 5:50 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Mar 20, 2:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Mar 22, 2:03 PM CDT | Tornado Watch | SPC | 7 hr |
| Mar 22, 6:45 PM CDT | Tornado Warning | DMX | 30 min |
| Mar 22, 7:09 PM CDT | Tornado Warning | DMX | 36 min |
| Mar 22, 7:48 PM CDT | Severe Thunderstorm Warning | DMX | 42 min |
| Mar 22, 8:29 PM CDT | Severe Thunderstorm Warning | DMX | 31 min |
| Mar 22, 8:41 PM CDT | Tornado Warning | DMX | 34 min |
| Mar 22, 8:58 PM CDT | Severe Thunderstorm Warning | DMX | 17 min |
| Apr 3, 3:47 PM CDT | Wind Advisory | DMX | 26 hr |
| Apr 3, 4:49 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Apr 10, 3:54 AM CDT | Wind Advisory | DMX | 15 hr |
| Apr 19, 5:52 AM CDT | Mesoscale Discussion | SPC | 83 min |
| May 2, 3:48 PM CDT | Frost Advisory | DMX | 15 hr |
| May 3, 4:05 PM CDT | Frost Advisory | DMX | 15 hr |
| May 11, 8:09 AM CDT | Mesoscale Discussion | SPC | 66 min |
| May 11, 2:53 PM CDT | Tornado Watch | SPC | 6 hr |
| May 11, 5:44 PM CDT | Severe Thunderstorm Warning | DMX | 46 min |
| May 11, 6:17 PM CDT | Mesoscale Discussion | SPC | 28 min |
| May 11, 6:42 PM CDT | Severe Thunderstorm Warning | DMX | 48 min |
| May 12, 8:23 AM CDT | River Flood Warning | DMX | 13 hr |
| May 21, 2:25 PM CDT | Severe Thunderstorm Watch | SPC | 10 hr |
| May 21, 5:25 PM CDT | Mesoscale Discussion | SPC | 65 min |
| May 21, 6:07 PM CDT | Mesoscale Discussion | SPC | 53 min |
| May 21, 8:55 PM CDT | Mesoscale Discussion | SPC | 65 min |
| May 21, 8:59 PM CDT | Severe Thunderstorm Warning | DMX | 31 min |
| May 22, 10:53 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 24, 9:45 PM CDT | Flash Flood Watch | DMX | 24 hr |
| May 25, 1:05 AM CDT | River Flood Warning | DMX | 57 hr |
| May 25, 4:22 AM CDT | Wind Advisory | DMX | 17 hr |
| May 25, 3:53 PM CDT | Flash Flood Warning | DMX | 3 hr |
| May 29, 1:41 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 5, 2:52 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 8, 3:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 8, 5:18 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 9, 1:44 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 9, 9:50 AM CDT | Mesoscale Discussion | SPC | 55 min |
| Jun 9, 3:05 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 9, 3:44 PM CDT | Flash Flood Watch | DMX | 12 hr |
| Jun 9, 7:43 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jun 9, 9:48 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 9, 11:45 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jun 10, 1:39 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 13, 3:32 PM CDT | Flash Flood Watch | DMX | 36 hr |
| Jun 13, 9:23 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jun 13, 11:57 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jun 14, 2:56 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 14, 3:53 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 14, 7:47 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 14, 10:30 PM CDT | Severe Thunderstorm Warning | DMX | 60 min |
| Jun 18, 7:29 AM CDT | Severe Thunderstorm Warning | DMX | 31 min |
| Jun 19, 6:51 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 19, 9:16 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 19, 11:14 PM CDT | Flash Flood Watch | DMX | 11 hr |
| Jun 19, 11:31 PM CDT | Severe Thunderstorm Warning | DMX | 44 min |
