Alert archive / Alabama

Weather alerts in Shelby County, Alabama

4,681 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Shelby County and its neighbors

Each county as a circle sized by its count since 1986. Tap one for its archive.

Alerts
4,681
Warnings
1,417
Watches
723
Advisories
1,163
Busiest year
2009305 alerts
Average year
114over 41 years on file

Over time

By year

Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.

By month of the year

Warning verification

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

From 2008 to 2025, 74% of tornado reports in Shelby County fell inside a tornado warning issued on average 23 minutes before, and 49% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008100100%0
200911736%1369%30 min
20104175%2100%3 min
2011171324%12100%26 min
2012110%0
2016110%10%
201720100%10%
2019330%989%4 min
202020100%30%
20218450%7100%34 min
20225260%540%29 min
2024020%
20253233%3100%25 min
Share of tornado reports inside a tornado warning, by year.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008502746%3664%26 min
2009503334%4367%33 min
2010302227%3177%20 min
2011464111%7175%30 min
2012312326%3979%23 min
20138450%1020%35 min
20147443%729%18 min
2015181139%3275%22 min
2016550%1974%31 min
2017151313%2080%31 min
20187529%1663%35 min
2019440%3628%22 min
2020181611%3650%18 min
202114750%1331%12 min
2022161225%2654%23 min
2023312229%3174%20 min
2024121017%2592%20 min
2025181611%3586%32 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20082150%250%16 min
2009161131%1191%56 min
20107529%250%40 min
20118713%4100%52 min
2012660%15100%33 min
2013220%3100%13 min
2014440%9100%100 min
20155420%3100%81 min
20174325%1100%8 min
201810100%0
2019110%2100%43 min
20208713%14100%118 min
202114843%4591%169 min
202211827%1090%131 min
2023440%4100%75 min
2024330%2100%61 min
20257614%475%30 min

Years from 2008, the first full year of storm-based warnings. The year still running is on its own page.

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.

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The latest warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Sep 19, 5:12 PM CDTSevere Thunderstorm WarningBMX32 min
Sep 19, 3:53 PM CDTSevere Thunderstorm WarningBMX28 min
Aug 26, 4:50 PM CDTSevere Thunderstorm WarningBMX23 min
Aug 22, 9:48 PM CDTSevere Thunderstorm WarningBMX26 min
Aug 16, 10:16 AM CDTExtreme Heat WarningBMX35 hr
Aug 9, 4:05 PM CDTFlash Flood WarningBMX3 hr
Jul 27, 6:37 AM CDTSevere Thunderstorm WarningBMX53 min
Jul 9, 4:18 PM CDTSevere Thunderstorm WarningBMX22 min
Jul 9, 4:04 PM CDTSevere Thunderstorm WarningBMX30 min
Jul 3, 6:30 PM CDTSevere Thunderstorm WarningBMX26 min
Jul 1, 6:27 PM CDTSevere Thunderstorm WarningBMX35 min
Jul 1, 6:08 PM CDTSevere Thunderstorm WarningBMX52 min

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive

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.