Alert archive / Tennessee / Johnson County

Weather alerts in Johnson County, Tennessee, 2026

107 weather alerts in 2026, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Johnson County and its neighbors

Each county as a circle sized by its count in 2026. Tap one for its archive.

Alerts
107
Warnings
18
Watches
16
Advisories
36
Busiest month
August33 alerts
Busiest day
August 17, 202612 alerts

Over time

By month

Warning verification

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

0 of 1 tornado warnings covering Johnson County in 2026 had a tornado report inside them.

Johnson County, 2026

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings10100%0
Severe thunderstorm warnings10910%250%5 min
Flash flood warnings2150%0

Each office's whole area, 2026

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Morristown, TN: tornado warnings10190%333%3 min
NWS Morristown, TN: severe thunderstorm warnings18214620%22689%22 min
NWS Morristown, TN: flash flood warnings815532%12884%70 min

An office's figures cover every county it serves, including across state lines.

The year is still running; reports filed late and damage surveys can still change these figures.

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
Jan 10, 1:22 PM ESTWind AdvisoryMRX30 hr
Jan 13, 11:29 AM ESTWinter Weather AdvisoryMRX48 hr
Jan 21, 12:27 PM ESTWinter Storm WatchMRX45 hr
Jan 23, 9:54 AM ESTWinter Storm WarningMRX49 hr
Jan 23, 9:54 AM ESTWinter Weather AdvisoryMRX47 hr
Jan 24, 6:45 PM ESTMesoscale DiscussionSPC5 hr
Jan 24, 11:49 PM ESTCold Weather AdvisoryMRX34 hr
Jan 25, 12:01 PM ESTCold Weather AdvisoryMRX48 hr
Jan 25, 12:01 PM ESTExtreme Cold WatchMRX14 hr
Jan 29, 2:50 AM ESTWinter Storm WatchMRX10 hr
Jan 29, 12:50 PM ESTWinter Storm WarningMRX57 hr
Jan 29, 1:00 PM ESTExtreme Cold WatchMRX23 hr
Jan 30, 12:20 PM ESTExtreme Cold WarningMRX48 hr
Feb 2, 12:39 AM ESTCold Weather AdvisoryMRX8 hr
Feb 4, 4:01 AM ESTDense Fog AdvisoryMRX8 hr
Feb 5, 12:30 PM ESTWind AdvisoryMRX55 hr
Feb 5, 12:30 PM ESTWinter Weather AdvisoryMRX43 hr
Feb 6, 12:34 PM ESTCold Weather AdvisoryMRX21 hr
Feb 14, 12:06 PM ESTWind AdvisoryMRX26 hr
Feb 19, 2:29 AM ESTWind AdvisoryMRX35 hr
Feb 21, 1:31 PM ESTWinter Weather AdvisoryMRX58 hr
Mar 9, 3:05 AM EDTDense Fog AdvisoryMRX7 hr
Mar 14, 2:07 AM EDTHigh Wind WatchMRX12 hr
Mar 14, 1:44 PM EDTHigh Wind WarningMRX42 hr
Mar 16, 12:41 AM EDTSevere Thunderstorm WatchSPC6 hr
Mar 16, 12:51 AM EDTWinter Weather AdvisoryMRX38 hr
Mar 16, 4:21 AM EDTMesoscale DiscussionSPC114 min
Apr 26, 12:52 AM EDTDense Fog AdvisoryMRX9 hr
Apr 27, 1:20 PM EDTWind AdvisoryMRX17 hr
Apr 29, 2:45 PM EDTMesoscale DiscussionSPC2 hr
May 2, 12:42 PM EDTFreeze WarningMRX20 hr
May 24, 12:57 PM EDTFlood WatchMRX13 hr
Jun 7, 2:09 PM EDTFlood WatchMRX31 hr
Jun 12, 2:36 PM EDTMesoscale DiscussionSPC24 min
Jun 18, 11:39 AM EDTSpecial Weather StatementMRX66 min
Jun 18, 1:43 PM EDTMesoscale DiscussionSPC62 min
Jun 18, 2:38 PM EDTFlood WatchMRX11 hr
Jun 18, 6:51 PM EDTAreal Flood AdvisoryMRX3 hr
Jun 22, 1:25 PM EDTMesoscale DiscussionSPC2 hr
Jun 27, 9:44 AM EDTFlood WatchMRX28 hr
Jun 27, 2:43 PM EDTSpecial Weather StatementMRX47 min
Jun 29, 1:34 PM EDTHeat AdvisoryMRX5 days
Jul 4, 1:38 PM EDTSpecial Weather StatementMRX52 min
Jul 4, 1:49 PM EDTSpecial Weather StatementMRX26 min
Jul 4, 10:35 PM EDTSevere Thunderstorm WarningMRX55 min
