Alert archive / Tennessee / Union County

Weather alerts in Union County, Tennessee, 2020

98 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Union County and its neighbors

Each county as a circle sized by its count in 2020. Tap one for its archive.

Alerts
98
Warnings
22
Watches
12
Advisories
32
Busiest month
April16 alerts
Busiest day
February 6, 20205 alerts

Over time

By month

Warning verification

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

Union County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings13128%3100%28 min
Flash flood warnings00

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Morristown, TN: tornado warnings13562%683%6 min
NWS Morristown, TN: severe thunderstorm warnings15812918%24381%21 min
NWS Morristown, TN: flash flood warnings221818%3382%42 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 1, 3:26 AM ESTFlood WatchMRX64 hr
Jan 3, 4:57 AM ESTAreal Flood AdvisoryMRX4 hr
Jan 10, 2:39 PM ESTWind AdvisoryMRX34 hr
Jan 11, 4:16 PM ESTMesoscale DiscussionSPC89 min
Jan 11, 4:56 PM ESTSevere Thunderstorm WarningMRX49 min
Jan 11, 5:37 PM ESTSevere Thunderstorm WarningMRX53 min
Feb 4, 3:46 PM ESTFlash Flood WatchMRX47 hr
Feb 5, 10:20 PM ESTAreal Flood AdvisoryMRX5 hr
Feb 5, 10:46 PM ESTSpecial Weather StatementMRX44 min
Feb 6, 3:15 AM ESTAreal Flood WarningMRX6 hr
Feb 6, 5:08 AM ESTRiver Flood WarningMRX63 hr
Feb 6, 9:03 AM ESTAreal Flood WarningMRX12 hr
Feb 6, 8:41 PM ESTAreal Flood WarningMRX15 hr
Feb 9, 3:35 AM ESTFlood WatchMRX36 hr
Feb 10, 3:14 PM ESTFlash Flood WatchMRX24 hr
Feb 12, 3:03 AM ESTFlash Flood WatchMRX31 hr
Feb 12, 9:12 PM ESTSevere Thunderstorm WarningMRX48 min
Feb 12, 9:22 PM ESTSevere Thunderstorm WarningMRX53 min
Mar 3, 3:47 AM ESTSpecial Weather StatementMRX58 min
Mar 3, 4:28 AM ESTSpecial Weather StatementMRX47 min
Mar 3, 5:42 AM ESTAreal Flood AdvisoryMRX3 hr
Mar 18, 3:59 AM EDTDense Fog AdvisoryMRX6 hr
Mar 25, 9:29 AM EDTRiver Flood AdvisoryMRX12 hr
Mar 25, 10:51 PM EDTRiver Flood AdvisoryMRX12 hr
Mar 26, 10:52 AM EDTRiver Flood AdvisoryMRX12 hr
Mar 29, 4:23 AM EDTSevere Thunderstorm WarningMRX37 min
Apr 8, 11:16 PM EDTSevere Thunderstorm WatchSPC6 hr
Apr 9, 1:55 AM EDTSpecial Weather StatementMRX50 min
Apr 9, 3:13 PM EDTFreeze WatchMRX12 hr
Apr 10, 3:35 AM EDTFreeze WarningMRX30 hr
Apr 11, 9:32 PM EDTWind AdvisoryMRX42 hr
Apr 11, 9:41 PM EDTFlash Flood WatchMRX32 hr
Apr 12, 9:44 AM EDTRiver Flood WarningMRX60 hr
Apr 13, 1:58 AM EDTAreal Flood AdvisoryMRX3 hr
Apr 14, 3:40 PM EDTFreeze WarningMRX18 hr
Apr 15, 3:24 PM EDTFrost AdvisoryMRX18 hr
Apr 16, 3:34 PM EDTFrost AdvisoryMRX18 hr
Apr 25, 6:11 PM EDTTornado WatchSPC4 hr
Apr 25, 6:40 PM EDTSpecial Weather StatementMRX50 min
Apr 25, 7:24 PM EDTSpecial Weather StatementMRX36 min
Apr 27, 4:11 AM EDTDense Fog AdvisoryMRX6 hr
Apr 29, 4:57 PM EDTSpecial Weather StatementMRX48 min
