Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1987
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 6:37 PM CST for 16 counties in Arkansas; 5 counties in Oklahoma. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 6:37 PM CST (00:37 UTC)
- Expired
- Dec 10, 2021, 8:00 PM CST
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 21 counties
Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 33 km from the middle of the area, began a volume at 00:41 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
Springfield, MO (KSGF), launched 00:00Z, 0.6 hours before the alert went out and 173 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
- 637 J/kg
- Mixed-layer CIN
- -23 J/kg
- Mixed-layer LCL
- 1113 m above ground
- 0-6 km bulk shear
- 80 kt
- 0-1 km storm-relative helicity
- 344 m²/s²
- 0-3 km storm-relative helicity
- 300 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 8.4
The text
As transmitted.
220
ACUS11 KWNS 110037
SWOMCD
SPC MCD 110037
ARZ000-OKZ000-110200-
Mesoscale Discussion 1987
NWS Storm Prediction Center Norman OK
0637 PM CST Fri Dec 10 2021
Areas affected...Eastern Oklahoma and western Arkansas.
Concerning...Severe potential...Watch possible
Valid 110037Z - 110200Z
Probability of Watch Issuance...60 percent
SUMMARY...A new tornado watch may be needed across portions of
eastern Oklahoma and western Arkansas.
DISCUSSION...Rapid storm development has occurred along the dryline
near the Oklahoma/Arkansas border as the strong ascent overspreads
the warm sector. These storms will likely pose a threat for large
hail, damaging winds, and a few tornadoes as they continue east into
the overnight hours. A new tornado watch may be needed to cover this
threat west of watch 552.
..Bentley/Grams.. 12/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SHV...TSA...
LAT...LON 34419447 34499547 35089542 36449447 36489313 36459213
35829252 34589399 34419447SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 6:22 PM CST | Mesoscale Discussion | SPC | Craighead, Greene, Jackson, Mississippi, Poinsett | 53 min |
| Dec 10, 6:34 PM CST | Tornado Watch | SPC | Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more | 4 hr |
| Dec 10, 6:51 PM CST | Tornado Watch | SPC | Baxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more | 4 hr |
| Dec 10, 7:34 PM CST | Mesoscale Discussion | SPC | Clark, Crittenden, Cross, Faulkner, Garland, Grant and 16 more | 86 min |
| Dec 10, 7:54 PM CST | Mesoscale Discussion | SPC | Boone, Carroll, Crawford, Franklin, Johnson, Logan and 7 more | 2 hr |
| Dec 10, 9:40 PM CST | Mesoscale Discussion | SPC | Arkansas, Clark, Cleveland, Craighead, Crittenden, Cross and 13 more | 2 hr |
| Dec 10, 10:00 PM CST | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 5 more | 90 min |
| Dec 10, 10:09 PM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 17 more | 96 min |
| Dec 10, 10:44 PM CST | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 16 more | 6 hr |
| Dec 11, 2:00 AM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Desha and 4 more | 90 min |
Nearby
Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Oklahoma, 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.