Alert archive / Iowa / Decatur County
Weather alerts in Decatur County, Iowa, 2016
88 weather alerts in 2016, 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 2016. Tap one for its archive.
- Alerts
- 88
- Warnings
- 8
- Watches
- 22
- Advisories
- 29
- Busiest month
- July20 alerts
- Busiest day
- July 19, 20168 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Decatur County, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 4 | 2 | 50% | 0 | ||
| Flash flood warnings | 1 | 1 | 0% | 0 |
Each office's whole area, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Des Moines, IA: tornado warnings | 19 | 11 | 42% | 23 | 65% | 16 min |
| NWS Des Moines, IA: severe thunderstorm warnings | 162 | 79 | 51% | 246 | 65% | 21 min |
| NWS Des Moines, IA: flash flood warnings | 39 | 28 | 28% | 64 | 84% | 135 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 7, 6:46 AM CST | Dense Fog Advisory | DMX | 5 hr |
| Jan 8, 4:45 AM CST | Dense Fog Advisory | DMX | 14 hr |
| Jan 8, 9:45 PM CST | Winter Weather Advisory | DMX | 6 hr |
| Jan 9, 3:55 AM CST | Wind Chill Advisory | DMX | 32 hr |
| Jan 16, 3:46 PM CST | Wind Chill Advisory | DMX | 41 hr |
| Jan 17, 12:06 PM CST | Wind Chill Advisory | DMX | 21 hr |
| Jan 18, 3:43 PM CST | Winter Weather Advisory | DMX | 29 hr |
| Feb 2, 5:40 PM CST | Dense Fog Advisory | DMX | 9 hr |
| Feb 7, 11:18 PM CST | Winter Weather Advisory | DMX | 34 hr |
| Feb 18, 3:48 PM CST | Wind Advisory | DMX | 26 hr |
| Mar 13, 10:15 PM CDT | Dense Fog Advisory | DMX | 14 hr |
| Mar 15, 3:05 PM CDT | Wind Advisory | DMX | 28 hr |
| Mar 23, 1:07 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 23, 3:03 PM CDT | Tornado Watch | SPC | 7 hr |
| Mar 23, 7:45 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 7, 3:21 PM CDT | Freeze Watch | DMX | 12 hr |
| Apr 8, 3:34 AM CDT | Freeze Warning | DMX | 29 hr |
| Apr 11, 9:42 AM CDT | Freeze Warning | DMX | 23 hr |
| Apr 26, 8:58 AM CDT | Wind Advisory | DMX | 3 hr |
| Apr 27, 1:58 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 27, 2:33 PM CDT | Tornado Watch | SPC | 7 hr |
| Apr 27, 5:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Apr 27, 6:17 PM CDT | Special Weather Statement | DMX | 28 min |
| May 11, 3:10 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| May 11, 5:34 AM CDT | Mesoscale Discussion | SPC | 101 min |
| May 13, 12:52 PM CDT | Mesoscale Discussion | SPC | 113 min |
| May 13, 1:25 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 18, 6:26 AM CDT | Dense Fog Advisory | DMX | 3 hr |
| May 25, 4:08 AM CDT | Special Weather Statement | DMX | 52 min |
| May 26, 12:17 AM CDT | Special Weather Statement | DMX | 58 min |
| May 26, 2:09 PM CDT | Tornado Watch | SPC | 8 hr |
| May 27, 5:41 PM CDT | Mesoscale Discussion | SPC | 64 min |
| May 27, 7:53 PM CDT | Flash Flood Watch | DMX | 8 hr |
| Jun 1, 3:42 AM CDT | Dense Fog Advisory | DMX | 3 hr |
| Jun 14, 7:00 PM CDT | Mesoscale Discussion | SPC | 60 min |
| Jun 20, 3:07 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 20, 4:10 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 20, 6:42 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Jun 20, 9:04 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 22, 3:28 AM CDT | Heat Advisory | DMX | 16 hr |
| Jun 25, 9:57 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 30, 1:29 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 2, 3:16 AM CDT | Flash Flood Watch | DMX | 18 hr |
