Alert archive / Iowa / Floyd County
Weather alerts in Floyd County, Iowa, 2021
104 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Floyd County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 104
- Warnings
- 21
- Watches
- 16
- Advisories
- 33
- Busiest month
- August23 alerts
- Busiest day
- July 14, 20218 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
3 of 5 tornado warnings covering Floyd County in 2021 had a tornado report inside them; 8 of 8 tornado reports fell inside a warning, on average 21 minutes after it went out.
Floyd County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 5 | 3 | 40% | 8 | 100% | 21 min |
| Severe thunderstorm warnings | 4 | 3 | 25% | 11 | 64% | 22 min |
| Flash flood warnings | 2 | 2 | 0% | 1 | 100% | 5 min |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS La Crosse, WI: tornado warnings | 28 | 7 | 75% | 14 | 100% | 22 min |
| NWS La Crosse, WI: severe thunderstorm warnings | 117 | 58 | 50% | 269 | 75% | 30 min |
| NWS La Crosse, WI: flash flood warnings | 11 | 9 | 18% | 25 | 84% | 61 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 2, 1:55 PM CST | Dense Fog Advisory | ARX | 22 hr |
| Jan 3, 2:58 PM CST | Dense Fog Advisory | ARX | 24 hr |
| Jan 13, 2:42 PM CST | Winter Weather Advisory | ARX | 42 hr |
| Jan 22, 2:15 PM CST | Winter Weather Advisory | ARX | 43 hr |
| Jan 25, 3:21 AM CST | Winter Weather Advisory | ARX | 33 hr |
| Jan 29, 2:54 PM CST | Winter Weather Advisory | ARX | 45 hr |
| Feb 2, 2:29 PM CST | Winter Storm Watch | ARX | 23 hr |
| Feb 3, 1:53 PM CST | Winter Weather Advisory | ARX | 34 hr |
| Feb 4, 3:53 AM CST | Winter Storm Warning | ARX | 20 hr |
| Feb 5, 3:44 AM CST | Wind Chill Advisory | ARX | 3 days |
| Feb 8, 1:34 PM CST | Wind Chill Advisory | ARX | 20 hr |
| Feb 10, 2:52 PM CST | Wind Chill Advisory | ARX | 19 hr |
| Feb 11, 2:20 PM CST | Wind Chill Advisory | ARX | 46 hr |
| Feb 13, 3:15 AM CST | Wind Chill Warning | ARX | 57 hr |
| Feb 15, 11:53 AM CST | Wind Chill Advisory | ARX | 22 hr |
| Feb 20, 2:09 PM CST | Winter Weather Advisory | ARX | 32 hr |
| Feb 25, 10:11 PM CST | Dense Fog Advisory | ARX | 9 hr |
| Mar 10, 4:02 AM CST | Wind Advisory | ARX | 23 hr |
| Mar 10, 1:32 PM CST | Mesoscale Discussion | SPC | 118 min |
| Mar 10, 2:46 PM CST | Tornado Watch | SPC | 5 hr |
| Mar 10, 5:43 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Mar 13, 3:20 AM CST | Winter Storm Watch | ARX | 24 hr |
| Mar 14, 4:06 AM CDT | Winter Storm Warning | ARX | 39 hr |
| Mar 15, 1:50 AM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 21, 3:12 AM CDT | Wind Advisory | ARX | 13 hr |
| Mar 28, 1:57 PM CDT | Wind Advisory | ARX | 30 hr |
| Apr 2, 11:12 AM CDT | Red Flag Warning | ARX | 9 hr |
| Apr 5, 5:58 AM CDT | Special Weather Statement | ARX | 62 min |
| May 1, 10:24 AM CDT | Red Flag Warning | ARX | 10 hr |
| May 2, 4:20 PM CDT | Mesoscale Discussion | SPC | 115 min |
| May 7, 1:37 PM CDT | Frost Advisory | ARX | 18 hr |
| May 10, 1:52 PM CDT | Frost Advisory | ARX | 18 hr |
| May 11, 1:45 PM CDT | Frost Advisory | ARX | 18 hr |
| May 15, 1:16 PM CDT | Mesoscale Discussion | SPC | 119 min |
| May 20, 9:05 PM CDT | Mesoscale Discussion | SPC | 115 min |
| May 28, 10:36 AM CDT | Frost Advisory | ARX | 20 hr |
| Jun 11, 9:35 AM CDT | Mesoscale Discussion | SPC | 115 min |
| Jun 17, 4:26 AM CDT | Special Weather Statement | ARX | 64 min |
| Jun 17, 2:57 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Jun 17, 3:50 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 17, 10:01 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 20, 1:10 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jun 20, 1:42 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 20, 5:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Jun 25, 4:48 PM CDT | Areal Flood Advisory | ARX | 2 hr |
