Alert archive / Kentucky / Tornado Watches in 2021

Tornado Watch 554

December 10, 20214 states

The Storm Prediction Center issued this tornado watch at Dec 10, 2021, 7:21 PM EST for 4 states. It was in force for 10 hr.

The area

The outline as issued.

The facts

Issued
Dec 10, 2021, 7:21 PM EST (00:21 UTC)
Expired
Dec 11, 2021, 5:14 AM EST
In force
10 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
70 kt
All 80 counties

Clark County, IN, Crawford County, IN, Dubois County, IN, Floyd County, IN, Harrison County, IN, Jefferson County, IN, Orange County, IN, Perry County, IN, Scott County, IN, Washington County, IN, Allen County, KY, Anderson County, KY, Barren County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Christian County, KY, Edmonson County, KY, Franklin County, KY, Grayson County, KY, Green County, KY, Hancock County, KY, Hardin County, KY, Hart County, KY, Henry County, KY, Jefferson County, KY, Larue County, KY, Logan County, KY, Marion County, KY, Meade County, KY, Metcalfe County, KY, Monroe County, KY, Muhlenberg County, KY, Nelson County, KY, Ohio County, KY, Oldham County, KY, Shelby County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Todd County, KY, Trimble County, KY, Warren County, KY, Washington County, KY, Alcorn County, MS, Benton County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Pontotoc County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Benton County, TN, Cheatham County, TN, Chester County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Macon County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wayne County, TN, Williamson County, TN, Wilson County, TN

