Alert archive / Illinois / Adams County / Severe Thunderstorm Warnings

Severe Thunderstorm Warnings in Adams County, Illinois, 2012

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

Adams County and its neighbors

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

Severe Thunderstorm Warnings
8
Busiest month
April2 severe thunderstorm warnings
Busiest day
April 26, 20122 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.

3 of 8 severe thunderstorm warnings covering Adams County in 2012 had a qualifying storm report inside them; 6 of 11 hail, wind and damage reports fell inside a warning, on average 33 minutes after it went out.

Adams County, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Severe thunderstorm warnings8363%1155%33 min

Each office's whole area, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS St. Louis, MO: severe thunderstorm warnings34616353%60181%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
Apr 25, 8:21 PM CDTSevere Thunderstorm WarningLSX54 min
Apr 25, 9:13 PM CDTSevere Thunderstorm WarningLSX62 min
May 4, 4:03 AM CDTSevere Thunderstorm WarningLSX42 min
Jun 24, 10:24 AM CDTSevere Thunderstorm WarningLSX21 min
Jul 2, 7:00 PM CDTSevere Thunderstorm WarningLSX45 min
Sep 5, 6:36 AM CDTSevere Thunderstorm WarningLSX30 min
Oct 22, 6:20 AM CDTSevere Thunderstorm WarningLSX55 min
Oct 22, 6:56 AM CDTSevere Thunderstorm WarningLSX49 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.