Alert archive / South Dakota / Clark County
Weather alerts in Clark County, South Dakota, 2009
103 weather alerts in 2009, 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 2009. Tap one for its archive.
- Alerts
- 103
- Warnings
- 22
- Watches
- 19
- Advisories
- 30
- Busiest month
- July19 alerts
- Busiest day
- July 7, 20096 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 1 tornado warnings covering Clark County in 2009 had a tornado report inside them.
Clark County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 11 | 10 | 9% | 9 | 89% | 20 min |
| Flash flood warnings | 1 | 1 | 0% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Aberdeen, SD: tornado warnings | 24 | 7 | 71% | 10 | 80% | 19 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 147 | 86 | 41% | 173 | 71% | 19 min |
| NWS Aberdeen, SD: flash flood warnings | 18 | 8 | 56% | 25 | 72% | 60 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, 3:33 PM CST | Winter Weather Advisory | ABR | 30 hr |
| Jan 3, 2:57 PM CST | Wind Chill Advisory | ABR | 20 hr |
| Jan 8, 4:58 AM CST | Winter Weather Advisory | ABR | 34 hr |
| Jan 11, 3:58 AM CST | Blizzard Watch | ABR | 11 hr |
| Jan 11, 2:54 PM CST | Blizzard Warning | ABR | 27 hr |
| Jan 12, 5:34 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 12, 10:56 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 12, 7:12 PM CST | Wind Chill Advisory | ABR | 5 hr |
| Jan 13, 4:16 AM CST | Winter Weather Advisory | ABR | 16 hr |
| Jan 13, 11:50 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 13, 7:47 PM CST | Wind Chill Advisory | ABR | 24 hr |
| Jan 14, 5:30 AM CST | Wind Chill Warning | ABR | 9 hr |
| Jan 14, 8:14 PM CST | Wind Chill Advisory | ABR | 8 hr |
| Jan 23, 3:49 AM CST | Wind Chill Advisory | ABR | 32 hr |
| Jan 31, 2:08 PM CST | Wind Advisory | ABR | 5 hr |
| Feb 10, 4:09 AM CST | Dense Fog Advisory | ABR | 3 hr |
| Feb 17, 4:33 AM CST | Dense Fog Advisory | ABR | 5 hr |
| Feb 20, 2:54 AM CST | Winter Weather Advisory | ABR | 18 hr |
| Feb 24, 3:16 PM CST | Winter Storm Watch | ABR | 12 hr |
| Feb 25, 3:41 AM CST | Winter Storm Warning | ABR | 40 hr |
| Feb 25, 10:20 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 26, 3:13 PM CST | Wind Chill Advisory | ABR | 21 hr |
| Mar 8, 11:42 AM CDT | Winter Storm Watch | ABR | 28 hr |
| Mar 9, 3:41 AM CDT | Blizzard Watch | ABR | 12 hr |
| Mar 9, 3:23 PM CDT | Winter Storm Warning | ABR | 32 hr |
| Mar 9, 3:23 PM CDT | Winter Weather Advisory | ABR | 23 hr |
| Mar 10, 2:22 PM CDT | Wind Chill Advisory | ABR | 22 hr |
| Mar 22, 4:19 AM CDT | Flood Watch | ABR | 27 hr |
| Mar 22, 4:24 AM CDT | Wind Advisory | ABR | 11 hr |
| Mar 28, 4:37 AM CDT | Blizzard Watch | ABR | 35 hr |
| Mar 29, 4:30 AM CDT | Blizzard Warning | ABR | 65 hr |
| Mar 30, 3:20 PM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 31, 1:22 AM CDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 31, 7:02 AM CDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 31, 1:26 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 3, 4:37 AM CDT | Winter Weather Advisory | ABR | 41 hr |
| Apr 29, 9:27 PM CDT | Mesoscale Discussion | SPC | 93 min |
| May 12, 4:13 AM CDT | Wind Advisory | ABR | 12 hr |
| May 12, 4:00 PM CDT | Wind Advisory | ABR | 29 hr |
| May 12, 8:42 PM CDT | Mesoscale Discussion | SPC | 93 min |
| May 13, 9:04 PM CDT | Wind Advisory | ABR | 2 hr |
| May 15, 3:23 PM CDT | Freeze Warning | ABR | 17 hr |
| May 25, 1:33 PM CDT | Special Weather Statement | ABR | 27 min |
| May 31, 4:52 PM CDT | Special Weather Statement | ABR | 53 min |
| May 31, 5:34 PM CDT | Severe Thunderstorm Warning | ABR | 41 min |
| May 31, 6:01 PM CDT | Severe Thunderstorm Warning | ABR | 30 min |
| Jun 16, 2:05 PM CDT | Tornado Watch | SPC | 6 hr |
| Jun 16, 3:26 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jun 16, 5:39 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jun 18, 1:50 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 18, 6:49 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jun 18, 7:06 PM CDT | Severe Thunderstorm Warning | ABR | 39 min |
