Alert archive / Tennessee

Weather alerts in Anderson County, Tennessee

2,902 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Anderson County and its neighbors

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

Alerts
2,902
Warnings
898
Watches
445
Advisories
735
Busiest year
2011181 alerts
Average year
74over 39 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, of tornado reports in Anderson County fell inside a tornado warning, and 87% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200810100%0
200920100%0
201010100%0
20118363%0
20125180%0
201440100%0
202320100%0
202570100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008241825%786%21 min
2009393218%1694%30 min
2010121017%20%
2011473232%6100%31 min
2012281836%1070%16 min
2013141214%9100%18 min
2014221818%863%15 min
2015201715%250%15 min
2016171324%888%13 min
2017131115%367%18 min
2018181611%0
201911110%1155%22 min
2020151313%425%25 min
2021131115%580%24 min
2022221914%475%29 min
202350468%1182%17 min
2024271833%3100%9 min
2025211910%757%17 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20093233%1100%52 min
201010100%0
20113233%1100%34 min
201410100%0
201610100%0
2017330%3100%58 min
201810100%0
2019110%1100%50 min
2020220%0
20216433%0
2022440%3100%61 min
20238625%250%19 min
20244175%0
20256350%0

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 23, 8:45 PM EDTFlash Flood WarningMRX2 hr
Sep 5, 1:03 PM EDTSevere Thunderstorm WarningMRX57 min
Aug 20, 10:00 PM EDTSevere Thunderstorm WarningMRX15 min
Aug 17, 5:18 PM EDTFlash Flood WarningMRX3 hr
Aug 17, 4:33 PM EDTSevere Thunderstorm WarningMRX57 min
Aug 17, 4:07 PM EDTSevere Thunderstorm WarningMRX53 min
Aug 17, 3:50 PM EDTSevere Thunderstorm WarningMRX40 min
Aug 17, 3:26 PM EDTSevere Thunderstorm WarningMRX64 min
Aug 14, 1:49 PM EDTSevere Thunderstorm WarningMRX41 min
Jul 22, 10:10 AM EDTFlash Flood WarningMRX3 hr
Jul 17, 3:50 PM EDTFlash Flood WarningMRX97 min
Jul 12, 12:00 AM EDTFlash Flood WarningMRX3 hr

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.