Alert archive / Arkansas / Mesoscale Discussions in 2021

Mesoscale Discussion 2001

December 10, 20216 states

The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 10:09 PM CST for 6 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Dec 10, 2021, 10:09 PM CST (04:09 UTC)
Expired
Dec 10, 2021, 11:45 PM CST
In force
96 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 552
All 81 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, St. Francis County, AR, Woodruff County, AR, Massac County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Washington County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 72 km from the middle of the area, began a volume at 04:11 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, 4.2 hours before the alert went out and 27 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.

489 
ACUS11 KWNS 110409
SWOMCD
SPC MCD 110409 
TNZ000-KYZ000-MSZ000-ILZ000-MOZ000-ARZ000-110545-

Mesoscale Discussion 2001
NWS Storm Prediction Center Norman OK
1009 PM CST Fri Dec 10 2021

Areas affected...Eastern Arkansas...northern Mississippi...southeast
Missouri...western Tennessee...and western Kentucky.

Concerning...Tornado Watch 552...

Valid 110409Z - 110545Z

The severe weather threat for Tornado Watch 552 continues.

SUMMARY...Watch 552 will be replaced by a new watch by 05Z. Some
additional counties may be added across southeast Arkansas and
central Mississippi.

DISCUSSION...Watch 552 expires at 05Z and will need to be replaced
by a new tornado watch. The greatest tornado threat will remain in
northern portions of this replacement watch where the forcing is
stronger. However, the shear and instability profile remains
favorable across eastern Arkansas and northern Mississippi and
therefore, tornadoes remain possible in this region, especially if
additional discrete storms can develop ahead of the main line after
08Z as some 00Z CAM guidance suggests.

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

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

ATTN...WFO...OHX...PAH...MEG...JAN...LZK...SHV...

LAT...LON   33879328 35159153 35969037 37048933 37368838 37368769
            36688758 34858861 34798860 33468974 33239012 33139026
            33189080 33119195 33249229 33879328

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 10, 6:22 PM CSTMesoscale DiscussionSPCCraighead, Greene, Jackson, Mississippi, Poinsett53 min
Dec 10, 6:34 PM CSTTornado WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more4 hr
Dec 10, 6:37 PM CSTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more83 min
Dec 10, 6:51 PM CSTTornado WatchSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more4 hr
Dec 10, 7:34 PM CSTMesoscale DiscussionSPCClark, Crittenden, Cross, Faulkner, Garland, Grant and 16 more86 min
Dec 10, 7:54 PM CSTMesoscale DiscussionSPCBoone, Carroll, Crawford, Franklin, Johnson, Logan and 7 more2 hr
Dec 10, 9:40 PM CSTMesoscale DiscussionSPCArkansas, Clark, Cleveland, Craighead, Crittenden, Cross and 13 more2 hr
Dec 10, 10:00 PM CSTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Desha and 5 more90 min
Dec 10, 10:44 PM CSTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 16 more6 hr
Dec 11, 2:00 AM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Desha and 4 more90 min
Dec 10, 7:02 PM CSTMesoscale DiscussionSPCCalhoun, Greene, Jersey, Macoupin, Madison, Monroe and 4 more58 min
Dec 10, 7:18 PM CSTMesoscale DiscussionSPCChampaign, Christian, Clark, Clay, Coles, Crawford and 18 more87 min
Dec 10, 7:47 PM CSTTornado WatchSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 21 more8 hr
Dec 10, 8:53 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Coles and 21 more97 min
Dec 10, 9:36 PM CSTMesoscale DiscussionSPCClark, Coles, Cumberland, Edgar, Effingham, Shelby54 min
Dec 10, 11:03 PM CSTTornado WatchSPCAlexander, Clinton, Edwards, Fayette, Franklin, Gallatin and 17 more5 hr
Dec 10, 11:28 PM CSTMesoscale DiscussionSPCAlexander, Clark, Clay, Coles, Crawford, Cumberland and 24 more92 min
Dec 10, 6:21 PM CSTTornado WatchSPCAllen, Anderson, Barren, Breckinridge, Bullitt, Butler and 28 more10 hr
Dec 10, 7:41 PM CSTMesoscale DiscussionSPCFulton64 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, 10:44 PM CSTMesoscale DiscussionSPCCaldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio61 min
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, 11:36 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 11, 3:15 AM CSTMesoscale DiscussionSPCAlcorn, Benton, Calhoun, Carroll, Chickasaw, Choctaw and 21 more90 min
Dec 11, 3:41 AM CSTTornado WatchSPCCalhoun, Carroll, Chickasaw, Choctaw, Clay, Grenada and 11 more6 hr
Dec 11, 6:15 AM CSTMesoscale DiscussionSPCClay, Lowndes, Monroe, Oktibbeha90 min
Dec 11, 2:51 AM CSTMesoscale DiscussionSPCCheatham, Davidson, Rutherford, Williamson, Wilson84 min

Nearby

Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Mississippi, 2021Mesoscale Discussions in Tennessee, 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.