Weather alerts in Polk County, Tennessee, 2020

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

Polk County and its neighbors

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

Alerts: 119
Warnings: 32
Watches: 18
Advisories: 27
Busiest month: April31 alerts
Busiest day: April 13, 202016 alerts

Over time

By month

Warning verification

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

3 of 5 tornado warnings covering Polk County in 2020 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 1 minutes after it went out.

Polk County, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	5	3	40%	1	100%	1 min
Severe thunderstorm warnings	13	11	15%	10	80%	13 min
Flash flood warnings	2	1	50%	0

Each office's whole area, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Morristown, TN: tornado warnings	13	5	62%	6	83%	6 min
NWS Morristown, TN: severe thunderstorm warnings	158	129	18%	243	81%	21 min
NWS Morristown, TN: flash flood warnings	22	18	18%	33	82%	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.

Issued	Product	Office	Lasted
Jan 1, 3:26 AM EST	Flood Watch	MRX	64 hr
Jan 10, 2:39 PM EST	Wind Advisory	MRX	34 hr
Jan 11, 1:20 PM EST	Mesoscale Discussion	SPC	85 min
Jan 11, 1:42 PM EST	Tornado Watch	SPC	7 hr
Jan 11, 3:49 PM EST	Severe Thunderstorm Warning	MRX	56 min
Jan 11, 4:13 PM EST	Severe Thunderstorm Warning	MRX	47 min
Jan 11, 4:16 PM EST	Mesoscale Discussion	SPC	89 min
Jan 11, 4:31 PM EST	Tornado Warning	MRX	29 min
Jan 11, 4:38 PM EST	Severe Thunderstorm Warning	MRX	52 min
Feb 4, 3:46 PM EST	Flash Flood Watch	MRX	47 hr
Feb 5, 5:18 PM EST	Areal Flood Warning	MRX	27 hr
Feb 6, 3:32 AM EST	Flash Flood Warning	MRX	4 hr
Feb 6, 7:30 AM EST	Areal Flood Warning	MRX	12 hr
Feb 6, 7:39 AM EST	River Flood Advisory	MRX	2 hr
Feb 6, 10:26 AM EST	River Flood Warning	MRX	13 hr
Feb 6, 7:09 PM EST	Areal Flood Warning	MRX	14 hr
Feb 6, 8:04 PM EST	Areal Flood Warning	MRX	15 hr
Feb 7, 2:57 PM EST	Winter Weather Advisory	MRX	25 hr
Feb 9, 1:24 AM EST	Freezing Fog Advisory	MRX	8 hr
Feb 9, 3:35 AM EST	Flood Watch	MRX	36 hr
Feb 10, 3:14 PM EST	Flash Flood Watch	MRX	24 hr
Feb 12, 3:03 AM EST	Flash Flood Watch	MRX	31 hr
Feb 12, 8:37 PM EST	Mesoscale Discussion	SPC	83 min
Feb 19, 11:44 AM EST	Winter Weather Advisory	MRX	34 hr
Mar 18, 3:59 AM EDT	Dense Fog Advisory	MRX	6 hr
Mar 23, 5:05 AM EDT	Special Weather Statement	MRX	40 min
Mar 23, 8:59 AM EDT	Areal Flood Advisory	MRX	3 hr
Mar 24, 4:31 AM EDT	Flash Flood Watch	MRX	23 hr
Mar 24, 9:50 AM EDT	Special Weather Statement	MRX	55 min
Mar 24, 8:05 PM EDT	Mesoscale Discussion	SPC	55 min
Mar 24, 8:44 PM EDT	Tornado Watch	SPC	3 hr
Mar 24, 10:45 PM EDT	Mesoscale Discussion	SPC	60 min
