Alert archive / Georgia / Mesoscale Discussions in 2021

Mesoscale Discussion 1664

August 31, 20214 counties in Alabama; Holmes County, Florida; 18 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Aug 31, 2021, 6:44 PM CDT for 4 counties in Alabama; Holmes County, Florida; 18 counties in Georgia. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Aug 31, 2021, 6:44 PM CDT (23:44 UTC)
Expired
Aug 31, 2021, 8:15 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 23 counties

Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Holmes County, FL, Baker County, GA, Calhoun County, GA, Clay County, GA, Dooly County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Miller County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Stewart County, GA, Sumter County, GA, Taylor County, GA, Terrell County, GA, Webster County, GA

The radar

The Ft Rucker radar (KEOX), 43 km from the middle of the area, began a volume at 23:46 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 11.7 hours before the alert went out and 145 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, Tallahassee Rgnl, FL at 12:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 822 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, Tallahassee Rgnl, FL at 12:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.1939Sfc1 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
822 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
903 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

062 
ACUS11 KWNS 312344
SWOMCD
SPC MCD 312344 
GAZ000-FLZ000-ALZ000-010115-

Mesoscale Discussion 1664
NWS Storm Prediction Center Norman OK
0644 PM CDT Tue Aug 31 2021

Areas affected...Southeastern Alabama into southwestern Georgia

Concerning...Severe potential...Watch unlikely 

Valid 312344Z - 010115Z

Probability of Watch Issuance...20 percent

SUMMARY...A brief, weak tornado or two may occur in the next 1-2
hours before the thermodynamic and kinematic environment will become
less favorable. No watch is anticipated.

DISCUSSION...A few marginal supercells with weak rotation have
developed within a narrow band of better buoyancy where temperatures
have risen into the low 80s F. At least one tornado was reported in
the vicinity of Dothan, AL within the last hour and another weak TDS
apparent on 23:39 UTC KEOX velocity imagery. With low-level winds
continuing to veer, nocturnal cooling beginning in the next couple
of hours, and mid-level subsidence moving overhead (per water vapor
imagery), the threat for a brief, weak tornado or two will likely
only last another 1-2 hours. No watch is expected this
afternoon/evening.

..Wendt/Edwards.. 08/31/2021

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

ATTN...WFO...FFC...TAE...BMX...

LAT...LON   31248599 32258495 32588434 32488379 32208372 31368414
            31058467 30848550 30848602 31008612 31248599

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 31, 4:31 AM CDTMesoscale DiscussionSPCBullock, Chambers, Cleburne, Crenshaw, Lee, Macon and 4 more89 min
Aug 31, 7:44 AM CDTMesoscale DiscussionSPCHenry2 hr
Aug 31, 3:49 PM CDTMesoscale DiscussionSPCGeneva, Henry, Houston, Russell116 min
Aug 31, 1:03 PM CDTMesoscale DiscussionSPCBanks, Barrow, Butts, Carroll, Cherokee, Clarke and 47 more117 min

Nearby

Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Florida, 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.