Alert archive / Tennessee / Johnson County

Weather alerts in Johnson County, Tennessee, 2025

107 weather alerts in 2025, 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 2025. Tap one for its archive.

Alerts
107
Warnings
26
Watches
12
Advisories
42
Busiest month
March17 alerts
Busiest day
March 3, 20254 alerts

Over time

By month

Warning verification

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

Johnson County, 2025

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings7614%2100%13 min
Flash flood warnings5180%0

Each office's whole area, 2025

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Morristown, TN: tornado warnings28293%367%11 min
NWS Morristown, TN: severe thunderstorm warnings23118719%30084%22 min
NWS Morristown, TN: flash flood warnings663645%6685%70 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
Jan 4, 3:31 AM ESTWinter Weather AdvisoryMRX39 hr
Jan 5, 2:39 AM ESTWind AdvisoryMRX28 hr
Jan 6, 2:52 AM ESTWinter Weather AdvisoryMRX28 hr
Jan 8, 3:33 AM ESTWinter Storm WatchMRX32 hr
Jan 8, 7:43 AM ESTWinter Weather AdvisoryMRX5 hr
Jan 9, 11:46 AM ESTWinter Storm WarningMRX43 hr
Jan 18, 3:50 AM ESTWinter Storm WatchMRX11 hr
Jan 18, 2:34 PM ESTExtreme Cold WatchMRX13 hr
Jan 18, 2:58 PM ESTWinter Storm WarningMRX37 hr
Jan 19, 3:37 AM ESTExtreme Cold WarningMRX32 hr
Jan 20, 3:23 PM ESTCold Weather AdvisoryMRX43 hr
Feb 6, 5:10 PM ESTMesoscale DiscussionSPC2 hr
Feb 6, 10:15 PM ESTSevere Thunderstorm WarningMRX24 min
Feb 10, 2:03 PM ESTFlood WatchMRX61 hr
Feb 10, 2:03 PM ESTWinter Weather AdvisoryMRX22 hr
Feb 11, 12:26 PM ESTMesoscale DiscussionSPC5 hr
Feb 13, 2:50 PM ESTHigh Wind WatchMRX12 hr
Feb 14, 2:49 AM ESTHigh Wind WarningMRX57 hr
Feb 16, 11:55 AM ESTWind AdvisoryMRX4 hr
Feb 17, 3:23 PM ESTWinter Weather AdvisoryMRX3 days
Feb 18, 3:08 PM ESTCold Weather AdvisoryMRX49 hr
Feb 20, 3:18 AM ESTCold Weather AdvisoryMRX31 hr
Feb 28, 8:50 PM ESTRed Flag WarningMRX23 hr
Mar 3, 3:19 AM ESTHigh Wind WatchMRX10 hr
Mar 3, 1:30 PM ESTHigh Wind WarningMRX39 hr
Mar 3, 1:30 PM ESTWind AdvisoryMRX54 hr
Mar 3, 1:47 PM ESTRed Flag WarningMRX34 hr
Mar 5, 4:33 AM ESTWinter Weather AdvisoryMRX29 hr
Mar 12, 2:23 PM EDTHigh Wind WatchMRX24 hr
Mar 13, 2:37 PM EDTHigh Wind WarningMRX64 hr
Mar 14, 2:58 PM EDTRed Flag WarningMRX32 hr
Mar 15, 1:34 AM EDTWind AdvisoryMRX30 hr
Mar 18, 2:00 PM EDTWind AdvisoryMRX42 hr
Mar 18, 2:46 PM EDTRed Flag WarningMRX32 hr
Mar 22, 10:55 AM EDTRed Flag WarningMRX12 hr
Mar 22, 3:01 PM EDTRed Flag WarningMRX30 hr
Mar 26, 9:53 AM EDTRed Flag WarningMRX10 hr
Mar 31, 6:14 AM EDTSpecial Weather StatementMRX46 min
Mar 31, 6:34 AM EDTSevere Thunderstorm WarningMRX26 min
Apr 1, 12:52 PM EDTWind AdvisoryMRX43 hr
Apr 25, 9:14 PM EDTSpecial Weather StatementMRX31 min
May 2, 7:11 PM EDTSpecial Weather StatementMRX49 min
May 2, 7:35 PM EDTSevere Thunderstorm WarningMRX40 min
May 8, 3:30 PM EDTSevere Thunderstorm WatchSPC8 hr
May 8, 7:11 PM EDTMesoscale DiscussionSPC64 min
May 9, 4:56 AM EDTDense Fog AdvisoryMRX4 hr
May 16, 10:26 AM EDTMesoscale DiscussionSPC2 hr
