Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 297
The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2021, 7:29 AM CDT for Calhoun County, Cleburne County, Talladega County, Alabama; 14 counties in Georgia. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Mar 28, 2021, 7:29 AM CDT (12:29 UTC)
- Expired
- Mar 28, 2021, 9:00 AM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 66...67
Counties Calhoun County, AL, Cleburne County, AL, Talladega County, AL, Bartow County, GA, Carroll County, GA, Cherokee County, GA, Cobb County, GA, Dawson County, GA, Forsyth County, GA, Habersham County, GA, Hall County, GA, Haralson County, GA, Lumpkin County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, White County, GA
The radar
The Atlanta radar (KFFC), 87 km from the middle of the area, began a volume at 12:31 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, 0.5 hours before the alert went out and 89 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
- 14 J/kg
- Mixed-layer CIN
- -127 J/kg
- Mixed-layer LCL
- 1016 m above ground
- 0-6 km bulk shear
- 68 kt
- 0-1 km storm-relative helicity
- 269 m²/s²
- 0-3 km storm-relative helicity
- 293 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
488
ACUS11 KWNS 281230
SWOMCD
SPC MCD 281229
GAZ000-ALZ000-281400-
Mesoscale Discussion 0297
NWS Storm Prediction Center Norman OK
0729 AM CDT Sun Mar 28 2021
Areas affected...Parts of east central Alabama through northern
Georgia
Concerning...Severe Thunderstorm Watch 66...67...
Valid 281229Z - 281400Z
The severe weather threat for Severe Thunderstorm Watch 66, 67
continues.
SUMMARY...A weakening squall line may continue to pose some risk for
localized potentially damaging wind gusts into mid morning across
the Piedmont of east central Alabama through northern Georgia,
including portions of the Greater Atlanta metropolitan area.
However, new severe weather watches are not currently anticipated.
DISCUSSION...Cloud cover appears likely to inhibit or slow
pre-frontal and squall line boundary layer warming across the
Piedmont early this morning, with model forecast soundings
indicating some further moistening sufficient to contribute to only
generally weak boundary-layer CAPE prior to the arrival of the
approaching remnant squall line. While southwesterly flow remains
as strong as 40-50 kt along this corridor just off the surface, this
is forecast to slowly begin to weaken during the next few hours,
which should also continue to gradually reduce the risk for severe
wind gusts.
..Kerr.. 03/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GSP...FFC...BMX...
LAT...LON 33868575 34298512 34668425 34798390 34598332 34148412
33558501 33168662 33418663 33868575SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 27, 10:45 PM CDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lauderdale, Lawrence, Limestone, Madison and 3 more | 90 min |
| Mar 27, 11:27 PM CDT | Tornado Watch | SPC | Blount, Colbert, Cullman, DeKalb, Fayette, Franklin and 11 more | 8 hr |
| Mar 28, 1:25 AM CDT | Mesoscale Discussion | SPC | Jackson | 2 hr |
| Mar 28, 1:57 AM CDT | Mesoscale Discussion | SPC | Blount, Colbert, Cullman, DeKalb, Etowah, Fayette and 11 more | 93 min |
| Mar 28, 4:56 AM CDT | Mesoscale Discussion | SPC | Blount, Cullman, DeKalb, Etowah, Marshall, Walker | 94 min |
| Mar 28, 5:10 AM CDT | Severe Thunderstorm Watch | SPC | Bibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 12 more | 5 hr |
| Mar 28, 9:14 AM CDT | Mesoscale Discussion | SPC | Autauga, Chambers, Chilton, Clay, Coosa, Dallas and 6 more | 61 min |
| Mar 28, 11:38 AM CDT | Mesoscale Discussion | SPC | Baldwin, Bibb, Bleckley, Burke, Butts, Columbia and 34 more | 3 hr |
| Mar 28, 4:51 PM CDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 46 more | 54 min |
Nearby
Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Alabama, 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.