Alert archive / Iowa / Clayton County
Weather alerts in Clayton County, Iowa, 2017
138 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Clayton County and its neighbors
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 138
- Warnings
- 45
- Watches
- 14
- Advisories
- 30
- Busiest month
- July41 alerts
- Busiest day
- July 12, 201718 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 4 tornado warnings covering Clayton County in 2017 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 22 minutes after it went out.
Clayton County, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 1 | 75% | 1 | 100% | 22 min |
| Severe thunderstorm warnings | 18 | 16 | 11% | 32 | 72% | 19 min |
| Flash flood warnings | 4 | 4 | 0% | 8 | 100% | 263 min |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS La Crosse, WI: tornado warnings | 22 | 4 | 82% | 14 | 36% | 8 min |
| NWS La Crosse, WI: severe thunderstorm warnings | 184 | 120 | 35% | 500 | 85% | 23 min |
| NWS La Crosse, WI: flash flood warnings | 20 | 13 | 35% | 58 | 78% | 196 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 4, 2:17 PM CST | Wind Chill Advisory | ARX | 44 hr |
| Jan 9, 3:30 AM CST | Winter Weather Advisory | ARX | 39 hr |
| Jan 15, 10:59 AM CST | Winter Weather Advisory | ARX | 49 hr |
| Jan 19, 1:27 AM CST | Dense Fog Advisory | ARX | 11 hr |
| Jan 19, 3:15 PM CST | Dense Fog Advisory | ARX | 15 hr |
| Jan 20, 3:09 PM CST | Dense Fog Advisory | ARX | 45 hr |
| Jan 22, 2:44 PM CST | Winter Storm Watch | ARX | 38 hr |
| Jan 23, 3:11 PM CST | Winter Weather Advisory | ARX | 57 hr |
| Jan 25, 5:52 PM CST | Winter Weather Advisory | ARX | 6 hr |
| Feb 7, 4:57 AM CST | Dense Fog Advisory | ARX | 7 hr |
| Feb 21, 7:07 AM CST | Dense Fog Advisory | ARX | 3 hr |
| Feb 23, 3:03 PM CST | Winter Weather Advisory | ARX | 39 hr |
| Feb 23, 8:38 PM CST | River Flood Warning | ARX | 3 days |
| Feb 28, 9:41 AM CST | River Flood Warning | ARX | 4 days |
| Feb 28, 7:09 PM CST | Dense Fog Advisory | ARX | 5 hr |
| Mar 6, 3:59 AM CST | Wind Advisory | ARX | 41 hr |
| Mar 6, 1:54 PM CST | Tornado Watch | SPC | 8 hr |
| Mar 6, 6:11 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Mar 6, 7:42 PM CST | Mesoscale Discussion | SPC | 63 min |
| Mar 6, 8:16 PM CST | Special Weather Statement | ARX | 44 min |
| Mar 6, 8:48 PM CST | Special Weather Statement | ARX | 42 min |
| Mar 6, 9:12 PM CST | Severe Thunderstorm Warning | ARX | 63 min |
| Mar 8, 2:49 AM CST | Wind Advisory | ARX | 13 hr |
| Mar 10, 2:53 PM CST | Winter Storm Watch | ARX | 36 hr |
| Mar 12, 4:03 AM CDT | Winter Storm Warning | ARX | 30 hr |
| Mar 23, 3:53 PM CDT | Severe Thunderstorm Warning | ARX | 37 min |
| Mar 23, 4:15 PM CDT | Special Weather Statement | DVN | 45 min |
| Mar 23, 4:26 PM CDT | Severe Thunderstorm Warning | ARX | 49 min |
| Mar 23, 4:42 PM CDT | Severe Thunderstorm Warning | ARX | 33 min |
| Apr 15, 5:06 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Apr 19, 10:59 PM CDT | Special Weather Statement | ARX | 61 min |
| Apr 19, 11:39 PM CDT | Special Weather Statement | ARX | 51 min |
| Apr 27, 3:19 AM CDT | Frost Advisory | ARX | 29 hr |
| May 2, 3:46 AM CDT | Frost Advisory | ARX | 28 hr |
| May 11, 4:56 AM CDT | Dense Fog Advisory | ARX | 4 hr |
| May 15, 5:11 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| May 15, 7:09 PM CDT | Severe Thunderstorm Warning | ARX | 51 min |
| May 15, 7:19 PM CDT | Mesoscale Discussion | SPC | 56 min |