May 3, 4:08 PM EDTMesoscale DiscussionSPC67 min
May 3, 6:52 PM EDTSevere Thunderstorm WatchSPC3 hr
May 8, 3:56 AM EDTFrost AdvisoryMRX30 hr
May 9, 3:26 AM EDTFrost AdvisoryMRX31 hr
May 23, 2:58 AM EDTDense Fog AdvisoryMRX7 hr
May 24, 7:28 PM EDTSpecial Weather StatementMRX32 min
Jun 10, 4:54 PM EDTSpecial Weather StatementMRX51 min
Jun 10, 6:23 PM EDTMesoscale DiscussionSPC97 min
Jun 10, 6:45 PM EDTSpecial Weather StatementMRX45 min
Jun 21, 1:00 PM EDTMesoscale DiscussionSPC2 hr
Jun 21, 3:43 PM EDTSevere Thunderstorm WarningMRX47 min
Jun 21, 3:52 PM EDTSpecial Weather StatementMRX23 min
Jun 22, 10:37 PM EDTSpecial Weather StatementMRX53 min
Jun 28, 12:49 PM EDTMesoscale DiscussionSPC2 hr
Jun 29, 2:58 AM EDTSpecial Weather StatementMRX47 min
Jun 29, 3:49 AM EDTSpecial Weather StatementMRX41 min
Jun 29, 4:29 AM EDTAreal Flood AdvisoryMRX4 hr
Jun 29, 5:07 PM EDTAreal Flood AdvisoryMRX3 hr
Jul 17, 1:47 PM EDTMesoscale DiscussionSPC118 min
Jul 20, 12:57 PM EDTMesoscale DiscussionSPC2 hr
Jul 22, 6:47 PM EDTSpecial Weather StatementMRX43 min
Jul 23, 1:11 PM EDTMesoscale DiscussionSPC2 hr
Jul 24, 3:49 PM EDTSevere Thunderstorm WarningMRX56 min
Jul 24, 4:15 PM EDTSevere Thunderstorm WarningMRX45 min
Jul 24, 4:34 PM EDTSevere Thunderstorm WarningMRX56 min
Jul 25, 1:25 PM EDTSevere Thunderstorm WarningMRX35 min
Jul 31, 5:52 AM EDTAreal Flood AdvisoryMRX3 hr
Jul 31, 1:21 PM EDTMesoscale DiscussionSPC54 min
Jul 31, 5:10 PM EDTSevere Thunderstorm WarningMRX50 min
Jul 31, 5:24 PM EDTSevere Thunderstorm WarningMRX36 min
Jul 31, 5:55 PM EDTSevere Thunderstorm WarningMRX35 min
Aug 5, 7:34 PM EDTAreal Flood AdvisoryMRX3 hr
Aug 5, 7:56 PM EDTSpecial Weather StatementMRX34 min
Aug 6, 7:45 PM EDTSpecial Weather StatementMRX45 min
Aug 16, 4:41 AM EDTDense Fog AdvisoryMRX5 hr
Aug 20, 5:43 PM EDTSpecial Weather StatementMRX47 min
Aug 26, 4:59 AM EDTDense Fog AdvisoryMRX5 hr
Aug 29, 6:30 PM EDTSpecial Weather StatementMRX45 min
Sep 3, 1:04 PM EDTSpecial Weather StatementMRX41 min
Sep 3, 1:42 PM EDTSpecial Weather StatementMRX48 min
Sep 3, 6:13 PM EDTSpecial Weather StatementMRX47 min
Sep 13, 4:17 PM EDTSpecial Weather StatementMRX43 min
Sep 27, 3:43 AM EDTDense Fog AdvisoryMRX6 hr
Oct 16, 3:12 AM EDTFrost AdvisoryMRX31 hr
Oct 28, 3:52 AM EDTFlash Flood WatchMRX30 hr
Oct 29, 6:00 AM EDTAreal Flood AdvisoryMRX3 hr
Oct 30, 3:18 PM EDTFrost AdvisoryMRX18 hr
Oct 30, 3:18 PM EDTFreeze WatchMRX37 hr
Nov 1, 3:16 AM ESTFreeze WarningMRX30 hr
Nov 2, 2:39 PM ESTFreeze WarningMRX18 hr
Nov 14, 4:04 AM ESTWind AdvisoryMRX39 hr
Dec 6, 2:33 AM ESTFreezing Fog AdvisoryMRX7 hr
Dec 13, 5:28 AM ESTDense Fog AdvisoryMRX4 hr
Dec 21, 3:36 AM ESTDense Fog AdvisoryMRX5 hr
Dec 23, 2:14 PM ESTWinter Weather AdvisoryMRX38 hr
Dec 23, 11:37 PM ESTWind AdvisoryMRX10 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 archive20192021

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.