Alert archive / South Dakota / Aurora County
Weather alerts in Aurora County, South Dakota, 2021
94 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Aurora County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 94
- Warnings
- 27
- Watches
- 17
- Advisories
- 34
- Busiest month
- August19 alerts
- Busiest day
- August 22, 20215 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 2 tornado warnings covering Aurora County in 2021 had a tornado report inside them.
Aurora County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 11 | 5 | 55% | 5 | 100% | 14 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 24 | 3 | 88% | 8 | 50% | 10 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 176 | 117 | 34% | 292 | 85% | 20 min |
| NWS Sioux Falls, SD: flash flood warnings | 7 | 3 | 57% | 9 | 89% | 51 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, 2:30 PM CST | Dense Fog Advisory | FSD | 22 hr |
| Jan 12, 2:37 PM CST | High Wind Watch | FSD | 25 hr |
| Jan 13, 3:32 PM CST | High Wind Warning | FSD | 44 hr |
| Jan 22, 4:05 AM CST | Winter Weather Advisory | FSD | 44 hr |
| Feb 2, 9:16 PM CST | Dense Fog Advisory | FSD | 16 hr |
| Feb 12, 2:09 PM CST | Wind Chill Watch | FSD | 61 hr |
| Feb 12, 2:09 PM CST | Wind Chill Advisory | FSD | 22 hr |
| Feb 13, 3:35 AM CST | Wind Chill Warning | FSD | 3 days |
| Feb 22, 3:18 AM CST | Wind Advisory | FSD | 15 hr |
| Feb 27, 3:52 AM CST | Winter Weather Advisory | FSD | 29 hr |
| Mar 5, 4:11 AM CST | Dense Fog Advisory | FSD | 6 hr |
| Mar 6, 4:20 AM CST | Dense Fog Advisory | FSD | 4 hr |
| Mar 9, 3:55 AM CST | Winter Weather Advisory | FSD | 44 hr |
| Mar 14, 4:03 AM CDT | Winter Storm Warning | FSD | 32 hr |
| Mar 14, 4:03 AM CDT | Winter Weather Advisory | FSD | 30 hr |
| Mar 14, 6:20 PM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 27, 3:31 PM CDT | Fire Weather Watch | FSD | 23 hr |
| Mar 28, 2:40 PM CDT | Wind Advisory | FSD | 30 hr |
| Mar 28, 2:47 PM CDT | Red Flag Warning | FSD | 30 hr |
| Mar 29, 3:18 PM CDT | Red Flag Warning | FSD | 30 hr |
| Mar 30, 10:59 AM CDT | Wind Advisory | FSD | 10 hr |
| Mar 31, 2:41 PM CDT | Red Flag Warning | FSD | 31 hr |
| Apr 3, 4:09 AM CDT | Red Flag Warning | FSD | 17 hr |
| Apr 12, 9:37 AM CDT | Wind Advisory | FSD | 9 hr |
| May 3, 2:28 PM CDT | Frost Advisory | FSD | 18 hr |
| May 5, 2:24 PM CDT | Frost Advisory | FSD | 18 hr |
| May 9, 3:22 PM CDT | Frost Advisory | FSD | 17 hr |
| May 10, 3:12 PM CDT | Frost Advisory | FSD | 17 hr |
| May 30, 4:08 AM CDT | Dense Fog Advisory | FSD | 5 hr |
| Jun 10, 3:31 AM CDT | Heat Advisory | FSD | 16 hr |
| Jun 11, 12:52 AM CDT | Mesoscale Discussion | SPC | 53 min |
| Jun 11, 2:15 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 11, 3:39 AM CDT | Severe Thunderstorm Warning | FSD | 51 min |
| Jun 11, 4:37 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 15, 2:43 PM CDT | Heat Advisory | FSD | 29 hr |
| Jun 23, 7:46 PM CDT | Severe Thunderstorm Warning | FSD | 44 min |
| Jun 23, 8:05 PM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Jun 23, 8:36 PM CDT | Severe Thunderstorm Warning | FSD | 18 min |
| Jul 3, 2:15 PM CDT | Heat Advisory | FSD | 30 hr |
| Jul 5, 3:24 AM CDT | Heat Advisory | FSD | 17 hr |
| Jul 5, 1:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 8, 8:54 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 8, 9:33 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 9, 1:22 AM CDT | Severe Thunderstorm Warning | FSD | 38 min |
| Jul 9, 2:41 AM CDT | Mesoscale Discussion | SPC | 34 min |