| May 15, 7:27 PM CDT | Severe Thunderstorm Warning | ARX | 48 min |
| May 17, 12:23 PM CDT | Mesoscale Discussion | SPC | 97 min |
| May 17, 2:38 PM CDT | Mesoscale Discussion | SPC | 97 min |
| May 17, 3:13 PM CDT | Tornado Watch | SPC | 9 hr |
| May 17, 4:01 PM CDT | Severe Thunderstorm Warning | ARX | 44 min |
| May 17, 6:05 PM CDT | Mesoscale Discussion | SPC | 55 min |
| May 17, 6:41 PM CDT | Severe Thunderstorm Warning | ARX | 64 min |
| May 17, 7:00 PM CDT | Severe Thunderstorm Warning | ARX | 75 min |
| May 22, 9:44 AM CDT | Special Weather Statement | ARX | 61 min |
| May 23, 10:45 AM CDT | River Flood Warning | ARX | 9 days |
| May 24, 11:19 AM CDT | River Flood Warning | ARX | 8 days |
| May 27, 5:27 AM CDT | Dense Fog Advisory | ARX | 5 hr |
| Jun 12, 11:47 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 12, 5:52 PM CDT | Special Weather Statement | ARX | 53 min |
| Jun 12, 7:03 PM CDT | Special Weather Statement | ARX | 42 min |
| Jun 14, 11:28 AM CDT | Special Weather Statement | ARX | 77 min |
| Jun 14, 12:06 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 14, 12:08 PM CDT | Special Weather Statement | ARX | 52 min |
| Jun 15, 6:39 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 15, 7:11 PM CDT | Special Weather Statement | ARX | 34 min |
| Jun 16, 3:29 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 16, 3:53 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 16, 6:56 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jun 22, 8:22 AM CDT | Areal Flood Advisory | ARX | 3 hr |
| Jun 22, 8:26 AM CDT | Special Weather Statement | ARX | 49 min |
| Jun 22, 9:09 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 28, 2:53 PM CDT | Tornado Watch | SPC | 9 hr |
| Jun 28, 3:38 PM CDT | Special Weather Statement | ARX | 52 min |
| Jun 28, 4:34 PM CDT | Special Weather Statement | ARX | 56 min |
| Jun 28, 4:49 PM CDT | Tornado Warning | ARX | 26 min |
| Jun 28, 5:11 PM CDT | Severe Thunderstorm Warning | ARX | 64 min |
| Jun 28, 5:29 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 28, 5:36 PM CDT | Severe Thunderstorm Warning | ARX | 54 min |
| Jun 28, 5:51 PM CDT | Flash Flood Warning | ARX | 3 hr |
| Jun 28, 6:04 PM CDT | Special Weather Statement | ARX | 26 min |
| Jun 28, 6:19 PM CDT | Severe Thunderstorm Warning | ARX | 26 min |
| Jun 28, 8:29 PM CDT | River Flood Warning | ARX | 49 hr |
| Jun 28, 8:29 PM CDT | River Flood Warning | ARX | 55 hr |
| Jun 29, 6:42 AM CDT | Areal Flood Warning | ARX | 6 hr |
| Jun 29, 3:48 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jul 9, 9:10 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Jul 9, 9:40 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 9, 11:45 PM CDT | Mesoscale Discussion | SPC | 60 min |
| Jul 11, 12:20 PM CDT | Flash Flood Watch | ARX | 19 hr |
| Jul 11, 7:46 PM CDT | Special Weather Statement | ARX | 44 min |
| Jul 11, 8:35 PM CDT | Special Weather Statement | ARX | 70 min |
| Jul 11, 9:19 PM CDT | Tornado Warning | ARX | 26 min |
| Jul 11, 9:26 PM CDT | Areal Flood Advisory | ARX | 3 hr |
| Jul 11, 9:44 PM CDT | Severe Thunderstorm Warning | ARX | 61 min |
| Jul 11, 9:49 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 11, 10:12 PM CDT | Tornado Warning | ARX | 18 min |
| Jul 11, 10:14 PM CDT | Flash Flood Warning | ARX | 6 hr |
| Jul 12, 1:40 AM CDT | River Flood Warning | ARX | 24 hr |
| Jul 12, 1:40 AM CDT | River Flood Warning | ARX | 24 hr |
| Jul 12, 4:22 AM CDT | Areal Flood Warning | ARX | 6 hr |
