Alert archive / Tennessee / Mesoscale Discussions in 2021

Mesoscale Discussion 1992

December 10, 2021Fulton County, Kentucky; Dunklin County, Pemiscot County, Missouri; 6 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 7:41 PM CST for Fulton County, Kentucky; Dunklin County, Pemiscot County, Missouri; 6 counties in Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Dec 10, 2021, 7:41 PM CST (01:41 UTC)
Expired
Dec 10, 2021, 8:45 PM CST
In force
64 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 552

Counties Fulton County, KY, Dunklin County, MO, Pemiscot County, MO, Dyer County, TN, Gibson County, TN, Henry County, TN, Lake County, TN, Obion County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 100 km from the middle of the area, began a volume at 01:42 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 1.7 hours before the alert went out and 171 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, Little Rock, AR at 00:00Z on 2021-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1725 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 00:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 398 square meters per square second.1939587897117Sfc1 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
1725 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
759 m above ground
0-6 km bulk shear
78 kt
0-1 km storm-relative helicity
398 m²/s²
0-3 km storm-relative helicity
420 m²/s²
Significant tornado parameter
4.8
Supercell composite
16.2

Open this sounding in Storm Lab

The text

As transmitted.

051 
ACUS11 KWNS 110142
SWOMCD
SPC MCD 110141 
TNZ000-KYZ000-MOZ000-ARZ000-110245-

Mesoscale Discussion 1992
NWS Storm Prediction Center Norman OK
0741 PM CST Fri Dec 10 2021

Areas affected...Northeast Arkansas...southern Missouri...northwest
Tennessee...and southwest Kentucky.

Concerning...Tornado Watch 552...

Valid 110141Z - 110245Z

The severe weather threat for Tornado Watch 552 continues.

SUMMARY...A strong to potentially violent tornado is ongoing in far
northeastern Arkansas and is expected to persist.

DISCUSSION...A mature and very strong supercell in northeast
Arkansas is currently producing a very strong to potentially violent
tornado. The downstream airmass remains very favorable with
dewpoints near 70, strengthening/backing surface flow, and 0-1 km
SRH in excess of 400 m2/s2 per KNQA VWP. This is yielding STP around
5. Given the favorable downstream environment with no convection to
disrupt this storm, expect the significant tornado threat to
continue for at least a few more hours as this discrete, long-track
supercell continues northeast.

..Bentley/Grams.. 12/11/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PAH...MEG...

LAT...LON   35868917 35859018 35999035 36209014 36588927 36708865
            36608832 36378812 36258832 35868917

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 10, 6:21 PM CSTTornado WatchSPCAllen, Anderson, Barren, Breckinridge, Bullitt, Butler and 28 more10 hr
Dec 10, 6:22 PM CSTMesoscale DiscussionSPCFulton, Graves, Hickman53 min
Dec 10, 8:35 PM CSTMesoscale DiscussionSPCAllen, Barren, Breckinridge, Bullitt, Butler, Caldwell and 26 more85 min
Dec 10, 8:48 PM CSTMesoscale DiscussionSPCCarlisle, Fulton, Graves, Hickman, Lyon, Marshall57 min
Dec 10, 9:48 PM CSTMesoscale DiscussionSPCCaldwell, Graves, Hopkins, Lyon, Marshall57 min
Dec 10, 10:09 PM CSTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 7 more96 min
Dec 10, 10:44 PM CSTMesoscale DiscussionSPCCaldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio61 min
Dec 10, 11:03 PM CSTTornado WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more5 hr
Dec 10, 11:08 PM CSTMesoscale DiscussionSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more67 min
Dec 10, 11:20 PM CSTTornado WatchSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more6 hr
Dec 10, 11:28 PM CSTMesoscale DiscussionSPCUnion92 min
Dec 10, 11:36 PM CSTMesoscale DiscussionSPCCalloway, Christian, Logan, Simpson, Todd, Trigg54 min
Dec 10, 11:53 PM CSTMesoscale DiscussionSPCBreckinridge, Bullitt, Grayson, Hardin, Jefferson, Meade and 3 more67 min
Dec 11, 1:02 AM CSTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more88 min
Dec 11, 1:05 AM CSTMesoscale DiscussionSPCBarren, Butler, Edmonson, Green, Hart, Logan and 2 more55 min
Dec 11, 1:27 AM CSTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more7 hr
Dec 11, 2:51 AM CSTMesoscale DiscussionSPCBoyle, Casey, Clark, Estill, Garrard, Jessamine and 4 more54 min
Dec 11, 5:32 AM CSTMesoscale DiscussionSPCBell, Breathitt, Clark, Clay, Estill, Jackson and 18 more88 min
Dec 10, 7:02 PM CSTMesoscale DiscussionSPCCallaway, Crawford, Dent, Franklin, Gasconade, Iron and 16 more58 min
Dec 10, 7:54 PM CSTMesoscale DiscussionSPCChristian, Crawford, Dallas, Dent, Douglas, Greene and 10 more2 hr
Dec 10, 9:40 PM CSTMesoscale DiscussionSPCDunklin, Pemiscot2 hr
Dec 10, 10:44 PM CSTTornado WatchSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 34 more6 hr
Dec 11, 2:00 AM CSTMesoscale DiscussionSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 41 more90 min
Dec 11, 2:51 AM CSTMesoscale DiscussionSPCCheatham, Davidson, Rutherford, Williamson, Wilson84 min
Dec 11, 3:41 AM CSTTornado WatchSPCBedford, Bledsoe, Cannon, Clay, Coffee, Cumberland and 26 more6 hr
Dec 11, 6:15 AM CSTMesoscale DiscussionSPCBedford, Bledsoe, Cannon, Coffee, Cumberland, DeKalb and 12 more90 min

Nearby

Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Kentucky, 2021Every mesoscale discussion 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.