| Jul 4, 3:36 PM CDT | Heat Advisory | DMX | 28 hr |
| Jul 7, 1:22 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 7, 1:37 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 7, 4:27 AM CDT | Mesoscale Discussion | SPC | 93 min |
| Jul 7, 5:26 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 13, 10:33 AM CDT | Mesoscale Discussion | SPC | 117 min |
| Jul 13, 11:14 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 17, 9:29 AM CDT | Severe Thunderstorm Warning | DMX | 46 min |
| Jul 17, 11:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 18, 1:39 AM CDT | Flash Flood Watch | DMX | 7 hr |
| Jul 18, 3:43 PM CDT | Excessive Heat Watch | DMX | 36 hr |
| Jul 19, 3:36 AM CDT | Flash Flood Watch | DMX | 24 hr |
| Jul 19, 12:28 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 19, 1:48 PM CDT | Severe Thunderstorm Warning | DMX | 42 min |
| Jul 19, 2:11 PM CDT | Severe Thunderstorm Warning | DMX | 49 min |
| Jul 19, 2:18 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 19, 2:59 PM CDT | Flash Flood Warning | DMX | 6 hr |
| Jul 19, 4:24 PM CDT | Excessive Heat Watch | DMX | 12 hr |
| Jul 19, 4:24 PM CDT | Excessive Heat Warning | DMX | 4 days |
| Aug 2, 3:44 AM CDT | Flash Flood Watch | DMX | 8 hr |
| Aug 3, 2:58 AM CDT | Dense Fog Advisory | DMX | 5 hr |
| Aug 4, 1:28 PM CDT | Heat Advisory | DMX | 6 hr |
| Aug 11, 3:46 AM CDT | Flash Flood Watch | DMX | 27 hr |
| Aug 11, 3:58 AM CDT | Heat Advisory | DMX | 16 hr |
| Aug 11, 3:55 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 11, 9:07 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Aug 24, 12:49 AM CDT | Special Weather Statement | DMX | 41 min |
| Aug 24, 12:59 AM CDT | Severe Thunderstorm Warning | DMX | 46 min |
| Aug 24, 3:51 AM CDT | Flash Flood Watch | DMX | 24 hr |
| Sep 7, 2:47 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 15, 3:35 PM CDT | Flash Flood Watch | DMX | 13 hr |
| Sep 19, 5:07 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Oct 6, 1:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Oct 6, 2:12 PM CDT | Tornado Watch | SPC | 7 hr |
| Oct 6, 7:42 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Oct 12, 3:53 AM CDT | Frost Advisory | DMX | 29 hr |
| Oct 15, 3:24 PM CDT | Dense Fog Advisory | DMX | 20 hr |
| Oct 20, 3:22 PM CDT | Frost Advisory | DMX | 17 hr |
| Nov 1, 11:46 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Nov 17, 3:42 PM CST | Wind Advisory | DMX | 38 hr |
| Dec 5, 3:53 AM CST | Dense Fog Advisory | DMX | 5 hr |
| Dec 15, 11:43 AM CST | Winter Weather Advisory | DMX | 57 hr |
| Dec 16, 4:33 AM CST | Wind Chill Advisory | DMX | 55 hr |
| Dec 24, 1:50 AM CST | Dense Fog Advisory | DMX | 26 hr |
| Dec 29, 3:40 AM CST | Wind Advisory | DMX | 13 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 | 4 |
| Severe Thunderstorm Watch | 7 |
| Tornado Watch | 4 |
| Mesoscale Discussion | 25 |
| Special Weather Statement | 4 |
| Flooding | |
| Flash Flood Warning | 1 |
| Flash Flood Watch | 8 |
| Winter | |
| Winter Weather Advisory | 4 |
| Heat | |
| Excessive Heat Warning | 1 |
| Excessive Heat Watch | 2 |
| Heat Advisory | 4 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 1 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 4 |
| Wind and dust | |
| Wind Advisory | 5 |
| Fog and smoke | |
| Dense Fog Advisory | 10 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20152017
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.