| Jun 18, 7:25 PM CDT | Severe Thunderstorm Warning | ABR | 37 min |
| Jun 23, 7:24 AM CDT | Mesoscale Discussion | SPC | 96 min |
| Jun 24, 2:12 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jun 24, 6:16 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 24, 8:49 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jun 24, 9:00 PM CDT | Severe Thunderstorm Warning | ABR | 45 min |
| Jun 26, 6:24 PM CDT | Tornado Watch | SPC | 4 hr |
| Jun 26, 10:13 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jun 27, 5:02 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jul 6, 2:58 PM CDT | Mesoscale Discussion | SPC | 32 min |
| Jul 7, 10:14 AM CDT | Mesoscale Discussion | SPC | 91 min |
| Jul 7, 1:47 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jul 7, 2:13 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 7, 2:52 PM CDT | Severe Thunderstorm Warning | ABR | 68 min |
| Jul 7, 2:57 PM CDT | Tornado Warning | ABR | 63 min |
| Jul 7, 3:27 PM CDT | Severe Thunderstorm Warning | ABR | 48 min |
| Jul 8, 9:58 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 8, 11:27 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jul 9, 1:18 AM CDT | Severe Thunderstorm Warning | ABR | 42 min |
| Jul 9, 1:52 AM CDT | Severe Thunderstorm Warning | ABR | 53 min |
| Jul 9, 3:07 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 9, 3:41 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 12, 2:30 AM CDT | Mesoscale Discussion | SPC | 60 min |
| Jul 14, 1:17 AM CDT | Flash Flood Warning | ABR | 3 hr |
| Jul 20, 1:07 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 31, 1:35 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 31, 4:41 PM CDT | Severe Thunderstorm Warning | ABR | 49 min |
| Jul 31, 4:59 PM CDT | Severe Thunderstorm Warning | ABR | 46 min |
| Aug 3, 6:58 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 8, 10:52 AM CDT | Mesoscale Discussion | SPC | 23 min |
| Aug 8, 11:15 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 8, 2:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Aug 15, 11:37 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Sep 8, 2:53 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Sep 8, 7:10 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 26, 3:08 PM CDT | Wind Advisory | ABR | 28 hr |
| Sep 28, 3:49 AM CDT | Frost Advisory | ABR | 29 hr |
| Sep 30, 11:07 AM CDT | Wind Advisory | ABR | 8 hr |
| Oct 7, 2:23 PM CDT | Freeze Watch | ABR | 13 hr |
| Oct 8, 3:37 AM CDT | Freeze Warning | ABR | 30 hr |
| Oct 10, 2:51 PM CDT | Winter Storm Watch | ABR | 24 hr |
| Dec 1, 3:46 AM CST | Wind Advisory | ABR | 14 hr |
| Dec 8, 3:34 AM CST | Winter Weather Advisory | ABR | 25 hr |
| Dec 8, 3:30 PM CST | Wind Chill Advisory | ABR | 43 hr |
| Dec 13, 4:02 AM CST | Wind Chill Advisory | ABR | 8 hr |
| Dec 13, 6:19 PM CST | Winter Weather Advisory | ABR | 8 hr |
| Dec 14, 3:52 PM CST | Wind Chill Advisory | ABR | 19 hr |
| Dec 21, 2:16 PM CST | Winter Storm Watch | ABR | 14 hr |
| Dec 22, 3:58 AM CST | Winter Storm Warning | ABR | 55 hr |
| Dec 24, 10:45 AM CST | Blizzard Warning | ABR | 55 hr |
| Dec 26, 11:54 AM CST | Winter Weather Advisory | ABR | 12 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 | 1 |
| Severe Thunderstorm Watch | 8 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 30 |
| Special Weather Statement | 2 |
| Flooding | |
| Flash Flood Warning | 1 |
| Flood Watch | 1 |
| Winter | |
| Blizzard Warning | 3 |
| Winter Storm Warning | 3 |
| Blizzard Watch | 3 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 9 |
| Cold | |
| Freeze Warning | 2 |
| Wind Chill Warning | 1 |
| Freeze Watch | 1 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 10 |
| Wind and dust | |
| Wind Advisory | 8 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20082010
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.