Alert archive / Michigan / Delta County / Severe Thunderstorm Warnings

Severe Thunderstorm Warnings in Delta County, Michigan, 2015

14 severe thunderstorm warnings in 2015. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Delta County and its neighbors

Each county as a circle sized by its count in 2015. Tap one for its archive.

Severe Thunderstorm Warnings
14
Busiest month
August7 severe thunderstorm warnings
Busiest day
August 2, 20153 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.

6 of 14 severe thunderstorm warnings covering Delta County in 2015 had a qualifying storm report inside them; 6 of 6 hail, wind and damage reports fell inside a warning, on average 12 minutes after it went out.

Delta County, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Severe thunderstorm warnings14657%6100%12 min

Each office's whole area, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Marquette, MI: severe thunderstorm warnings391367%3465%10 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 3, 7:55 PM EDTSevere Thunderstorm WarningMQT50 min
May 3, 8:45 PM EDTSevere Thunderstorm WarningMQT36 min
Jun 22, 8:22 PM EDTSevere Thunderstorm WarningMQT23 min
Jun 24, 3:10 PM EDTSevere Thunderstorm WarningMQT31 min
Jun 24, 3:49 PM EDTSevere Thunderstorm WarningMQT27 min
Jul 25, 1:14 AM EDTSevere Thunderstorm WarningMQT47 min
Aug 2, 7:57 AM EDTSevere Thunderstorm WarningMQT48 min
Aug 2, 8:13 AM EDTSevere Thunderstorm WarningMQT47 min
Aug 2, 8:35 AM EDTSevere Thunderstorm WarningMQT32 min
Aug 14, 12:43 PM EDTSevere Thunderstorm WarningMQT32 min
Aug 14, 1:33 PM EDTSevere Thunderstorm WarningMQT42 min
Aug 14, 2:13 PM EDTSevere Thunderstorm WarningMQT32 min
Aug 17, 4:43 AM EDTSevere Thunderstorm WarningMQT23 min
Sep 2, 11:57 AM EDTSevere Thunderstorm WarningMQT63 min

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20142016

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.