Tornado Warnings in South Dakota, 2010

By month

22 of 60 tornado warnings covering South Dakota in 2010 had a tornado report inside them; 36 of 45 tornado reports fell inside a warning, on average 20 minutes after it went out.

South Dakota, 2010

Each office's whole area, 2010

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.

• Brule County9
• Ziebach County7
• Aurora County7
• Edmunds County6
• McPherson County5
• Charles Mix County5
• Douglas County5
• Walworth County4
• Todd County3
• Tripp County3
• Custer County3
• Perkins County3
• Gregory County3
• Dewey County3
• Hutchinson County3
• Sanborn County3
• Davison County3
• Potter County2
• Campbell County2
• Faulk County2
• Hyde County2
• Brown County2
• Spink County2
• Fall River County2
• Meade County2
• Pennington County2
• Union County2
• Beadle County2
• Bennett County2
• Miner County2
• Lyman County2
• Hanson County2
• Sully County1
• Hand County1
• Mellette County1
• Lincoln County1
• Deuel County1
• McCook County1
• Turner County1
• Kingsbury County1

1. May 23, 20108tornado warnings
2. May 24, 20108tornado warnings
3. June 26, 20107tornado warnings
4. July 6, 20106tornado warnings
5. June 17, 20104tornado warnings
6. May 22, 20103tornado warnings
7. June 16, 20103tornado warnings
8. July 7, 20103tornado warnings
9. July 24, 20103tornado warnings
10. June 23, 20102tornado warnings
11. July 23, 20102tornado warnings
12. May 29, 20101tornado warnings

Alerts in force nowTornadoes on recordThe radar archive20092011

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.