Alert archive / South Dakota / Clark County
Weather alerts in Clark County, South Dakota, 2020
107 weather alerts in 2020, 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 2020. Tap one for its archive.
- Alerts
- 107
- Warnings
- 22
- Watches
- 15
- Advisories
- 45
- Busiest month
- June23 alerts
- Busiest day
- July 9, 20208 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, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 12 | 10 | 17% | 2 | 100% | 37 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Aberdeen, SD: tornado warnings | 11 | 3 | 73% | 16 | 19% | 6 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 262 | 160 | 39% | 356 | 78% | 19 min |
| NWS Aberdeen, SD: flash flood warnings | 4 | 1 | 75% | 1 | 100% | 205 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 3, 10:31 AM CST | Winter Weather Advisory | ABR | 3 hr |
| Jan 4, 1:29 PM CST | Wind Advisory | ABR | 23 hr |
| Jan 10, 2:25 PM CST | Wind Chill Advisory | ABR | 22 hr |
| Jan 15, 3:54 AM CST | Wind Chill Advisory | ABR | 32 hr |
| Jan 15, 2:34 PM CST | Winter Storm Watch | ABR | 37 hr |
| Jan 16, 1:35 PM CST | Winter Storm Warning | ABR | 34 hr |
| Jan 17, 3:48 AM CST | Blizzard Warning | ABR | 38 hr |
| Jan 17, 6:32 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Jan 18, 3:38 AM CST | Wind Chill Advisory | ABR | 32 hr |
| Jan 24, 3:55 AM CST | Dense Fog Advisory | ABR | 31 hr |
| Jan 26, 4:25 AM CST | Dense Fog Advisory | ABR | 3 hr |
| Jan 26, 1:16 PM CST | Winter Weather Advisory | ABR | 11 hr |
| Jan 29, 3:02 PM CST | Dense Fog Advisory | ABR | 21 hr |
| Jan 30, 12:06 PM CST | Dense Fog Advisory | ABR | 21 hr |
| Feb 7, 10:45 AM CST | Winter Storm Watch | ABR | 24 hr |
| Feb 8, 10:28 AM CST | Winter Storm Warning | ABR | 21 hr |
| Feb 8, 7:46 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Feb 11, 2:38 PM CST | Blizzard Warning | ABR | 21 hr |
| Feb 11, 2:38 PM CST | Wind Chill Warning | ABR | 43 hr |
| Feb 11, 2:38 PM CST | Winter Weather Advisory | ABR | 27 hr |
| Feb 13, 9:38 AM CST | Wind Chill Advisory | ABR | 2 hr |
| Feb 13, 2:51 PM CST | Wind Chill Advisory | ABR | 16 hr |
| Feb 14, 2:26 AM CST | Wind Advisory | ABR | 16 hr |
| Feb 17, 1:14 AM CST | Dense Fog Advisory | ABR | 8 hr |
| Feb 19, 2:19 PM CST | Wind Chill Advisory | ABR | 19 hr |
| Feb 28, 9:20 PM CST | Dense Fog Advisory | ABR | 12 hr |
| Mar 4, 2:44 PM CST | Wind Advisory | ABR | 27 hr |
| Mar 19, 3:22 AM CDT | Wind Advisory | ABR | 21 hr |
| Apr 1, 4:00 AM CDT | Winter Storm Watch | ABR | 11 hr |
| Apr 1, 4:00 AM CDT | Winter Weather Advisory | ABR | 51 hr |
| Apr 1, 2:44 PM CDT | Winter Storm Warning | ABR | 24 hr |
| Apr 8, 3:14 AM CDT | Wind Advisory | ABR | 17 hr |
| Apr 9, 8:44 AM CDT | Snow Squall Warning | ABR | 61 min |
| Apr 9, 9:43 AM CDT | Snow Squall Warning | ABR | 62 min |
| Apr 20, 3:34 AM CDT | Wind Advisory | ABR | 15 hr |
| May 8, 9:36 PM CDT | Wind Advisory | ABR | 23 hr |
| Jun 4, 7:56 PM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Jun 6, 8:29 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 6, 9:11 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 7, 2:04 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 8, 3:16 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 8, 5:56 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 8, 9:13 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 9, 12:46 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 14, 3:21 AM CDT | Wind Advisory | ABR | 16 hr |
| Jun 16, 3:16 AM CDT | Wind Advisory | ABR | 18 hr |
| Jun 17, 5:26 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 17, 6:29 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 17, 11:16 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 17, 11:50 PM CDT | Special Weather Statement | ABR | 55 min |
| Jun 20, 1:18 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jun 20, 3:20 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 20, 7:28 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 20, 7:30 PM CDT | Severe Thunderstorm Warning | ABR | 45 min |
