Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 427
The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2021, 5:56 PM CDT for 7 counties in Alabama; 14 counties in Georgia. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Apr 24, 2021, 5:56 PM CDT (22:56 UTC)
- Expired
- Apr 24, 2021, 7:30 PM CDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 108...109
All 21 counties
Barbour County, AL, Bullock County, AL, Coffee County, AL, Dale County, AL, Henry County, AL, Houston County, AL, Pike County, AL, Baker County, GA, Calhoun County, GA, Clay County, GA, Colquitt County, GA, Cook County, GA, Dougherty County, GA, Early County, GA, Miller County, GA, Mitchell County, GA, Quitman County, GA, Randolph County, GA, Terrell County, GA, Tift County, GA, Worth County, GA
The radar
The Ft Rucker radar (KEOX), 46 km from the middle of the area, began a volume at 22:58 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
Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 10.9 hours before the alert went out and 144 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
- 175 J/kg
- Mixed-layer CIN
- -61 J/kg
- Mixed-layer LCL
- 544 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- 447 m²/s²
- 0-3 km storm-relative helicity
- 570 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.7
The text
As transmitted.
541
ACUS11 KWNS 242256
SWOMCD
SPC MCD 242256
GAZ000-ALZ000-250030-
Mesoscale Discussion 0427
NWS Storm Prediction Center Norman OK
0556 PM CDT Sat Apr 24 2021
Areas affected...Parts of southern Alabama and southwestern Georgia
Concerning...Severe Thunderstorm Watch 108...109...
Valid 242256Z - 250030Z
The severe weather threat for Severe Thunderstorm Watch 108, 109
continues.
SUMMARY...Potential still exists for the evolution of another
upscale growing and organizing cluster of storms which could pose
increasing risk for damaging wind gusts across parts of southeastern
Alabama into southwestern Georgia through 7-9 PM EDT.
DISCUSSION...Lift aided by low-level convergence along a pre-cold
frontal wind shift advancing across southern Alabama, and warm
advection along a sharp, quasi-stationary, convectively reinforced
surface front across southwestern/southern Georgia, is maintaining
vigorous new thunderstorm development. This appears to be occurring
in the presence of moderate to large CAPE on the order of 1000-2000+
J/kg, and strong deep-layer shear beneath 50-70 kt
west-southwesterly flow around 500 mb. Low-level shear also remains
rather strong, with 40 kt southwesterly flow around 850 mb roughly
aligned with the wind shift.
Given this environment, the surface boundary intersection east of
Troy, AL into the Albany, GA vicinity might provide a focus for
consolidating, upscale growing convection during the next few hours.
If this occurs, the evolution of an organizing convective system
capable of producing damaging wind gusts could still evolve through
early evening.
..Kerr.. 04/24/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FFC...TAE...BMX...MOB...
LAT...LON 31688371 31268323 30878395 31038518 31168585 31188633
31498650 31738623 32138568 32148523 32018477 31858440
31688371SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 1:00 AM CDT | Mesoscale Discussion | SPC | Baldwin, Coffee, Conecuh, Covington, Escambia, Geneva and 2 more | 3 hr |
| Apr 24, 1:00 AM CDT | Mesoscale Discussion | SPC | Baldwin, Coffee, Conecuh, Covington, Escambia, Geneva and 2 more | 3 hr |
| Apr 24, 1:23 AM CDT | Tornado Watch | SPC | Baldwin, Clarke, Conecuh, Covington, Escambia, Mobile and 2 more | 8 hr |
| Apr 24, 3:04 AM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile, Washington | 116 min |
| Apr 24, 4:26 AM CDT | Mesoscale Discussion | SPC | Conecuh, Covington, Escambia, Monroe, Washington | 2 hr |
| Apr 24, 5:22 AM CDT | Tornado Watch | SPC | Coffee, Dale, Geneva, Henry, Houston | 9 hr |
| Apr 24, 7:29 AM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Geneva, Henry, Houston | 91 min |
| Apr 24, 12:29 PM CDT | Mesoscale Discussion | SPC | Baldwin, Choctaw, Clarke, Conecuh, Escambia, Marengo and 4 more | 2 hr |
| Apr 24, 1:17 PM CDT | Severe Thunderstorm Watch | SPC | Autauga, Baldwin, Barbour, Bullock, Butler, Choctaw and 23 more | 8 hr |
| Apr 24, 1:22 PM CDT | Mesoscale Discussion | SPC | Blount, Calhoun, Cherokee, Clay, Cleburne, Colbert and 22 more | 113 min |
| Apr 24, 3:40 PM CDT | Mesoscale Discussion | SPC | Autauga, Barbour, Bullock, Butler, Clarke, Coffee and 19 more | 95 min |
| Apr 24, 4:52 PM CDT | Severe Thunderstorm Watch | SPC | Bibb, Blount, Calhoun, Chambers, Cherokee, Chilton and 15 more | 4 hr |
| Apr 24, 6:13 PM CDT | Mesoscale Discussion | SPC | Calhoun, Chambers, Cherokee, Clay, Cleburne, Coosa and 6 more | 2 hr |
| Apr 24, 9:10 AM CDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Ben Hill, Berrien, Brantley and 24 more | 95 min |
| Apr 24, 9:35 AM CDT | Tornado Watch | SPC | Appling, Atkinson, Bacon, Brantley, Bryan, Camden and 15 more | 7 hr |
| Apr 24, 11:05 AM CDT | Mesoscale Discussion | SPC | Atkinson, Berrien, Brooks, Clinch, Colquitt, Cook and 10 more | 85 min |
| Apr 24, 3:00 PM CDT | Severe Thunderstorm Watch | SPC | Baker, Berrien, Brooks, Calhoun, Chattahoochee, Clay and 30 more | 6 hr |
| Apr 24, 3:35 PM CDT | Mesoscale Discussion | SPC | Camden, Charlton | 85 min |
| Apr 24, 6:47 PM CDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Berrien, Brantley, Bryan and 12 more | 118 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.