Jul 4, 11:02 PM EDTAreal Flood AdvisoryMRX3 hr
Jul 4, 11:05 PM EDTSevere Thunderstorm WarningMRX55 min
Jul 4, 11:07 PM EDTSevere Thunderstorm WarningMRX53 min
Jul 6, 5:03 PM EDTAreal Flood AdvisoryMRX117 min
Jul 9, 11:44 AM EDTFlood WatchMRX4 days
Jul 11, 8:38 AM EDTSpecial Weather StatementMRX37 min
Jul 18, 1:56 PM EDTMesoscale DiscussionSPC64 min
Jul 19, 3:11 PM EDTMesoscale DiscussionSPC2 hr
Jul 20, 1:20 PM EDTMesoscale DiscussionSPC115 min
Jul 21, 1:45 PM EDTFlood WatchMRX54 hr
Jul 28, 12:33 PM EDTMesoscale DiscussionSPC117 min
Jul 28, 1:14 PM EDTSevere Thunderstorm WatchSPC8 hr
Jul 28, 3:39 PM EDTMesoscale DiscussionSPC2 hr
Jul 28, 4:16 PM EDTTornado WarningMRX44 min
Jul 28, 4:30 PM EDTSevere Thunderstorm WarningMRX45 min
Jul 28, 4:55 PM EDTSevere Thunderstorm WarningMRX20 min
Aug 2, 1:09 PM EDTMesoscale DiscussionSPC2 hr
Aug 2, 10:56 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 4, 4:44 PM EDTAreal Flood AdvisoryMRX113 min
Aug 11, 2:04 PM EDTMesoscale DiscussionSPC116 min
Aug 11, 3:40 PM EDTSpecial Weather StatementMRX50 min
Aug 11, 4:07 PM EDTSevere Thunderstorm WarningMRX38 min
Aug 11, 4:17 PM EDTAreal Flood AdvisoryMRX118 min
Aug 11, 4:39 PM EDTAreal Flood AdvisoryMRX2 hr
Aug 11, 4:42 PM EDTMesoscale DiscussionSPC2 hr
Aug 11, 5:53 PM EDTMesoscale DiscussionSPC2 hr
Aug 11, 7:06 PM EDTSevere Thunderstorm WatchSPC4 hr
Aug 11, 7:50 PM EDTSevere Thunderstorm WarningMRX55 min
Aug 11, 8:24 PM EDTSevere Thunderstorm WarningMRX47 min
Aug 12, 2:38 AM EDTFlood WatchMRX29 hr
Aug 12, 11:41 PM EDTSpecial Weather StatementMRX49 min
Aug 14, 6:57 PM EDTSpecial Weather StatementMRX48 min
Aug 14, 7:07 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 14, 8:03 PM EDTFlash Flood WarningMRX3 hr
Aug 15, 1:25 PM EDTMesoscale DiscussionSPC3 hr
Aug 17, 1:49 PM EDTMesoscale DiscussionSPC116 min
Aug 17, 2:35 PM EDTSevere Thunderstorm WatchSPC7 hr
Aug 17, 3:26 PM EDTSevere Thunderstorm WarningMRX49 min
Aug 17, 3:48 PM EDTSpecial Weather StatementMRX42 min
Aug 17, 4:21 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 17, 4:31 PM EDTSpecial Weather StatementMRX44 min
Aug 17, 5:12 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 17, 5:32 PM EDTFlash Flood WarningMRX3 hr
Aug 17, 5:36 PM EDTSpecial Weather StatementMRX39 min
Aug 17, 5:49 PM EDTMesoscale DiscussionSPC116 min
Aug 17, 5:56 PM EDTSevere Thunderstorm WarningMRX34 min
Aug 17, 7:38 PM EDTSpecial Weather StatementMRX52 min
Aug 17, 8:21 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 17, 8:21 PM EDTAreal Flood AdvisoryMRX2 hr
Sep 5, 10:40 AM EDTMesoscale DiscussionSPC95 min
Sep 5, 11:56 AM EDTSpecial Weather StatementMRX49 min
Sep 6, 7:26 AM EDTSpecial Weather StatementMRX64 min
Sep 6, 8:00 AM EDTAreal Flood AdvisoryMRX2 hr
Sep 6, 12:13 PM EDTSpecial Weather StatementMRX62 min
Sep 6, 12:36 PM EDTAreal Flood AdvisoryMRX3 hr
Sep 18, 4:49 PM EDTAreal Flood AdvisoryMRX116 min
Sep 21, 6:34 PM EDTSpecial Weather StatementMRX26 min
Sep 21, 6:55 PM EDTSpecial Weather StatementMRX35 min
Sep 21, 7:08 PM EDTAreal Flood AdvisoryMRX2 hr
Sep 21, 7:11 PM EDTAreal Flood AdvisoryMRX2 hr
Sep 21, 7:17 PM EDTSpecial Weather StatementMRX43 min
Sep 21, 7:43 PM EDTAreal Flood AdvisoryMRX2 hr

By product

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

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive2025

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.