Alert archive / South Dakota / Clark County
Weather alerts in Clark County, South Dakota, 2021
97 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Clark County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 97
- Warnings
- 29
- Watches
- 14
- Advisories
- 40
- Busiest month
- August19 alerts
- Busiest day
- June 11, 20216 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Clark County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 13 | 12 | 8% | 5 | 100% | 23 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Aberdeen, SD: tornado warnings | 21 | 5 | 76% | 17 | 35% | 19 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 170 | 101 | 41% | 220 | 76% | 20 min |
| NWS Aberdeen, SD: flash flood warnings | 4 | 1 | 75% | 1 | 100% | 104 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 1, 10:59 AM CST | Dense Fog Advisory | ABR | 20 hr |
| Jan 5, 1:35 PM CST | Winter Weather Advisory | ABR | 21 hr |
| Jan 7, 2:17 PM CST | Dense Fog Advisory | ABR | 20 hr |
| Jan 8, 9:43 PM CST | Dense Fog Advisory | ABR | 14 hr |
| Jan 12, 11:23 AM CST | High Wind Watch | ABR | 27 hr |
| Jan 13, 2:43 PM CST | Winter Storm Watch | ABR | 12 hr |
| Jan 14, 2:50 AM CST | Blizzard Warning | ABR | 39 hr |
| Jan 22, 2:15 AM CST | Winter Weather Advisory | ABR | 43 hr |
| Jan 29, 2:39 PM CST | Winter Weather Advisory | ABR | 30 hr |
| Jan 31, 8:55 PM CST | Dense Fog Advisory | ABR | 68 hr |
| Feb 5, 2:59 AM CST | Wind Chill Advisory | ABR | 57 hr |
| Feb 8, 2:40 AM CST | Wind Chill Advisory | ABR | 32 hr |
| Feb 9, 2:41 PM CST | Wind Chill Advisory | ABR | 20 hr |
| Feb 10, 1:29 PM CST | Wind Chill Advisory | ABR | 3 days |
| Feb 12, 2:27 PM CST | Wind Chill Warning | ABR | 69 hr |
| Feb 15, 11:30 AM CST | Wind Chill Warning | ABR | 22 hr |
| Feb 20, 8:24 PM CST | Winter Weather Advisory | ABR | 7 hr |
| Feb 21, 8:36 PM CST | Dense Fog Advisory | ABR | 6 hr |
| Mar 9, 4:07 AM CST | Winter Weather Advisory | ABR | 44 hr |
| Mar 10, 2:29 AM CST | Winter Storm Warning | ABR | 21 hr |
| Mar 14, 3:19 AM CDT | Winter Weather Advisory | ABR | 31 hr |
| Mar 14, 6:20 PM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 15, 1:50 AM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 26, 2:41 PM CDT | Fire Weather Watch | ABR | 48 hr |
| Mar 28, 2:31 PM CDT | Wind Advisory | ABR | 32 hr |
| Mar 28, 2:36 PM CDT | Red Flag Warning | ABR | 31 hr |
| Mar 29, 9:04 PM CDT | High Wind Warning | ABR | 10 hr |
| Mar 29, 9:04 PM CDT | Wind Advisory | ABR | 21 hr |
| Mar 30, 6:11 PM CDT | Wind Advisory | ABR | 3 hr |
| Mar 31, 2:48 PM CDT | Red Flag Warning | ABR | 31 hr |
| May 5, 2:52 PM CDT | Fire Weather Watch | ABR | 13 hr |
| May 6, 3:27 AM CDT | Red Flag Warning | ABR | 17 hr |
| May 13, 10:43 PM CDT | Special Weather Statement | ABR | 47 min |
| May 24, 12:14 AM CDT | Special Weather Statement | ABR | 46 min |
| May 27, 2:46 PM CDT | Freeze Warning | ABR | 17 hr |
| Jun 10, 3:53 AM CDT | Heat Advisory | ABR | 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, 4:16 AM CDT | Severe Thunderstorm Warning | ABR | 44 min |
| Jun 11, 4:37 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 11, 4:49 AM CDT | Severe Thunderstorm Warning | ABR | 41 min |
| Jun 11, 5:02 AM CDT | Severe Thunderstorm Warning | ABR | 43 min |
| Jun 15, 2:09 PM CDT | Heat Advisory | ABR | 30 hr |
| Jul 23, 5:04 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 23, 7:02 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 25, 8:11 PM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Jul 25, 8:54 PM CDT | Severe Thunderstorm Warning | ABR | 51 min |
