Alert archive / Tennessee / Tornado Watches in 2025

Tornado Watch 308

May 20, 20254 states

The Storm Prediction Center issued this tornado watch at May 20, 2025, 7:27 PM EDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 20, 2025, 7:27 PM EDT (23:27 UTC)
Expired: May 21, 2025, 1:52 AM EDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 60 kt

All 67 counties

Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Lumpkin County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Union County, GA, Walker County, GA, Whitfield County, GA, Bell County, KY, Breathitt County, KY, Clay County, KY, Estill County, KY, Harlan County, KY, Jackson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Cherokee County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Claiborne County, TN, Grainger County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Union County, TN

The radar

The Knoxville radar (KMRX), 62 km from the middle of the area, began a volume at 23:28 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 60%
One or more EF2 to EF5 tornadoes: 40%
Ten or more severe wind reports: 70%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 40%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

45 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 20, 8:25 PM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Hamilton, Meigs, Rhea, Sequatchie	50 min
May 20, 8:32 PM EDT	Tornado Warning	MRX	Bledsoe, Rhea	43 min
May 20, 8:43 PM EDT	Severe Thunderstorm Warning	JKL	Estill, Jackson, Rockcastle	62 min
May 20, 8:46 PM EDT	Tornado Warning	MRX	Morgan, Rhea, Roane	59 min
May 20, 8:47 PM EDT	Severe Thunderstorm Warning	FFC	Catoosa, Dade, Walker	43 min
May 20, 8:48 PM EDT	Severe Thunderstorm Warning	JKL	Jackson, Laurel, Pulaski, Rockcastle	57 min
May 20, 9:02 PM EDT	Tornado Warning	MRX	Bledsoe	43 min
May 20, 9:06 PM EDT	Severe Thunderstorm Warning	JKL	Laurel, McCreary, Pulaski, Wayne, Whitley	54 min
May 20, 9:09 PM EDT	Tornado Warning	MRX	McMinn, Meigs, Rhea	33 min
May 20, 9:13 PM EDT	Tornado Warning	FFC	Dade, Walker	36 min
May 20, 9:14 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Morgan, Roane, Scott	61 min
May 20, 9:21 PM EDT	Severe Thunderstorm Warning	JKL	Bell, Knox, McCreary, Wayne, Whitley	54 min
May 20, 9:25 PM EDT	Severe Thunderstorm Warning	JKL	Clay, Jackson, Laurel, Owsley, Pulaski, Rockcastle	50 min
May 20, 9:25 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon, Morgan, Roane	65 min
May 20, 9:30 PM EDT	Severe Thunderstorm Warning	FFC	Catoosa, Dade, Walker, Whitfield	45 min
May 20, 9:34 PM EDT	Severe Thunderstorm Warning	JKL	Breathitt, Estill, Jackson, Lee, Magoffin, Menifee and 4 more	56 min
May 20, 9:41 PM EDT	Severe Thunderstorm Warning	MRX	Loudon, McMinn, Meigs, Monroe	49 min
May 20, 9:47 PM EDT	Severe Thunderstorm Warning	JKL	Bell, Clay, Knox, Laurel, Whitley	28 min
May 20, 9:57 PM EDT	Tornado Warning	FFC	Catoosa, Murray, Walker, Whitfield	48 min
May 20, 9:59 PM EDT	Tornado Warning	MRX	Anderson, Knox, Sevier	46 min
May 20, 10:00 PM EDT	Severe Thunderstorm Warning	JKL	Bell, Breathitt, Clay, Harlan, Knott, Knox and 5 more	45 min
May 20, 10:06 PM EDT	Tornado Warning	FFC	Chattooga, Dade, Walker	39 min
May 20, 10:13 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Claiborne, Grainger, Knox, Union	49 min
May 20, 10:20 PM EDT	Severe Thunderstorm Warning	JKL	Breathitt, Floyd, Johnson, Knott, Magoffin, Martin and 4 more	55 min
May 20, 10:28 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Cocke, Grainger, Hamblen, Jefferson, Knox and 1 more	62 min