Apr 1, 9:06 PM EDT	Frost Advisory	MRX	12 hr
Apr 8, 10:52 PM EDT	Mesoscale Discussion	SPC	113 min
Apr 8, 11:16 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Apr 9, 2:00 AM EDT	Special Weather Statement	MRX	30 min
Apr 10, 3:32 PM EDT	Frost Advisory	MRX	18 hr
Apr 11, 9:32 PM EDT	Wind Advisory	MRX	42 hr
Apr 11, 9:41 PM EDT	Flash Flood Watch	MRX	32 hr
Apr 12, 8:41 PM EDT	Mesoscale Discussion	SPC	64 min
Apr 12, 8:57 PM EDT	Tornado Watch	SPC	6 hr
Apr 12, 9:14 PM EDT	Special Weather Statement	MRX	46 min
Apr 12, 9:37 PM EDT	Severe Thunderstorm Warning	MRX	53 min
Apr 12, 9:59 PM EDT	Tornado Warning	MRX	31 min
Apr 12, 11:16 PM EDT	Tornado Warning Emergency	MRX	29 min
Apr 12, 11:17 PM EDT	Mesoscale Discussion	SPC	88 min
Apr 12, 11:28 PM EDT	Tornado Warning Tornado observedConsiderable damage threat	MRX	32 min
Apr 12, 11:41 PM EDT	Severe Thunderstorm Warning	MRX	49 min
Apr 12, 11:56 PM EDT	Tornado Warning	MRX	34 min
Apr 12, 11:59 PM EDT	Areal Flood Advisory	MRX	3 hr
Apr 13, 12:19 AM EDT	Areal Flood Warning	MRX	3 hr
Apr 13, 12:22 AM EDT	Areal Flood Warning	MRX	3 hr
Apr 13, 12:31 AM EDT	Severe Thunderstorm Warning	MRX	44 min
Apr 13, 12:59 AM EDT	Flash Flood Warning	MRX	3 hr
Apr 13, 8:00 AM EDT	River Flood Advisory	MRX	3 hr
Apr 25, 3:32 PM EDT	Mesoscale Discussion	SPC	88 min
Apr 25, 4:48 PM EDT	Special Weather Statement	MRX	42 min
Apr 25, 5:18 PM EDT	Severe Thunderstorm Warning	MRX	42 min
Apr 25, 5:30 PM EDT	Severe Thunderstorm Warning	MRX	45 min
Apr 25, 6:11 PM EDT	Tornado Watch	SPC	4 hr
Apr 25, 6:16 PM EDT	Special Weather Statement	MRX	44 min
Apr 25, 6:38 PM EDT	Severe Thunderstorm Warning	MRX	41 min
Apr 29, 5:12 PM EDT	Special Weather Statement	MRX	48 min
May 4, 7:42 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
May 4, 9:16 PM EDT	Mesoscale Discussion	SPC	89 min
May 5, 12:08 AM EDT	Mesoscale Discussion	SPC	97 min
May 5, 12:09 AM EDT	Special Weather Statement	MRX	51 min
May 5, 3:22 PM EDT	Mesoscale Discussion	SPC	113 min
May 7, 3:51 AM EDT	Freeze Watch	MRX	24 hr
May 8, 3:56 AM EDT	Frost Advisory	MRX	30 hr
May 8, 3:56 AM EDT	Freeze Warning	MRX	30 hr
May 9, 3:26 AM EDT	Frost Advisory	MRX	31 hr
May 9, 3:26 AM EDT	Freeze Warning	MRX	31 hr
Jun 10, 6:23 PM EDT	Mesoscale Discussion	SPC	97 min
Jun 10, 6:55 PM EDT	Special Weather Statement	MRX	50 min
Jun 14, 3:36 PM EDT	Special Weather Statement	MRX	39 min
Jun 21, 5:51 PM EDT	Severe Thunderstorm Warning	MRX	54 min
Jun 22, 2:43 PM EDT	Special Weather Statement	MRX	47 min
Jun 28, 2:38 PM EDT	Special Weather Statement	FFC	37 min
Jun 30, 2:21 PM EDT	Special Weather Statement	MRX	39 min
Jun 30, 2:59 PM EDT	Special Weather Statement	MRX	46 min
Jul 8, 6:34 PM EDT	Special Weather Statement	MRX	41 min