| Jul 23, 9:07 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 23, 9:11 PM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Jul 26, 3:11 AM CDT | Excessive Heat Watch | FSD | 35 hr |
| Jul 26, 3:11 AM CDT | Heat Advisory | FSD | 42 hr |
| Jul 27, 2:22 PM CDT | Heat Advisory | FSD | 31 hr |
| Jul 31, 1:02 AM CDT | Dense Fog Advisory | FSD | 8 hr |
| Aug 6, 9:09 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 6, 10:08 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 22, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 22, 5:48 PM CDT | Severe Thunderstorm Warning | FSD | 42 min |
| Aug 22, 6:23 PM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Aug 22, 6:31 PM CDT | Tornado Watch | SPC | 3 hr |
| Aug 22, 6:47 PM CDT | Tornado Warning | FSD | 32 min |
| Aug 22, 7:21 PM CDT | Severe Thunderstorm Warning | FSD | 24 min |
| Aug 22, 8:40 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Aug 23, 2:56 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 23, 5:20 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 23, 7:38 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 23, 9:37 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Aug 26, 7:25 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 26, 8:03 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 30, 7:25 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 30, 9:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 31, 12:00 AM CDT | Flash Flood Warning | FSD | 3 hr |
| Aug 31, 12:05 AM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Sep 16, 8:16 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Oct 9, 12:04 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 9, 2:56 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Oct 9, 3:39 PM CDT | Severe Thunderstorm Warning | FSD | 51 min |
| Oct 9, 3:56 PM CDT | Tornado Warning | FSD | 34 min |
| Oct 13, 2:53 AM CDT | Wind Advisory | FSD | 20 hr |
| Oct 15, 3:30 AM CDT | Frost Advisory | FSD | 30 hr |
| Nov 10, 2:54 PM CST | High Wind Warning | FSD | 39 hr |
| Nov 10, 2:54 PM CST | Wind Advisory | FSD | 51 hr |
| Nov 13, 5:00 PM CST | High Wind Warning | FSD | 4 hr |
| Nov 13, 5:00 PM CST | Wind Advisory | FSD | 10 hr |
| Nov 17, 3:00 AM CST | Wind Advisory | FSD | 15 hr |
| Nov 22, 3:15 AM CST | Fire Weather Watch | FSD | 25 hr |
| Nov 23, 3:46 AM CST | Red Flag Warning | FSD | 14 hr |
| Dec 4, 3:11 PM CST | High Wind Warning | FSD | 30 hr |
| Dec 8, 3:31 AM CST | Winter Storm Watch | FSD | 32 hr |
| Dec 9, 11:23 AM CST | Winter Storm Warning | FSD | 40 hr |
| Dec 9, 11:23 AM CST | Winter Weather Advisory | FSD | 40 hr |
| Dec 10, 9:10 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 14, 4:04 AM CST | High Wind Watch | FSD | 11 hr |
| Dec 14, 4:04 AM CST | High Wind Warning | FSD | 47 hr |
| Dec 14, 2:28 PM CST | Winter Weather Advisory | FSD | 36 hr |
| Dec 26, 1:52 PM CST | Wind Advisory | FSD | 22 hr |
| Dec 30, 9:16 PM CST | Winter Weather Advisory | FSD | 18 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 | 11 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 9 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 16 |
| Flooding | |
| Flash Flood Warning | 1 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 7 |
| Heat | |
| Excessive Heat Watch | 1 |
| Heat Advisory | 6 |
| Cold | |
| Wind Chill Warning | 1 |
| Wind Chill Watch | 1 |
| Frost Advisory | 5 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 5 |
| High Wind Watch | 2 |
| Wind Advisory | 9 |
| Fire | |
| Red Flag Warning | 5 |
| Fire Weather Watch | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 6 |
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.