Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1982
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 4:45 PM CST for 6 states. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 4:45 PM CST (22:45 UTC)
- Expired
- Dec 10, 2021, 6:15 PM CST
- In force
- 90 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 552
All 70 counties
Arkansas County, AR, Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Grant County, AR, Greene County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Union County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Coahoma County, MS, DeSoto County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tate County, MS, Tunica County, MS, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Haywood County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN
The radar
The Memphis radar (KNQA), 82 km from the middle of the area, began a volume at 22:45 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 12:00Z, 10.8 hours before the alert went out and 131 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.
- Mixed-layer CAPE
- 547 J/kg
- Mixed-layer CIN
- -54 J/kg
- Mixed-layer LCL
- 475 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 199 m²/s²
- 0-3 km storm-relative helicity
- 200 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 2.9
The text
As transmitted.
509
ACUS11 KWNS 102246
SWOMCD
SPC MCD 102245
KYZ000-TNZ000-ILZ000-MSZ000-MOZ000-ARZ000-110015-
Mesoscale Discussion 1982
NWS Storm Prediction Center Norman OK
0445 PM CST Fri Dec 10 2021
Areas affected...Eastern Arkansas...southeast Missouri...southern
Illinois...southeast Indiana...and western Kentucky.
Concerning...Tornado Watch 552...
Valid 102245Z - 110015Z
The severe weather threat for Tornado Watch 552 continues.
SUMMARY...A slow increase in storm intensity/coverage is expected
over the next 1 to 2 hours.
DISCUSSION...Initial storms which developed near Little Rock have
not shown much organization thus far. In addition, weak cellular
convection is developing across much of the Mississippi River
region. However, a strong capping inversion, sampled by the 19Z LZK
RAOB is likely limiting more robust storm development thus far. As
heights continue to fall this evening, expect these warmer mid-level
temperatures to erode further and expect greater storm coverage and
intensity. Once mature supercells can develop, all severe hazards
remain possible as the environment remains favorable with 0 to 1 km
shear now in excess of 35 knots per KLZK VWP.
..Bentley.. 12/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...
LAT...LON 37669019 37938924 37578816 35588870 34219005 34039184
34249245 34759248 37669019SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 1:35 PM CST | Mesoscale Discussion | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Cross and 22 more | 2 hr |
| Dec 10, 3:07 PM CST | Tornado Watch | SPC | Arkansas, Clark, Clay, Cleburne, Cleveland, Conway and 37 more | 11 hr |
| Dec 10, 4:20 PM CST | Mesoscale Discussion | SPC | Hempstead, Howard, Little River, Miller, Pike, Sevier | 85 min |
| Dec 10, 5:17 PM CST | Tornado Watch | SPC | Adams, Bond, Brown, Calhoun, Cass, Christian and 18 more | 6 hr |
| Dec 10, 5:27 PM CST | Mesoscale Discussion | SPC | Calhoun, Jersey | 3 hr |
| Dec 10, 5:52 PM CST | Mesoscale Discussion | SPC | Allen, Breckinridge, Bullitt, Butler, Christian, Daviess and 17 more | 83 min |
| Dec 10, 5:17 PM CST | Mesoscale Discussion | SPC | Alcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 9 more | 88 min |
| Dec 10, 2:44 PM CST | Mesoscale Discussion | SPC | Audrain, Boone, Carroll, Chariton, Clark, Cooper and 13 more | 2 hr |
Nearby
Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Missouri, 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.