Jul 8, 7:12 PM EDT	Areal Flood Advisory	MRX	2 hr
Jul 19, 5:22 PM EDT	Special Weather Statement	MRX	38 min
Jul 20, 12:57 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 21, 1:00 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 21, 4:27 PM EDT	Special Weather Statement	MRX	48 min
Jul 21, 4:32 PM EDT	Severe Thunderstorm Warning	MRX	43 min
Jul 23, 1:11 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 24, 4:00 PM EDT	Special Weather Statement	MRX	45 min
Jul 24, 4:40 PM EDT	Severe Thunderstorm Warning	MRX	50 min
Jul 24, 5:26 PM EDT	Severe Thunderstorm Warning	MRX	25 min
Jul 24, 6:06 PM EDT	Special Weather Statement	MRX	24 min
Jul 28, 1:46 PM EDT	Special Weather Statement	MRX	44 min
Jul 30, 12:21 AM EDT	Areal Flood Advisory	MRX	114 min
Jul 31, 1:21 PM EDT	Mesoscale Discussion	SPC	54 min
Aug 3, 10:32 PM EDT	Special Weather Statement	MRX	43 min
Aug 6, 5:12 PM EDT	Special Weather Statement	MRX	48 min
Aug 10, 2:17 PM EDT	Mesoscale Discussion	SPC	118 min
Aug 19, 3:44 PM EDT	Special Weather Statement	MRX	46 min
Aug 19, 3:45 PM EDT	Special Weather Statement	MRX	30 min
Aug 23, 8:51 AM EDT	Areal Flood Advisory	MRX	114 min
Sep 15, 3:37 PM EDT	Flash Flood Watch	MRX	47 hr
Oct 16, 3:12 AM EDT	Frost Advisory	MRX	31 hr
Oct 28, 3:52 AM EDT	Flash Flood Watch	MRX	30 hr
Oct 28, 10:47 AM EDT	High Wind Watch	MRX	5 hr
Oct 28, 10:47 AM EDT	Wind Advisory	MRX	28 hr
Oct 28, 2:58 PM EDT	Tropical Storm Warning	MRX	24 hr
Oct 30, 3:18 PM EDT	Freeze Watch	MRX	37 hr
Nov 1, 3:16 AM EST	Freeze Warning	MRX	30 hr
Nov 2, 2:39 PM EST	Frost Advisory	MRX	18 hr
Nov 2, 2:39 PM EST	Freeze Warning	MRX	18 hr
Nov 29, 3:55 PM EST	Winter Weather Advisory	MRX	44 hr
Dec 6, 2:33 AM EST	Freezing Fog Advisory	MRX	7 hr
Dec 13, 5:28 AM EST	Dense Fog Advisory	MRX	4 hr
Dec 21, 3:36 AM EST	Dense Fog Advisory	MRX	5 hr
Dec 23, 2:14 PM EST	Winter Weather Advisory	MRX	38 hr
Dec 23, 11:37 PM EST	Wind Advisory	MRX	10 hr
Dec 29, 1:41 AM EST	Dense Fog Advisory	MRX	6 hr

By product

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

Product	Alerts
Severe storms
Severe Thunderstorm Warning	13
Tornado Warning	5
Severe Thunderstorm Watch	2
Tornado Watch	4
Mesoscale Discussion	18
Special Weather Statement	24
Flooding
Areal Flood Warning	6
Flash Flood Warning	2
River Flood Warning	1
Flash Flood Watch	7
Flood Watch	2
Areal Flood Advisory	5
River Flood Advisory	2
Winter
Winter Weather Advisory	4
Cold
Freeze Warning	4
Freeze Watch	2
Frost Advisory	6
Wind and dust
High Wind Watch	1
Wind Advisory	4
Fog and smoke
Dense Fog Advisory	4
Freezing Fog Advisory	2
Tropical
Tropical Storm Warning	1

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2019 2021

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.