Tornado Warnings in South Dakota, 2018

By month

8 of 30 tornado warnings covering South Dakota in 2018 had a tornado report inside them; 10 of 22 tornado reports fell inside a warning, on average 14 minutes after it went out.

South Dakota, 2018

Each office's whole area, 2018

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.

• Harding County6
• Miner County4
• Hand County4
• Butte County3
• Perkins County3
• Ziebach County3
• Spink County3
• Hyde County2
• Sanborn County2
• Aurora County2
• Kingsbury County1
• Meade County1
• Hutchinson County1
• Lake County1
• Roberts County1
• Lawrence County1
• Haakon County1
• Dewey County1
• Bennett County1
• Jackson County1
• Oglala Lakota County1
• McCook County1
• Minnehaha County1
• Faulk County1
• Union County1

1. June 29, 20185tornado warnings
2. June 17, 20183tornado warnings
3. June 23, 20183tornado warnings
4. July 4, 20183tornado warnings
5. August 5, 20183tornado warnings
6. June 1, 20182tornado warnings
7. June 10, 20182tornado warnings
8. June 24, 20182tornado warnings
9. May 9, 20181tornado warnings
10. June 6, 20181tornado warnings
11. June 11, 20181tornado warnings
12. July 3, 20181tornado warnings

Alerts in force nowTornadoes on recordThe radar archive20172019

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.