Alert archive / Tennessee / Tornado Watches in 2021

Tornado Watch 562

December 11, 202116 counties in Alabama; 17 counties in Mississippi; 32 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Dec 11, 2021, 3:41 AM CST for 16 counties in Alabama; 17 counties in Mississippi; 32 counties in Tennessee. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Dec 11, 2021, 3:41 AM CST (09:41 UTC)
Expired
Dec 11, 2021, 10:08 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt
All 65 counties

Colbert County, AL, Cullman County, AL, DeKalb County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Itawamba County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Webster County, MS, Bedford County, TN, Bledsoe County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Jackson County, TN, Lawrence County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN

The radar

The Columbus AFB radar (KGWX), 99 km from the middle of the area, began a volume at 09:44 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
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 11, 3:46 AM CSTTornado WarningOHXClay, Macon, Sumner, Trousdale44 min
Dec 11, 3:48 AM CSTSevere Thunderstorm WarningOHXLewis, Perry, Wayne42 min
Dec 11, 3:50 AM CSTSevere Thunderstorm Warning Considerable damage threatOHXClay, DeKalb, Jackson, Macon, Putnam, Smith and 3 more17 min
Dec 11, 3:56 AM CSTTornado WarningOHXLewis, Perry, Wayne13 min
Dec 11, 3:59 AM CSTSevere Thunderstorm WarningMEGLafayette, Lee, Pontotoc, Union31 min
Dec 11, 4:03 AM CSTFlash Flood WarningMEGCalhoun, Lafayette, Lee, Pontotoc, Prentiss, Tallahatchie and 3 more2 hr
Dec 11, 4:07 AM CSTTornado WarningOHXClay, Jackson, Macon, Overton, Smith, Trousdale38 min
Dec 11, 4:11 AM CSTSevere Thunderstorm Warning Considerable damage threatOHXClay, Fentress, Jackson, Macon, Overton, Pickett and 4 more34 min
Dec 11, 4:21 AM CSTSevere Thunderstorm WarningMEGItawamba, Lee, Prentiss, Tishomingo39 min
Dec 11, 4:25 AM CSTTornado WarningMEGItawamba, Prentiss, Tishomingo35 min
Dec 11, 4:29 AM CSTSevere Thunderstorm Warning Considerable damage threatHUNColbert, Franklin31 min
Dec 11, 4:33 AM CSTTornado WarningOHXClay, Fentress, Overton, Pickett42 min
Dec 11, 4:40 AM CSTTornado WarningHUNColbert, Franklin22 min
Dec 11, 4:57 AM CSTSevere Thunderstorm WarningMRXCampbell, Scott48 min
Dec 11, 4:58 AM CSTSevere Thunderstorm WarningMEGItawamba, Lee, Prentiss, Tishomingo47 min
Dec 11, 4:59 AM CSTSevere Thunderstorm Warning Considerable damage threatHUNColbert, Franklin, Lauderdale31 min
Dec 11, 5:01 AM CSTSevere Thunderstorm WarningOHXGiles, Lawrence, Lewis, Marshall, Maury29 min
Dec 11, 5:12 AM CSTSevere Thunderstorm WarningMEGItawamba, Lee, Prentiss, Tishomingo33 min
Dec 11, 5:21 AM CSTSevere Thunderstorm WarningOHXOverton, Putnam27 min
Dec 11, 5:27 AM CSTSevere Thunderstorm Warning Considerable damage threatHUNColbert, Franklin, Lauderdale33 min
Dec 11, 5:39 AM CSTSevere Thunderstorm WarningMRXCampbell, Scott51 min
Dec 11, 5:39 AM CSTSevere Thunderstorm WarningOHXGiles, Lawrence, Wayne36 min
Dec 11, 5:50 AM CSTSevere Thunderstorm WarningHUNColbert, Franklin, Lauderdale, Lawrence, Limestone, Morgan40 min
Dec 11, 5:56 AM CSTSevere Thunderstorm WarningOHXGiles, Lawrence, Marshall, Maury34 min
Dec 11, 6:12 AM CSTSevere Thunderstorm WarningHUNLincoln, Moore33 min
Dec 11, 6:13 AM CSTTornado WarningOHXGiles15 min
Dec 11, 6:29 AM CSTSevere Thunderstorm WarningMRXCampbell, Scott46 min
Dec 11, 6:41 AM CSTSevere Thunderstorm WarningHUNMadison34 min
Dec 11, 6:43 AM CSTFlash Flood WarningMRXScott4 hr
Dec 11, 6:58 AM CSTSevere Thunderstorm WarningOHXBedford, Coffee, Grundy, Warren32 min
Dec 11, 7:06 AM CSTSevere Thunderstorm WarningHUNCullman, Jackson, Lawrence, Limestone, Madison, Morgan24 min
Dec 11, 7:15 AM CSTSevere Thunderstorm WarningHUNFranklin30 min
Dec 11, 7:22 AM CSTSevere Thunderstorm WarningOHXCoffee, Grundy38 min
Dec 11, 7:23 AM CSTSevere Thunderstorm WarningMRXMarion, Sequatchie52 min
Dec 11, 7:23 AM CSTSevere Thunderstorm WarningMRXCampbell, Claiborne, Scott37 min
Dec 11, 7:31 AM CSTSevere Thunderstorm WarningHUNCullman, Jackson, Limestone, Madison, Marshall, Morgan29 min
Dec 11, 7:35 AM CSTTornado WarningOHXGrundy25 min
Dec 11, 7:43 AM CSTSevere Thunderstorm WarningHUNFranklin17 min
Dec 11, 8:02 AM CSTSevere Thunderstorm WarningMRXBledsoe, Bradley, Hamilton, McMinn, Meigs, Rhea and 1 more43 min
Dec 11, 8:18 AM CSTSevere Thunderstorm WarningMRXBledsoe, Meigs, Rhea, Roane42 min
Dec 11, 8:34 AM CSTSevere Thunderstorm WarningMRXBradley, Hamilton, Marion41 min

