Tornado Warnings in South Dakota, 2008

By month

22 of 74 tornado warnings covering South Dakota in 2008 had a tornado report inside them; 29 of 35 tornado reports fell inside a warning, on average 13 minutes after it went out.

South Dakota, 2008

Each office's whole area, 2008

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.

• Dewey County11
• Minnehaha County9
• Turner County7
• Hand County7
• Lincoln County5
• Ziebach County5
• Faulk County5
• Hyde County4
• Fall River County4
• Edmunds County4
• Lyman County4
• Spink County3
• Bon Homme County3
• Clay County3
• Union County3
• Moody County3
• Tripp County3
• McCook County2
• Haakon County2
• Yankton County2
• Bennett County2
• Lake County2
• Lawrence County2
• Pennington County2
• Custer County2
• Potter County2
• Sully County2
• Gregory County2
• Brown County1
• Jackson County1
• Walworth County1
• Corson County1
• Jerauld County1
• Hutchinson County1
• Aurora County1
• Davison County1
• Hanson County1
• Brule County1
• Charles Mix County1
• Buffalo County1

1. June 27, 20089tornado warnings
2. July 29, 20088tornado warnings
3. May 24, 20087tornado warnings
4. May 2, 20085tornado warnings
5. June 6, 20085tornado warnings
6. May 29, 20084tornado warnings
7. May 30, 20084tornado warnings
8. July 18, 20084tornado warnings
9. July 23, 20083tornado warnings
10. August 11, 20083tornado warnings
11. May 1, 20082tornado warnings
12. June 1, 20082tornado warnings

Alerts in force nowTornadoes on recordThe radar archive20072009

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.