May 16, 11:10 AM EDTSevere Thunderstorm WatchSPC6 hr
May 16, 12:59 PM EDTMesoscale DiscussionSPC2 hr
May 16, 9:37 PM EDTTornado WatchSPC6 hr
May 17, 2:29 AM EDTSevere Thunderstorm WarningMRX61 min
May 17, 3:09 AM EDTSpecial Weather StatementMRX51 min
May 17, 3:18 AM EDTMesoscale DiscussionSPC87 min
May 20, 6:14 PM EDTSpecial Weather StatementMRX46 min
May 31, 1:32 PM EDTMesoscale DiscussionSPC118 min
Jun 1, 4:22 PM EDTSpecial Weather StatementMRX38 min
Jun 17, 10:47 PM EDTSpecial Weather StatementMRX43 min
Jun 20, 3:12 AM EDTDense Fog AdvisoryMRX7 hr
Jun 24, 6:21 PM EDTSpecial Weather StatementMRX39 min
Jun 24, 6:39 PM EDTAreal Flood AdvisoryMRX3 hr
Jun 25, 11:50 AM EDTMesoscale DiscussionSPC115 min
Jun 26, 12:48 PM EDTMesoscale DiscussionSPC117 min
Jun 26, 2:08 PM EDTAreal Flood AdvisoryMRX2 hr
Jun 27, 10:38 PM EDTFlash Flood WarningMRX3 hr
Jun 29, 1:07 PM EDTMesoscale DiscussionSPC2 hr
Jun 30, 3:14 PM EDTAreal Flood AdvisoryMRX17 min
Jun 30, 3:31 PM EDTFlash Flood WarningMRX3 hr
Jul 1, 1:00 PM EDTMesoscale DiscussionSPC2 hr
Jul 1, 7:29 PM EDTAreal Flood AdvisoryMRX3 hr
Jul 9, 11:30 AM EDTMesoscale DiscussionSPC90 min
Jul 9, 4:58 PM EDTAreal Flood AdvisoryMRX2 hr
Jul 12, 4:51 PM EDTFlash Flood WarningMRX92 min
Jul 17, 7:00 AM EDTFlood WatchMRX41 hr
Jul 21, 1:14 PM EDTAreal Flood AdvisoryMRX5 hr
Jul 22, 5:21 AM EDTDense Fog AdvisoryMRX4 hr
Jul 27, 2:00 AM EDTSpecial Weather StatementMRX30 min
Jul 27, 1:19 PM EDTSpecial Weather StatementMRX41 min
Jul 27, 2:05 PM EDTFlash Flood WarningMRX2 hr
Jul 28, 3:57 PM EDTSevere Thunderstorm WarningMRX23 min
Jul 30, 5:07 PM EDTAreal Flood AdvisoryMRX24 min
Jul 30, 5:52 PM EDTAreal Flood AdvisoryMRX4 hr
Aug 13, 3:43 AM EDTFlood WatchMRX11 hr
Aug 13, 9:50 AM EDTFlash Flood WarningMRX4 hr
Aug 13, 1:21 PM EDTAreal Flood WarningMRX106 min
Aug 17, 4:28 PM EDTSpecial Weather StatementMRX47 min
Aug 17, 5:09 PM EDTSpecial Weather StatementMRX36 min
Sep 4, 12:39 PM EDTSpecial Weather StatementMRX51 min
Sep 6, 5:25 AM EDTSpecial Weather StatementMRX50 min
Sep 27, 4:04 PM EDTAreal Flood AdvisoryMRX2 hr
Oct 18, 1:16 AM EDTWind AdvisoryMRX37 hr
Oct 28, 1:34 AM EDTWind AdvisoryMRX44 hr
Nov 4, 4:42 AM ESTDense Fog AdvisoryMRX5 hr
Nov 8, 6:23 AM ESTDense Fog AdvisoryMRX5 hr
Nov 9, 1:01 AM ESTWinter Weather AdvisoryMRX51 hr
Nov 15, 10:41 AM ESTWind AdvisoryMRX20 hr
Nov 20, 6:15 AM ESTDense Fog AdvisoryMRX5 hr
Nov 24, 12:26 PM ESTWind AdvisoryMRX28 hr
Dec 4, 12:14 PM ESTWinter Weather AdvisoryMRX20 hr
Dec 7, 12:43 PM ESTWinter Weather AdvisoryMRX30 hr
Dec 10, 12:35 AM ESTWind AdvisoryMRX24 hr
Dec 10, 12:39 AM ESTWinter Weather AdvisoryMRX33 hr
Dec 13, 12:24 PM ESTCold Weather AdvisoryMRX46 hr
Dec 17, 7:52 PM ESTWind AdvisoryMRX31 hr
Dec 19, 12:45 AM ESTSevere Thunderstorm WarningMRX45 min
Dec 19, 12:49 AM ESTSevere Thunderstorm WarningMRX41 min
Dec 19, 1:31 AM ESTSpecial Weather StatementMRX29 min
Dec 27, 11:43 PM ESTWind AdvisoryMRX43 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 archive20242026

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.