| Jul 26, 3:41 AM CDT | Heat Advisory | ABR | 41 hr |
| Jul 27, 3:42 AM CDT | Heat Advisory | ABR | 39 hr |
| Jul 31, 5:46 AM CDT | Dense Fog Advisory | ABR | 4 hr |
| Aug 7, 2:10 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 11:25 PM CDT | Severe Thunderstorm Warning | ABR | 50 min |
| Aug 8, 12:56 AM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Aug 8, 3:37 AM CDT | Areal Flood Warning | ABR | 5 hr |
| Aug 8, 5:02 AM CDT | Areal Flood Warning | ABR | 4 hr |
| Aug 22, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 22, 5:59 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 23, 10:11 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 23, 11:32 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Aug 26, 8:36 AM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 26, 8:45 AM CDT | Severe Thunderstorm Warning | ABR | 45 min |
| Aug 26, 9:05 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 26, 9:22 AM CDT | Severe Thunderstorm Warning | ABR | 38 min |
| Aug 26, 9:26 AM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Aug 26, 9:50 AM CDT | High Wind Warning | ABR | 5 hr |
| Aug 28, 2:32 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 28, 5:10 AM CDT | Severe Thunderstorm Warning | ABR | 65 min |
| Aug 28, 5:42 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 28, 7:08 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Sep 24, 2:16 PM CDT | Frost Advisory | ABR | 19 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, 3:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Oct 9, 4:33 PM CDT | Severe Thunderstorm Warning | ABR | 42 min |
| Oct 9, 5:18 PM CDT | Severe Thunderstorm Warning | ABR | 57 min |
| Oct 12, 3:55 PM CDT | Wind Advisory | ABR | 30 hr |
| Oct 15, 11:38 AM CDT | Freeze Warning | ABR | 22 hr |
| Oct 26, 2:55 AM CDT | Wind Advisory | ABR | 16 hr |
| Nov 4, 8:09 AM CDT | Dense Fog Advisory | ABR | 5 hr |
| Nov 10, 3:26 AM CST | Winter Storm Watch | ABR | 24 hr |
| Nov 11, 3:47 AM CST | Blizzard Warning | ABR | 32 hr |
| Nov 13, 3:26 AM CST | High Wind Warning | ABR | 20 hr |
| Nov 13, 9:57 AM CST | Winter Weather Advisory | ABR | 3 hr |
| Nov 13, 2:14 PM CST | Wind Advisory | ABR | 3 hr |
| Nov 13, 11:37 PM CST | Wind Advisory | ABR | 3 hr |
| Nov 15, 2:47 PM CST | Wind Advisory | ABR | 51 hr |
| Dec 4, 3:01 PM CST | Wind Advisory | ABR | 33 hr |
| Dec 14, 3:37 AM CST | High Wind Watch | ABR | 11 hr |
| Dec 14, 3:54 AM CST | Winter Weather Advisory | ABR | 50 hr |
| Dec 14, 2:20 PM CST | High Wind Warning | ABR | 36 hr |
| Dec 14, 2:20 PM CST | Wind Advisory | ABR | 13 hr |
| Dec 15, 3:54 AM CST | Dense Fog Advisory | ABR | 11 hr |
| Dec 17, 6:29 PM CST | Winter Weather Advisory | ABR | 6 hr |
| Dec 26, 2:12 AM CST | Winter Weather Advisory | ABR | 37 hr |
| Dec 28, 3:04 PM CST | Wind Chill Advisory | ABR | 21 hr |
| Dec 30, 2:36 PM CST | Wind Chill Advisory | ABR | 27 hr |
| Dec 30, 9:18 PM CST | Winter Weather Advisory | ABR | 15 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 | 13 |
| Severe Thunderstorm Watch | 8 |
| Mesoscale Discussion | 12 |
| Special Weather Statement | 2 |
| Flooding | |
| Areal Flood Warning | 2 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 11 |
| Heat | |
| Heat Advisory | 4 |
| Cold | |
| Freeze Warning | 2 |
| Wind Chill Warning | 2 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 6 |
| Wind and dust | |
| High Wind Warning | 4 |
| High Wind Watch | 2 |
| Wind Advisory | 10 |
| Fire | |
| Red Flag Warning | 3 |
| Fire Weather Watch | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 8 |
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.