Alert archive / Michigan / Genesee County / Severe Thunderstorm Warnings

Severe Thunderstorm Warnings in Genesee County, Michigan, 2011

10 severe thunderstorm warnings in 2011. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Genesee County and its neighbors

Each county as a circle sized by its count in 2011. Tap one for its archive.

Severe Thunderstorm Warnings
10
Busiest month
June4 severe thunderstorm warnings
Busiest day
June 22, 20113 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 10 severe thunderstorm warnings covering Genesee County in 2011 had a qualifying storm report inside them; 8 of 15 hail, wind and damage reports fell inside a warning, on average 16 minutes after it went out.

Genesee County, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Severe thunderstorm warnings10820%1553%16 min

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Detroit, MI: severe thunderstorm warnings14510031%26780%28 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, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
May 13, 8:37 PM EDTSevere Thunderstorm WarningDTX52 min
May 31, 8:25 PM EDTSevere Thunderstorm WarningDTX50 min
Jun 21, 9:44 PM EDTSevere Thunderstorm WarningDTX76 min
Jun 22, 2:41 PM EDTSevere Thunderstorm WarningDTX59 min
Jun 22, 4:44 PM EDTSevere Thunderstorm WarningDTX46 min
Jul 2, 5:07 PM EDTSevere Thunderstorm WarningDTX53 min
Jul 11, 11:57 AM EDTSevere Thunderstorm WarningDTX63 min
Jul 18, 3:27 PM EDTSevere Thunderstorm WarningDTX63 min
Aug 20, 2:03 PM EDTSevere Thunderstorm WarningDTX25 min
Aug 20, 3:04 PM EDTSevere Thunderstorm WarningDTX71 min

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20102012

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.