| Jul 12, 8:44 AM CDT | Special Weather Statement | ARX | 31 min |
| Jul 12, 9:13 AM CDT | Special Weather Statement | ARX | 17 min |
| Jul 12, 9:18 AM CDT | Severe Thunderstorm Warning | ARX | 42 min |
| Jul 12, 9:44 AM CDT | Severe Thunderstorm Warning | ARX | 22 min |
| Jul 12, 10:12 AM CDT | Areal Flood Warning | ARX | 3 hr |
| Jul 12, 3:33 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 12, 6:19 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jul 19, 3:29 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 19, 5:11 PM CDT | Mesoscale Discussion | SPC | 34 min |
| Jul 19, 5:25 PM CDT | Severe Thunderstorm Warning | ARX | 80 min |
| Jul 19, 5:54 PM CDT | Tornado Warning | ARX | 24 min |
| Jul 19, 6:32 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jul 19, 8:19 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jul 20, 1:16 AM CDT | Mesoscale Discussion | SPC | 119 min |
| Jul 20, 11:31 AM CDT | Flash Flood Watch | ARX | 40 hr |
| Jul 21, 4:52 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jul 21, 5:08 PM CDT | Severe Thunderstorm Warning | ARX | 35 min |
| Jul 21, 5:57 PM CDT | Severe Thunderstorm Warning | ARX | 48 min |
| Jul 21, 6:45 PM CDT | Special Weather Statement | ARX | 60 min |
| Jul 21, 6:54 PM CDT | Flash Flood Warning | ARX | 15 hr |
| Jul 21, 9:06 PM CDT | River Flood Warning | ARX | 38 hr |
| Jul 21, 9:06 PM CDT | River Flood Warning | ARX | 63 hr |
| Jul 21, 10:18 PM CDT | Flash Flood Warning | ARX | 12 hr |
| Jul 22, 9:56 AM CDT | Areal Flood Warning | ARX | 24 hr |
| Jul 22, 10:09 AM CDT | Areal Flood Warning | ARX | 24 hr |
| Jul 23, 9:44 AM CDT | Areal Flood Warning | ARX | 19 hr |
| Aug 3, 7:52 AM CDT | Special Weather Statement | ARX | 23 min |
| Aug 3, 10:00 AM CDT | Special Weather Statement | ARX | 60 min |
| Aug 3, 2:19 PM CDT | Special Weather Statement | ARX | 41 min |
| Aug 3, 3:10 PM CDT | Special Weather Statement | ARX | 50 min |
| Aug 16, 2:35 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 30, 4:51 AM CDT | Dense Fog Advisory | ARX | 4 hr |
| Sep 20, 3:17 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Sep 22, 10:24 AM CDT | Heat Advisory | ARX | 9 hr |
| Oct 23, 11:20 AM CDT | Wind Advisory | ARX | 28 hr |
| Oct 27, 3:45 AM CDT | Freeze Warning | ARX | 30 hr |
| Oct 27, 2:57 PM CDT | Freeze Warning | ARX | 42 hr |
| Nov 2, 5:27 AM CDT | Dense Fog Advisory | ARX | 7 hr |
| Nov 11, 8:50 AM CST | Winter Weather Advisory | ARX | 3 hr |
| Nov 12, 9:43 PM CST | Dense Fog Advisory | ARX | 12 hr |
| Nov 14, 3:05 PM CST | Dense Fog Advisory | ARX | 7 hr |
| Dec 3, 2:48 PM CST | Wind Advisory | ARX | 51 hr |
| Dec 4, 4:18 PM CST | Special Weather Statement | ARX | 42 min |
| Dec 24, 2:07 PM CST | Wind Chill Advisory | ARX | 70 hr |
| Dec 29, 3:26 PM CST | Wind Chill Advisory | ARX | 69 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 | 18 |
| Tornado Warning | 4 |
| Severe Thunderstorm Watch | 7 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 24 |
| Special Weather Statement | 25 |
| Flooding | |
| Areal Flood Warning | 6 |
| Flash Flood Warning | 4 |
| River Flood Warning | 10 |
| Flash Flood Watch | 2 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 6 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 2 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| Wind Advisory | 4 |
| Fog and smoke | |
| Dense Fog Advisory | 12 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20162018
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.