| Jun 25, 1:16 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Jun 25, 3:30 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 28, 3:41 PM CDT | Heat Advisory | ABR | 28 hr |
| Jun 30, 5:25 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 6:04 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 8:38 PM CDT | Mesoscale Discussion | SPC | 67 min |
| Jul 5, 8:33 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jul 8, 4:15 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 8, 9:04 PM CDT | Severe Thunderstorm Warning | ABR | 41 min |
| Jul 8, 9:25 PM CDT | Severe Thunderstorm Warning | ABR | 50 min |
| Jul 8, 9:41 PM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Jul 8, 9:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jul 8, 10:26 PM CDT | Severe Thunderstorm Warning | ABR | 25 min |
| Jul 8, 10:32 PM CDT | Severe Thunderstorm Warning | ABR | 43 min |
| Jul 8, 11:07 PM CDT | Areal Flood Warning | ABR | 9 hr |
| Jul 8, 11:15 PM CDT | Severe Thunderstorm Warning | ABR | 20 min |
| Jul 17, 5:39 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 17, 10:25 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 20, 12:16 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Jul 20, 5:31 PM CDT | Special Weather Statement | ABR | 44 min |
| Jul 20, 6:01 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Jul 23, 3:03 AM CDT | Heat Advisory | ABR | 65 hr |
| Jul 26, 1:03 AM CDT | Severe Thunderstorm Warning | ABR | 42 min |
| Jul 26, 2:02 AM CDT | Mesoscale Discussion | SPC | 88 min |
| Jul 31, 8:21 PM CDT | Severe Thunderstorm Warning | ABR | 39 min |
| Aug 8, 10:10 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 9, 2:00 AM CDT | Severe Thunderstorm Warning | ABR | 17 min |
| Aug 12, 3:29 AM CDT | Special Weather Statement | ABR | 61 min |
| Aug 25, 3:23 AM CDT | Heat Advisory | ABR | 17 hr |
| Aug 27, 10:20 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 28, 1:11 AM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Aug 30, 4:55 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 30, 8:00 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 2, 3:24 AM CDT | Wind Advisory | ABR | 24 hr |
| Sep 9, 12:52 PM CDT | Frost Advisory | ABR | 20 hr |
| Sep 29, 2:30 PM CDT | Wind Advisory | ABR | 30 hr |
| Oct 1, 3:10 AM CDT | Frost Advisory | ABR | 29 hr |
| Oct 3, 2:21 PM CDT | Frost Advisory | ABR | 19 hr |
| Oct 13, 3:52 PM CDT | Wind Advisory | ABR | 27 hr |
| Oct 19, 3:24 PM CDT | Winter Weather Advisory | ABR | 28 hr |
| Oct 21, 3:08 PM CDT | Winter Weather Advisory | ABR | 30 hr |
| Oct 23, 2:35 PM CDT | Winter Weather Advisory | ABR | 48 hr |
| Oct 30, 1:47 PM CDT | Wind Advisory | ABR | 30 hr |
| Nov 7, 1:21 PM CST | Wind Advisory | ABR | 29 hr |
| Nov 9, 8:14 AM CST | Winter Weather Advisory | ABR | 2 hr |
| Nov 10, 9:42 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Dec 11, 8:35 PM CST | Dense Fog Advisory | ABR | 15 hr |
| Dec 21, 5:23 AM CST | Wind Advisory | ABR | 9 hr |
| Dec 21, 2:01 PM CST | High Wind Watch | ABR | 25 hr |
| Dec 22, 2:23 PM CST | Blizzard Warning | ABR | 31 hr |
| Dec 23, 2:38 PM CST | Wind Chill Advisory | ABR | 21 hr |
| Dec 26, 6:32 AM CST | Dense Fog Advisory | ABR | 3 hr |
| Dec 28, 3:56 AM CST | Winter Weather Advisory | ABR | 44 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 | 12 |
| Severe Thunderstorm Watch | 11 |
| Mesoscale Discussion | 22 |
| Special Weather Statement | 3 |
| Flooding | |
| Areal Flood Warning | 1 |
| Winter | |
| Blizzard Warning | 3 |
| Snow Squall Warning | 2 |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 3 |
| Winter Weather Advisory | 9 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Wind Chill Warning | 1 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 7 |
| Wind and dust | |
| High Wind Watch | 1 |
| Wind Advisory | 15 |
| 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 archive20192021
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.