Discussions around it

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

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 9.7 hours before the alert went out and 168 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-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2021-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 906 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 381 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
906 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
579 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
381 m²/s²
0-3 km storm-relative helicity
413 m²/s²
Significant tornado parameter
1.9
Supercell composite
10.0

Open this sounding in Storm Lab

The text

As transmitted.

046 
WWUS20 KWNS 110939
SEL2  
SPC WW 110939
ALZ000-MSZ000-TNZ000-111700-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 562
NWS Storm Prediction Center Norman OK
340 AM CST Sat Dec 11 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northern Alabama
  North-central and northeastern Mississippi
  Middle and eastern Tennessee

* Effective this Saturday morning from 340 AM until 1100 AM CST.

* Primary threats include...
  A few tornadoes and a couple intense tornadoes possible
  Scattered damaging winds and isolated significant gusts to 75
    mph possible

SUMMARY...A belt of strong-severe thunderstorms, with embedded QLCS
mesovortices and bows, as well as isolated supercells in and ahead
of the line, should move through the watch area through the
remainder of the morning.  This activity poses a threat for severe
gusts, a few tornadoes, and isolated large hail.

The tornado watch area is approximately along and 45 statute miles
east and west of a line from 50 miles west southwest of Columbus MS
to 165 miles northeast of Huntsville AL. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 558...WW 559...WW
560...WW 561...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 24040.

...Edwards

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 11, 2:00 AM CSTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Lawrence, Limestone, Madison and 2 more90 min
Dec 11, 3:15 AM CSTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Marion90 min
Dec 11, 6:15 AM CSTMesoscale DiscussionSPCCullman, Fayette, Franklin, Jackson, Lamar, Lawrence and 6 more90 min
Dec 11, 7:34 AM CSTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 8 more86 min
Dec 11, 10:47 AM CSTMesoscale DiscussionSPCAutauga, Bullock, Butler, Chambers, Clarke, Clay and 15 more118 min
Dec 10, 6:21 PM CSTTornado WatchSPCAlcorn, Benton, Itawamba, Lafayette, Lee, Pontotoc and 4 more10 hr
Dec 10, 9:40 PM CSTMesoscale DiscussionSPCAlcorn, Benton, Coahoma, DeSoto, Lafayette, Marshall and 8 more2 hr
Dec 10, 10:00 PM CSTMesoscale DiscussionSPCBolivar, Carroll, Claiborne, Hinds, Holmes, Humphreys and 8 more90 min
Dec 10, 10:09 PM CSTMesoscale DiscussionSPCBenton, Bolivar, Calhoun, Carroll, Coahoma, DeSoto and 14 more96 min
Dec 10, 10:44 PM CSTTornado WatchSPCAlcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 21 more6 hr
Dec 10, 6:22 PM CSTMesoscale DiscussionSPCCrockett, Dyer, Gibson, Haywood, Lake, Lauderdale and 3 more53 min
Dec 10, 7:41 PM CSTMesoscale DiscussionSPCDyer, Gibson, Henry, Lake, Obion, Weakley64 min
Dec 10, 8:35 PM CSTMesoscale DiscussionSPCMontgomery85 min
Dec 10, 11:36 PM CSTMesoscale DiscussionSPCCheatham, Dickson, Henry, Houston, Montgomery, Robertson and 2 more54 min
Dec 11, 2:51 AM CSTMesoscale DiscussionSPCCheatham, Davidson, Rutherford, Williamson, Wilson84 min
Dec 11, 5:32 AM CSTMesoscale DiscussionSPCAnderson, Campbell, Claiborne, Fentress, Morgan, Pickett and 2 more88 min

Nearby

Tornado Watches in Tennessee, 2021Tornado Watches in Mississippi, 2021Tornado Watches in Alabama, 2021Every tornado watch in 2021

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.