Alert archive / South Dakota / Sully County / Severe Thunderstorm Warnings

Severe Thunderstorm Warnings in Sully County, South Dakota, 2012

17 severe thunderstorm warnings in 2012. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Sully County and its neighbors

Each county as a circle sized by its count in 2012. Tap one for its archive.

Severe Thunderstorm Warnings
17
Busiest month
June8 severe thunderstorm warnings
Busiest day
June 10, 20126 severe thunderstorm warnings

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

8 of 17 severe thunderstorm warnings covering Sully County in 2012 had a qualifying storm report inside them; 3 of 4 hail, wind and damage reports fell inside a warning, on average 31 minutes after it went out.

Sully County, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Severe thunderstorm warnings17853%475%31 min

Each office's whole area, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Aberdeen, SD: severe thunderstorm warnings18912434%27484%22 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.

IssuedProductOfficeLasted
May 2, 8:07 PM CDTSevere Thunderstorm WarningABR53 min
May 5, 8:58 AM CDTSevere Thunderstorm WarningABR47 min
May 26, 8:58 PM CDTSevere Thunderstorm WarningABR30 min
May 26, 9:59 PM CDTSevere Thunderstorm WarningABR46 min
May 26, 10:43 PM CDTSevere Thunderstorm WarningABR62 min
Jun 10, 12:10 AM CDTSevere Thunderstorm WarningABR65 min
Jun 10, 12:49 AM CDTSevere Thunderstorm WarningABR26 min
Jun 10, 1:03 AM CDTSevere Thunderstorm WarningABR57 min
Jun 10, 1:13 AM CDTSevere Thunderstorm WarningABR62 min
Jun 10, 1:15 AM CDTSevere Thunderstorm WarningABR30 min
Jun 10, 1:44 AM CDTSevere Thunderstorm WarningABR31 min
Jun 25, 10:27 PM CDTSevere Thunderstorm WarningABR48 min
Jun 25, 11:22 PM CDTSevere Thunderstorm WarningABR20 min
Jul 21, 12:07 AM CDTSevere Thunderstorm WarningABR38 min
Jul 24, 10:27 PM CDTSevere Thunderstorm WarningABR25 min
Aug 22, 9:25 PM CDTSevere Thunderstorm WarningABR50 min
Sep 3, 4:18 PM CDTSevere Thunderstorm WarningABR42 min

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe 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.