| Jun 19, 11:52 PM CDT | Tornado Warning | DMX | 23 min |
| Jun 19, 11:57 PM CDT | Tornado Warning | DMX | 22 min |
| Jun 20, 12:12 AM CDT | Severe Thunderstorm Warning | DMX | 48 min |
| Jun 20, 12:17 AM CDT | Severe Thunderstorm Warning | DMX | 43 min |
| Jun 20, 12:29 AM CDT | Flash Flood Warning | DMX | 6 hr |
| Jun 20, 12:41 AM CDT | Severe Thunderstorm Warning | DMX | 49 min |
| Jun 20, 1:40 AM CDT | Mesoscale Discussion | SPC | 35 min |
| Jun 20, 3:27 AM CDT | Mesoscale Discussion | SPC | 33 min |
| Jun 20, 3:14 PM CDT | Flash Flood Watch | DMX | 12 hr |
| Jun 20, 6:53 PM CDT | Tornado Watch | SPC | 6 hr |
| Jun 20, 10:22 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 25, 11:30 AM CDT | River Flood Warning | DMX | 21 hr |
| Jun 26, 3:42 PM CDT | Flash Flood Watch | DMX | 14 hr |
| Jun 26, 4:56 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 26, 8:48 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jun 26, 9:03 PM CDT | River Flood Warning | DMX | 47 hr |
| Jun 26, 9:56 PM CDT | Severe Thunderstorm Warning | DMX | 64 min |
| Jun 26, 10:44 PM CDT | Severe Thunderstorm Warning | DMX | 46 min |
| Jun 29, 3:44 AM CDT | Excessive Heat Watch | DMX | 12 hr |
| Jun 29, 3:38 PM CDT | Heat Advisory | DMX | 51 hr |
| Jul 5, 6:10 PM CDT | Tornado Watch | SPC | 4 hr |
| Jul 5, 7:49 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jul 10, 2:06 PM CDT | Heat Advisory | DMX | 29 hr |
| Jul 14, 3:37 PM CDT | Excessive Heat Watch | DMX | 24 hr |
| Jul 15, 3:32 PM CDT | Excessive Heat Warning | DMX | 6 days |
| Jul 21, 7:09 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jul 22, 3:40 AM CDT | Excessive Heat Warning | DMX | 41 hr |
| Jul 23, 4:57 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jul 23, 5:16 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jul 26, 11:30 AM CDT | Heat Advisory | DMX | 35 hr |
| Jul 28, 10:56 AM CDT | Heat Advisory | DMX | 11 hr |
| Jul 28, 5:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 30, 3:47 PM CDT | Heat Advisory | DMX | 72 hr |
| Aug 2, 3:53 AM CDT | Excessive Heat Warning | DMX | 15 hr |
| Aug 6, 5:32 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 6, 8:10 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 6, 10:45 PM CDT | Severe Thunderstorm Warning | DMX | 45 min |
| Aug 6, 11:06 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Aug 22, 1:42 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 23, 12:45 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 11, 3:06 AM CDT | Dense Fog Advisory | DMX | 7 hr |
| Oct 11, 10:11 AM CDT | Dense Fog Advisory | DMX | 65 min |
| Oct 18, 9:30 PM CDT | Freeze Warning | DMX | 11 hr |
| Oct 20, 3:42 AM CDT | Freeze Warning | DMX | 29 hr |
| Nov 8, 3:42 AM CST | Winter Weather Advisory | DMX | 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 | 15 |
| Tornado Warning | 5 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 7 |
| Mesoscale Discussion | 39 |
| Flooding | |
| Flash Flood Warning | 2 |
| River Flood Warning | 4 |
| Flash Flood Watch | 6 |
| Winter | |
| Blizzard Warning | 1 |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 7 |
| Heat | |
| Excessive Heat Warning | 3 |
| Excessive Heat Watch | 2 |
| Heat Advisory | 5 |
| Cold | |
| Freeze Warning | 2 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 4 |
| Wind and dust | |
| Wind Advisory | 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 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.