May 20, 10:31 PM EDT	Tornado Warning	FFC	Gilmer, Murray, Whitfield	20 min
May 20, 10:32 PM EDT	Severe Thunderstorm Warning	JKL	Bell, Harlan, Leslie, Letcher, Perry	43 min
May 20, 10:37 PM EDT	Tornado Warning	FFC	Chattooga, Floyd, Gordon, Walker, Whitfield	26 min
May 20, 10:37 PM EDT	Tornado Warning	FFC	Chattooga, Floyd, Gordon, Walker, Whitfield	42 min
May 20, 10:40 PM EDT	Tornado Warning	FFC	Chattooga, Walker	50 min
May 20, 10:50 PM EDT	Severe Thunderstorm Warning	FFC	Gilmer, Murray	24 min
May 20, 11:04 PM EDT	Tornado Warning	FFC	Chattooga, Floyd	41 min
May 20, 11:13 PM EDT	Severe Thunderstorm Warning	FFC	Bartow, Chattooga, Floyd, Gordon, Murray	47 min
May 20, 11:13 PM EDT	Severe Thunderstorm Warning	JKL	Harlan, Letcher, Pike	47 min
May 20, 11:15 PM EDT	Tornado Warning	FFC	Chattooga, Floyd, Gordon	45 min
May 20, 11:39 PM EDT	Tornado Warning	FFC	Gordon	36 min
May 20, 11:49 PM EDT	Severe Thunderstorm Warning	FFC	Bartow, Cherokee, Cobb, Floyd, Gordon, Paulding and 2 more	41 min
May 20, 11:54 PM EDT	Tornado Warning	FFC	Bartow, Cherokee, Gordon, Pickens	21 min
May 21, 12:19 AM EDT	Severe Thunderstorm Warning	FFC	Cherokee, Cobb, Dawson, DeKalb, Forsyth, Fulton and 4 more	41 min
May 21, 12:25 AM EDT	Flash Flood Warning	FFC	Floyd	2 hr
May 21, 12:34 AM EDT	Severe Thunderstorm Warning	FFC	Haralson	41 min
May 21, 12:50 AM EDT	Severe Thunderstorm Warning	FFC	Banks, Barrow, Cobb, DeKalb, Forsyth, Fulton and 3 more	19 min
May 21, 1:00 AM EDT	Severe Thunderstorm Warning	FFC	Carroll, Douglas, Haralson, Paulding	26 min
May 21, 1:10 AM EDT	Severe Thunderstorm Warning	FFC	Carroll, Haralson	27 min
May 21, 1:48 AM EDT	Flash Flood Warning	FFC	Cobb, DeKalb, Douglas, Fulton, Gwinnett, Paulding	4 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.5 hours before the alert went out and 226 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1162 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 904 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 3.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 19, 8:02 PM EDT	Mesoscale Discussion	SPC	Catoosa, Dade, Dawson, Fannin, Gilmer, Gordon and 7 more	88 min
May 20, 3:36 PM EDT	Tornado Watch	SPC	Catoosa, Chattooga, Dade, Walker	8 hr
May 20, 2:07 AM EDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Carlisle, Christian, Crittenden, Daviess and 16 more	83 min
May 20, 3:15 AM EDT	Tornado Watch	SPC	Ballard, Caldwell, Carlisle, Crittenden, Daviess, Hancock and 11 more	4 hr
May 20, 11:19 AM EDT	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 46 more	2 hr
May 20, 1:10 PM EDT	Tornado Watch	SPC	Bath, Bell, Bourbon, Boyd, Breathitt, Carter and 39 more	5 hr
May 20, 2:09 PM EDT	Tornado Watch	SPC	Ballard, Calloway, Carlisle, Fulton, Graves, Hickman and 3 more	8 hr
May 20, 2:48 PM EDT	Mesoscale Discussion	SPC	Allen, Barren, Butler, Christian, Edmonson, Logan and 5 more	117 min
May 20, 3:42 PM EDT	Mesoscale Discussion	SPC	Floyd, Harlan, Johnson, Knott, Lawrence, Letcher and 3 more	2 hr
May 20, 4:33 PM EDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Calloway, Carlisle, Christian, Fulton and 7 more	117 min
May 20, 6:13 PM EDT	Mesoscale Discussion	SPC	Bell, Boyle, Breathitt, Clark, Clay, Estill and 25 more	62 min
May 20, 1:34 PM EDT	Mesoscale Discussion	SPC	Crockett, Dyer, Fayette, Haywood, Lake, Lauderdale and 2 more	116 min

Nearby

Tornado Watches in Tennessee, 2025 Tornado Watches in Kentucky, 2025 Tornado Watches in Georgia, 2025 Every tornado watch in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.