Tornado Warnings in South Dakota, 2020

By month

6 of 37 tornado warnings covering South Dakota in 2020 had a tornado report inside them; 7 of 29 tornado reports fell inside a warning, on average 15 minutes after it went out.

South Dakota, 2020

Each office's whole area, 2020

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.

• Kingsbury County6
• Miner County5
• Faulk County4
• Hanson County4
• Edmunds County3
• Hutchinson County3
• McPherson County3
• Lawrence County3
• Charles Mix County2
• Davison County2
• McCook County2
• Meade County2
• Bennett County2
• Brookings County2
• Beadle County2
• Brown County1
• Bon Homme County1
• Douglas County1
• Sanborn County1
• Perkins County1
• Spink County1
• Potter County1
• Walworth County1
• Pennington County1
• Oglala Lakota County1
• Butte County1
• Tripp County1
• Marshall County1
• Deuel County1

1. June 9, 202011tornado warnings
2. August 28, 20206tornado warnings
3. July 6, 20204tornado warnings
4. June 8, 20203tornado warnings
5. August 31, 20202tornado warnings
6. June 7, 20201tornado warnings
7. June 30, 20201tornado warnings
8. July 5, 20201tornado warnings
9. July 7, 20201tornado warnings
10. July 8, 20201tornado warnings
11. July 10, 20201tornado warnings
12. July 11, 20201tornado warnings

Alerts in force nowTornadoes on recordThe radar archive20192021

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.