The radar

The Ft Campbell radar (KHPX), 69 km from the middle of the area, began a volume at 00:21 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
70%
One or more EF2 to EF5 tornadoes
40%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 10, 8:12 PM ESTTornado WarningPAHHopkins, McLean, Muhlenberg48 min
Dec 10, 8:48 PM ESTTornado WarningLMKOhio57 min
Dec 10, 9:19 PM ESTTornado WarningPAHChristian, Hopkins, Muhlenberg41 min
Dec 10, 9:24 PM ESTSevere Thunderstorm WarningLMKBreckinridge, Hancock36 min
Dec 10, 9:26 PM ESTTornado WarningPAHCaldwell, Christian, Hopkins, Trigg34 min
Dec 10, 9:32 PM ESTTornado WarningLMKOhio30 min
Dec 10, 9:48 PM ESTTornado WarningPAHChristian, Hopkins, Muhlenberg42 min
Dec 10, 10:21 PM ESTTornado WarningLMKOhio39 min
Dec 10, 10:25 PM ESTTornado WarningPAHMcLean, Muhlenberg20 min
Dec 10, 10:37 PM ESTTornado WarningLMKHarrison17 min
Dec 10, 11:09 PM ESTTornado Warning Tornado observedConsiderable damage threatPAHCaldwell, Christian, Hopkins, Lyon51 min
Dec 10, 11:36 PM ESTTornado Warning Tornado observedConsiderable damage threatPAHHopkins, McLean, Muhlenberg39 min
Dec 10, 11:42 PM ESTTornado Warning Tornado observedConsiderable damage threatLMKOhio63 min
Dec 10, 11:44 PM ESTTornado Warning EmergencyTornado observedCatastrophic damage threatPAHHopkins, Muhlenberg31 min
Dec 10, 11:58 PM ESTTornado Warning EmergencyTornado observedCatastrophic damage threatPAHMcLean, Muhlenberg17 min
Dec 11, 12:07 AM ESTTornado Warning Tornado observedConsiderable damage threatLMKBreckinridge, Grayson, Hancock53 min
Dec 11, 12:29 AM ESTTornado Warning Tornado observedOHXStewart46 min
Dec 11, 12:51 AM ESTTornado Warning Tornado observedConsiderable damage threatLMKBreckinridge, Hardin, Meade39 min
Dec 11, 1:03 AM ESTTornado Warning Tornado observedConsiderable damage threatPAHChristian, Trigg42 min
Dec 11, 1:03 AM ESTTornado Warning Tornado observedConsiderable damage threatOHXMontgomery, Stewart16 min
Dec 11, 1:19 AM ESTSevere Thunderstorm WarningOHXMontgomery, Stewart41 min
Dec 11, 1:29 AM ESTTornado Warning Tornado observedConsiderable damage threatPAHTodd21 min
Dec 11, 1:36 AM ESTTornado Warning Tornado observedLMKLogan, Simpson39 min
Dec 11, 1:41 AM ESTSevere Thunderstorm WarningLMKBullitt, Nelson, Spencer34 min
Dec 11, 1:44 AM ESTTornado WarningLMKBullitt, Nelson, Shelby, Spencer46 min
Dec 11, 1:58 AM ESTTornado Warning Tornado observedLMKButler, Edmonson, Logan, Simpson, Warren47 min
Dec 11, 2:25 AM ESTSevere Thunderstorm WarningMEGBenton, Carroll, Chester, Decatur, Gibson, Hardeman and 2 more65 min
Dec 11, 2:27 AM ESTTornado Warning Tornado observedLMKBarren, Butler, Edmonson, Hart, Metcalfe, Warren48 min
Dec 11, 2:28 AM ESTTornado WarningLMKFranklin, Scott20 min
Dec 11, 2:28 AM ESTSevere Thunderstorm WarningOHXStewart21 min
Dec 11, 2:32 AM ESTTornado WarningMEGCarroll, Chester, Henderson, Madison28 min
Dec 11, 2:46 AM ESTFlash Flood WarningPAHCalloway, Christian, Todd, Trigg8 hr
Dec 11, 2:47 AM ESTSevere Thunderstorm Warning Considerable damage threatOHXDickson, Hickman, Houston, Humphreys, Lewis, Montgomery and 2 more73 min
Dec 11, 2:49 AM ESTSevere Thunderstorm WarningPAHChristian, Todd26 min
Dec 11, 2:53 AM ESTTornado WarningMEGBenton, Carroll, Decatur, Henderson25 min
Dec 11, 2:55 AM ESTTornado WarningLMKBarren, Green, Hart, Larue, Marion, Metcalfe and 1 more50 min
Dec 11, 3:03 AM ESTTornado WarningOHXHouston, Humphreys, Stewart27 min
Dec 11, 3:07 AM ESTTornado WarningOHXDickson, Hickman, Humphreys, Perry38 min
Dec 11, 3:16 AM ESTSevere Thunderstorm WarningLMKAnderson, Franklin, Harrison, Henry, Nelson, Scott and 3 more29 min
Dec 11, 3:16 AM ESTSevere Thunderstorm Warning Considerable damage threatLMKButler, Logan, Simpson, Warren44 min
Dec 11, 3:22 AM ESTTornado Warning Tornado observedLMKBoyle, Casey, Larue, Lincoln, Marion, Mercer and 1 more38 min
Dec 11, 3:23 AM ESTTornado WarningOHXDickson, Houston, Montgomery, Stewart37 min
Dec 11, 3:38 AM ESTTornado WarningOHXDickson, Hickman, Humphreys37 min
Dec 11, 3:39 AM ESTTornado WarningOHXCheatham, Dickson, Montgomery14 min
Dec 11, 3:41 AM ESTSevere Thunderstorm WarningMEGBenton, Marshall49 min
Dec 11, 3:47 AM ESTSevere Thunderstorm WarningOHXCheatham, Davidson, Dickson, Hickman, Lewis, Maury and 5 more58 min
Dec 11, 3:58 AM ESTTornado WarningOHXCheatham, Davidson, Dickson, Williamson32 min
Dec 11, 3:59 AM ESTTornado WarningOHXDavidson, Williamson31 min
Dec 11, 4:00 AM ESTFlash Flood WarningLMKBarren, Butler, Edmonson, Green, Hart, Logan and 3 more6 hr
Dec 11, 4:03 AM ESTSevere Thunderstorm WarningMEGAlcorn, Benton, Tippah42 min
Dec 11, 4:13 AM ESTSevere Thunderstorm WarningLMKAllen, Barren, Butler, Edmonson, Hart, Logan and 2 more32 min
Dec 11, 4:19 AM ESTSevere Thunderstorm WarningOHXDavidson, Hickman, Lewis, Marshall, Maury, Robertson and 5 more41 min
Dec 11, 4:21 AM ESTTornado WarningOHXDavidson, Sumner, Wilson39 min
Dec 11, 4:29 AM ESTSevere Thunderstorm Warning Destructive damage threatOHXDavidson, Rutherford, Smith, Sumner, Trousdale, Williamson and 1 more46 min
Dec 11, 4:30 AM ESTTornado WarningMEGHardin, McNairy21 min
Dec 11, 4:33 AM ESTTornado WarningOHXDavidson, Macon, Smith, Sumner, Trousdale, Wilson42 min
Dec 11, 4:46 AM ESTTornado WarningOHXClay, Macon, Sumner, Trousdale44 min
Dec 11, 4:47 AM ESTSevere Thunderstorm WarningLMKAllen, Barren, Edmonson, Grayson, Green, Hardin and 7 more28 min
Dec 11, 4:48 AM ESTSevere Thunderstorm WarningOHXLewis, Perry, Wayne42 min
Dec 11, 4:50 AM ESTSevere Thunderstorm Warning Considerable damage threatOHXClay, DeKalb, Jackson, Macon, Putnam, Smith and 3 more17 min
Dec 11, 4:56 AM ESTFlash Flood WarningLMKHarrison3 hr
Dec 11, 4:56 AM ESTTornado WarningOHXLewis, Perry, Wayne13 min
Dec 11, 4:59 AM ESTSevere Thunderstorm WarningMEGLafayette, Lee, Pontotoc, Union31 min
Dec 11, 5:03 AM ESTFlash Flood WarningMEGCalhoun, Lafayette, Lee, Pontotoc, Prentiss, Tallahatchie and 3 more2 hr
Dec 11, 5:07 AM ESTTornado WarningOHXClay, Jackson, Macon, Overton, Smith, Trousdale38 min
Dec 11, 5:11 AM ESTSevere Thunderstorm Warning Considerable damage threatOHXClay, Fentress, Jackson, Macon, Overton, Pickett and 4 more34 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