| Jul 6, 5:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Jul 14, 7:02 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 8:54 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 14, 9:06 AM CDT | Severe Thunderstorm Warning | ARX | 39 min |
| Jul 14, 1:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 2:35 PM CDT | Tornado Watch | SPC | 8 hr |
| Jul 14, 5:33 PM CDT | Tornado Warning | ARX | 42 min |
| Jul 14, 5:47 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Jul 14, 6:09 PM CDT | Tornado Warning | ARX | 52 min |
| Jul 27, 3:10 PM CDT | Heat Advisory | ARX | 30 hr |
| Jul 27, 7:33 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 27, 8:03 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 7, 11:03 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 3:46 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Aug 9, 12:10 AM CDT | Flash Flood Warning | ARX | 6 hr |
| Aug 9, 1:55 PM CDT | Heat Advisory | ARX | 28 hr |
| Aug 20, 10:27 PM CDT | Special Weather Statement | ARX | 48 min |
| Aug 20, 10:43 PM CDT | Special Weather Statement | ARX | 62 min |
| Aug 24, 6:00 AM CDT | Mesoscale Discussion | SPC | 90 min |
| Aug 24, 12:38 PM CDT | Special Weather Statement | ARX | 67 min |
| Aug 24, 12:44 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 24, 1:43 PM CDT | Severe Thunderstorm Warning | ARX | 47 min |
| Aug 26, 5:45 PM CDT | Flood Watch | ARX | 13 hr |
| Aug 26, 10:45 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 27, 1:53 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Aug 27, 4:01 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Aug 27, 5:15 PM CDT | Tornado Watch | SPC | 6 hr |
| Aug 27, 5:30 PM CDT | Mesoscale Discussion | SPC | 60 min |
| Aug 27, 5:34 PM CDT | Tornado Warning | ARX | 41 min |
| Aug 27, 6:09 PM CDT | Tornado Warning | ARX | 51 min |
| Aug 27, 7:38 PM CDT | Flash Flood Watch | ARX | 18 hr |
| Aug 27, 9:57 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Aug 27, 11:12 PM CDT | Flash Flood Warning | ARX | 6 hr |
| Aug 28, 4:05 AM CDT | River Flood Warning | ARX | 70 hr |
| Aug 28, 9:39 AM CDT | Areal Flood Warning | ARX | 30 hr |
| Sep 20, 12:38 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 20, 2:07 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 20, 3:55 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Sep 20, 4:06 PM CDT | Special Weather Statement | ARX | 24 min |
| Sep 20, 4:25 PM CDT | Severe Thunderstorm Warning | ARX | 50 min |
| Oct 4, 2:38 PM CDT | Dense Fog Advisory | ARX | 18 hr |
| Oct 21, 3:07 AM CDT | Freeze Warning | ARX | 30 hr |
| Oct 22, 1:56 PM CDT | Freeze Warning | ARX | 19 hr |
| Nov 13, 5:42 PM CST | Wind Advisory | ARX | 14 hr |
| Dec 5, 3:03 AM CST | Wind Advisory | ARX | 30 hr |
| Dec 8, 2:41 AM CST | Winter Storm Watch | ARX | 35 hr |
| Dec 9, 5:23 AM CST | Winter Weather Advisory | ARX | 4 hr |
| Dec 9, 1:50 PM CST | Winter Weather Advisory | ARX | 43 hr |
| Dec 13, 3:25 AM CST | High Wind Watch | ARX | 35 hr |
| Dec 14, 2:46 PM CST | High Wind Warning | ARX | 39 hr |
| Dec 15, 5:30 PM CST | Tornado Watch | SPC | 6 hr |
| Dec 15, 6:37 PM CST | Severe Thunderstorm Warning | ARX | 68 min |
| Dec 15, 6:44 PM CST | Tornado Warning | ARX | 32 min |
| Dec 15, 7:11 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Dec 24, 7:47 AM CST | Dense Fog Advisory | ARX | 6 hr |
| Dec 27, 2:38 PM CST | Winter Weather Advisory | ARX | 33 hr |
| Dec 28, 8:59 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 30, 8:47 PM CST | Dense Fog Advisory | ARX | 14 hr |
| Dec 31, 12:32 PM CST | Winter Weather Advisory | ARX | 8 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.