Alert archive / Georgia / Mesoscale Discussions in 2021

Mesoscale Discussion 541

May 4, 20218 counties in Alabama; 30 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at May 4, 2021, 7:38 PM CDT for 8 counties in Alabama; 30 counties in Georgia. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: May 4, 2021, 7:38 PM CDT (00:38 UTC)
Expired: May 4, 2021, 9:15 PM CDT
In force: 97 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 151

All 38 counties

Barbour County, AL, Coffee County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Pike County, AL, Russell County, AL, Baker County, GA, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Crawford County, GA, Crisp County, GA, Dooly County, GA, Dougherty County, GA, Early County, GA, Harris County, GA, Houston County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Miller County, GA, Mitchell County, GA, Muscogee County, GA, Peach County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Terrell County, GA, Upson County, GA, Webster County, GA, Worth County, GA

The radar

The Ft Rucker radar (KEOX), 64 km from the middle of the area, began a volume at 00:38 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 00:00Z, 0.6 hours before the alert went out and 168 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 860 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: -136 m²/s²
0-3 km storm-relative helicity: 258 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

855 
ACUS11 KWNS 050039
SWOMCD
SPC MCD 050038 
GAZ000-ALZ000-050215-

Mesoscale Discussion 0541
NWS Storm Prediction Center Norman OK
0738 PM CDT Tue May 04 2021

Areas affected...Portions of southeastern AL into western GA

Concerning...Severe Thunderstorm Watch 151...

Valid 050038Z - 050215Z

The severe weather threat for Severe Thunderstorm Watch 151
continues.

SUMMARY...Strong to severe/damaging wind gusts will remain the
primary severe threat with a line of storms moving eastward this
evening.

DISCUSSION...Radar imagery from KMXX and KEOX show enhanced
low-level velocities associated with a QLCS moving across parts of
southeastern AL into western GA. Scattered strong to damaging winds
around 60 mph should continue to be the main severe threat in the
short term with the northern segment of this line, which remains
oriented more orthogonal to the west-southwesterly deep-layer flow.
With the loss of daytime heating, the airmass downstream of this
ongoing activity should gradually become less unstable. As a result,
most short-term guidance suggests that a slow reduction in the
overall intensity of the line should occur later this evening.

..Gleason.. 05/05/2021

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

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

LAT...LON   31638639 31978584 32328543 32638526 32998518 33108460
            32868392 32588353 31788362 31308403 31068451 31028547
            31068611 31358642 31638639

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 9:28 PM CDT	Mesoscale Discussion	SPC	Baker, Ben Hill, Berrien, Bibb, Bleckley, Brooks and 24 more	92 min

Nearby

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