Nashville Metro, TN (KBNA), launched 00:00Z, 0.4 hours before the alert went out and 91 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, Nashville Metro, TN at 00:00Z on 2021-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 182 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, Nashville Metro, TN at 00:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 391 square meters per square second.1939587897Sfc1 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
182 J/kg
Mixed-layer CIN
-168 J/kg
Mixed-layer LCL
593 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
391 m²/s²
0-3 km storm-relative helicity
370 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

548 
WWUS20 KWNS 110019
SEL4  
SPC WW 110019
INZ000-KYZ000-MSZ000-TNZ000-110800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 554
NWS Storm Prediction Center Norman OK
620 PM CST Fri Dec 10 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Indiana
  Western to central Kentucky
  Northeast Mississippi
  Western to middle Tennessee

* Effective this Friday night and Saturday morning from 620 PM
  until 200 AM CST.

* Primary threats include...
  A few tornadoes likely with a couple intense tornadoes possible
  Scattered damaging winds likely with isolated significant gusts
    to 80 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Initially discrete supercells should spread northeast from
western portions of Kentucky and Tennessee, with an additional
supercell or two possibly developing out of northeast Mississippi.
Broader clustering and linear segments should develop late evening
into the overnight.

The tornado watch area is approximately along and 60 statute miles
east and west of a line from 45 miles north northeast of Louisville
KY to 5 miles southwest of Tupelo MS. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU4).

