Alert archive / South Dakota / Tornado Warnings
Tornado Warnings in South Dakota, 2012
20 tornado warnings in 2012. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of tornado warnings reaches back to 1986.
Tornado Warnings by county
Each county as a circle sized by its count in 2012. Tap one for its archive.
- Tornado Warnings
- 20
- Busiest month
- June15 tornado warnings
- Busiest day
- June 17, 20124 tornado warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
5 of 20 tornado warnings covering South Dakota in 2012 had a tornado report inside them; 6 of 12 tornado reports fell inside a warning, on average 17 minutes after it went out.
South Dakota, 2012
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 20 | 5 | 75% | 12 | 50% | 17 min |
Each office's whole area, 2012
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 21 | 7 | 67% | 15 | 73% | 12 min |
| NWS Rapid City, SD: tornado warnings | 5 | 1 | 80% | 4 | 50% | 15 min |
| NWS Aberdeen, SD: tornado warnings | 13 | 5 | 62% | 9 | 56% | 16 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 | Counties | Lasted |
|---|---|---|---|---|
| Mar 18, 10:20 PM CDT | Tornado Warning | UNR | Todd | 25 min |
| Apr 15, 2:56 PM CDT | Tornado Warning | FSD | Bon Homme | 34 min |
| Jun 1, 7:31 PM CDT | Tornado Warning | ABR | Clark | 29 min |
| Jun 1, 8:04 PM CDT | Tornado Warning | ABR | Clark | 26 min |
| Jun 1, 8:50 PM CDT | Tornado Warning | ABR | Clark, Hamlin | 25 min |
| Jun 7, 3:54 PM CDT | Tornado Warning | UNR | Custer | 28 min |
| Jun 9, 10:16 PM CDT | Tornado Warning | UNR | Haakon, Pennington, Ziebach | 33 min |
| Jun 13, 7:35 PM CDT | Tornado Warning | FSD | Brule, Charles Mix | 40 min |
| Jun 13, 8:10 PM CDT | Tornado Warning | FSD | Brule, Charles Mix | 35 min |
| Jun 17, 5:34 PM CDT | Tornado Warning | ABR | Marshall | 26 min |
| Jun 17, 5:59 PM CDT | Tornado Warning | ABR | Marshall, Roberts | 31 min |
| Jun 17, 6:13 PM CDT | Tornado Warning | ABR | Brown, Day | 23 min |
| Jun 17, 6:46 PM CDT | Tornado Warning | ABR | Roberts | 34 min |
| Jun 17, 7:48 PM CDT | Tornado Warning | ABR | Grant, Roberts | 27 min |
| Jun 17, 8:11 PM CDT | Tornado Warning | ABR | Codington, Deuel, Hamlin | 34 min |
| Jun 22, 9:03 PM CDT | Tornado Warning | UNR | Fall River | 42 min |
| Jun 22, 9:32 PM CDT | Tornado Warning | UNR | Fall River | 58 min |
| Aug 3, 4:21 PM CDT | Tornado Warning | ABR | Edmunds | 24 min |
| Aug 3, 4:43 PM CDT | Tornado Warning | ABR | Edmunds, Faulk | 26 min |
| Aug 3, 5:40 PM CDT | Tornado Warning | ABR | Spink | 50 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Clark County3
- Roberts County3
- Hamlin County2
- Brule County2
- Charles Mix County2
- Marshall County2
- Fall River County2
- Edmunds County2
- Todd County1
- Bon Homme County1
- Custer County1
- Haakon County1
- Pennington County1
- Ziebach County1
- Brown County1
- Day County1
- Grant County1
- Codington County1
- Deuel County1
- Faulk County1
- Spink County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20112013
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.