Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 935
The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2021, 12:14 PM CDT for 35 counties in Alabama; 69 counties in Georgia; 26 counties in South Carolina. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 12, 2021, 12:14 PM CDT (17:14 UTC)
- Expired
- Jun 12, 2021, 2:45 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 130 counties
Autauga County, AL, Bibb County, AL, Blount County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Cullman County, AL, Elmore County, AL, Etowah County, AL, Fayette County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Lee County, AL, Limestone County, AL, Macon County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Baldwin County, GA, Bibb County, GA, Bleckley County, GA, Bulloch County, GA, Burke County, GA, Butts County, GA, Candler County, GA, Carroll County, GA, Chattahoochee County, GA, Clayton County, GA, Columbia County, GA, Coweta County, GA, Crawford County, GA, Dodge County, GA, Dooly County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Fayette County, GA, Glascock County, GA, Greene County, GA, Hancock County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jasper County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Laurens County, GA, Lincoln County, GA, Macon County, GA, Marion County, GA, McDuffie County, GA, Meriwether County, GA, Monroe County, GA, Montgomery County, GA, Morgan County, GA, Muscogee County, GA, Peach County, GA, Pike County, GA, Pulaski County, GA, Putnam County, GA, Richmond County, GA, Schley County, GA, Screven County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Tattnall County, GA, Taylor County, GA, Toombs County, GA, Treutlen County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Warren County, GA, Washington County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkes County, GA, Wilkinson County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Greenwood County, SC, Hampton County, SC, Jasper County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Williamsburg County, SC
The radar
The Atlanta radar (KFFC), 88 km from the middle of the area, began a volume at 17:17 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 nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 5.2 hours before the alert went out and 82 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
- 886 J/kg
- Mixed-layer CIN
- -34 J/kg
- Mixed-layer LCL
- 658 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 65 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.6
The text
As transmitted.
202
ACUS11 KWNS 121715
SWOMCD
SPC MCD 121714
SCZ000-GAZ000-ALZ000-121945-
Mesoscale Discussion 0935
NWS Storm Prediction Center Norman OK
1214 PM CDT Sat Jun 12 2021
Areas affected...portions of central Alabama into central Georgia
and much of South Carolina
Concerning...Severe potential...Watch unlikely
Valid 121714Z - 121945Z
Probability of Watch Issuance...5 percent
SUMMARY...A few damaging gusts may accompany the stronger storms. A
WW issuance is not expected given the isolated, brief nature of the
severe threat.
DISCUSSION...Thunderstorms continue to increase in coverage and
intensity in tandem with diurnal heating/boundary layer
destabilization per latest MRMS mosaic radar imagery, which has
shown 50 dBZ echoes reaching up to 25 kft in some cases. While
tropospheric winds and resultant deep-layer shear are quite weak,
80s to near 90F surface temperatures and 70+ F dewpoints are
resulting in 7-8 C/km 0-3 km lapse rates and 1000-2000 J/kg MLCAPE.
While most storms are expected to be short-lived, the more intense
wet downbursts, as well as strong outflows associated with any cold
pool mergers may support a few damaging gusts through the afternoon.
Still, organized severe potential seems unlikely given poor
kinematics/dynamic forcing, with any damaging gust potential being
isolated and brief. A WW issuance is not anticipated.
..Squitieri/Grams.. 06/12/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILM...CHS...CAE...GSP...JAX...FFC...BMX...HUN...
LAT...LON 32208131 31938233 31928383 32098570 32478735 33298822
33918809 34498756 34838705 34888659 34588622 34248584
33998560 33458410 33798305 34348222 34638130 34718043
34437996 33877941 33537951 33197995 32788057 32208131Nearby
Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in South Carolina, 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.