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 552...WW 553...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 70 knots. A few cumulonimbi with maximum tops to 400. Mean
storm motion vector 23040.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 11, 3:00 AM ESTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Lawrence, Limestone, Madison and 2 more90 min
Dec 11, 4:15 AM ESTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Marion90 min
Dec 11, 4:41 AM ESTTornado WatchSPCColbert, Cullman, DeKalb, Fayette, Franklin, Jackson and 10 more6 hr
Dec 11, 7:15 AM ESTMesoscale DiscussionSPCCullman, Fayette, Franklin, Jackson, Lamar, Lawrence and 6 more90 min
Dec 11, 8:34 AM ESTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 8 more86 min
Dec 11, 11:47 AM ESTMesoscale DiscussionSPCAutauga, Bullock, Butler, Chambers, Clarke, Clay and 15 more118 min
Dec 10, 8:18 PM ESTMesoscale DiscussionSPCBartholomew, Benton, Boone, Brown, Carroll, Cass and 37 more87 min
Dec 10, 8:47 PM ESTTornado WatchSPCBartholomew, Benton, Boone, Brown, Clay, Clinton and 24 more8 hr
Dec 10, 9:35 PM ESTMesoscale DiscussionSPCHarrison85 min
Dec 10, 10:36 PM ESTMesoscale DiscussionSPCVigo54 min
Dec 10, 11:25 PM ESTMesoscale DiscussionSPCBartholomew, Benton, Blackford, Boone, Brown, Carroll and 50 more95 min
Dec 11, 12:03 AM ESTTornado WatchSPCGibson, Pike, Posey, Spencer, Vanderburgh, Warrick5 hr
Dec 11, 12:08 AM ESTMesoscale DiscussionSPCDearborn, Decatur, Delaware, Fayette, Franklin, Hamilton and 16 more67 min
Dec 11, 12:20 AM ESTTornado WatchSPCAdams, Allen, Blackford, Carroll, Cass, Dearborn and 27 more6 hr
Dec 11, 12:28 AM ESTMesoscale DiscussionSPCClay, Daviess, Fountain, Gibson, Greene, Knox and 9 more92 min
Dec 11, 2:46 AM ESTMesoscale DiscussionSPCBartholomew, Brown, Daviess, Dearborn, Decatur, Delaware and 21 more59 min
Dec 10, 7:22 PM ESTMesoscale DiscussionSPCFulton, Graves, Hickman53 min
Dec 10, 8:41 PM ESTMesoscale DiscussionSPCFulton64 min
Dec 10, 9:48 PM ESTMesoscale DiscussionSPCCarlisle, Fulton, Graves, Hickman, Lyon, Marshall57 min
Dec 10, 10:48 PM ESTMesoscale DiscussionSPCCaldwell, Graves, Hopkins, Lyon, Marshall57 min
Dec 10, 11:09 PM ESTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 7 more96 min
Dec 10, 11:44 PM ESTMesoscale DiscussionSPCCaldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio61 min
Dec 11, 12:36 AM ESTMesoscale DiscussionSPCCalloway, Christian, Logan, Simpson, Todd, Trigg54 min
Dec 11, 12:53 AM ESTMesoscale DiscussionSPCBreckinridge, Bullitt, Grayson, Hardin, Jefferson, Meade and 3 more67 min
Dec 11, 2:02 AM ESTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more88 min
Dec 11, 2:05 AM ESTMesoscale DiscussionSPCBarren, Butler, Edmonson, Green, Hart, Logan and 2 more55 min
Dec 11, 2:27 AM ESTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more7 hr
Dec 11, 3:51 AM ESTMesoscale DiscussionSPCBoyle, Casey, Clark, Estill, Garrard, Jessamine and 4 more54 min
Dec 11, 6:32 AM ESTMesoscale DiscussionSPCBell, Breathitt, Clark, Clay, Estill, Jackson and 18 more88 min
Dec 10, 10:40 PM ESTMesoscale DiscussionSPCAlcorn, Benton, Coahoma, DeSoto, Lafayette, Marshall and 8 more2 hr
Dec 10, 11:00 PM ESTMesoscale DiscussionSPCBolivar, Carroll, Claiborne, Hinds, Holmes, Humphreys and 8 more90 min
Dec 10, 11:44 PM ESTTornado WatchSPCAlcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 21 more6 hr
Dec 11, 3:51 AM ESTMesoscale DiscussionSPCCheatham, Davidson, Rutherford, Williamson, Wilson84 min

Nearby

Tornado Watches in Kentucky, 2021Tornado Watches in Tennessee, 2021Tornado Watches in Indiana, 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.