Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 298
The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2021, 9:14 AM CDT for 12 counties in Alabama; 11 counties in Georgia. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Mar 28, 2021, 9:14 AM CDT (14:14 UTC)
- Expired
- Mar 28, 2021, 10:15 AM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 67
All 23 counties
Autauga County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Lowndes County, AL, Marengo County, AL, Randolph County, AL, Tallapoosa County, AL, Wilcox County, AL, Carroll County, GA, Cherokee County, GA, Cobb County, GA, Coweta County, GA, DeKalb County, GA, Douglas County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA, Heard County, GA, Paulding County, GA
The radar
The Maxwell AFB radar (KMXX), 56 km from the middle of the area, began a volume at 14:15 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
Birmingham, AL (KBMX), launched 12:00Z, 2.2 hours before the alert went out and 71 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
- 757 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 650 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 326 m²/s²
- 0-3 km storm-relative helicity
- 355 m²/s²
- Significant tornado parameter
- 1.6
- Supercell composite
- 9.1
The text
As transmitted.
566
ACUS11 KWNS 281414
SWOMCD
SPC MCD 281414
GAZ000-ALZ000-281515-
Mesoscale Discussion 0298
NWS Storm Prediction Center Norman OK
0914 AM CDT Sun Mar 28 2021
Areas affected...Portions of central AL into west-central GA
Concerning...Severe Thunderstorm Watch 67...
Valid 281414Z - 281515Z
The severe weather threat for Severe Thunderstorm Watch 67
continues.
SUMMARY...An isolated strong/gusty wind threat continues in the
short term. Downstream Severe Thunderstorm Watch issuance is not
expected.
DISCUSSION...Outflow has generally surged well ahead of a line of
storms extending along a cold front from central AL into
west-central and northern GA. VWPs from KMXX and KFFC ahead of the
line still show strong west-southwesterly flow in low/mid levels.
Isolated strong wind gusts should remain possible for another hour
or two given this enhanced boundary-layer flow. However, the
thermodynamic environment appears only marginally conducive for
maintaining robust updrafts, as instability generally decreases
ahead of the line. Current expectations are for this line of storms
to remain mostly sub-severe through the morning hours, and
downstream watch issuance is not expected at this time.
..Gleason.. 03/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FFC...BMX...MOB...
LAT...LON 32118805 32888678 33558547 34148473 34498405 34118385
33358468 32438610 31868694 31818792 32118805SPC 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, 7:29 AM CDT | Mesoscale Discussion | SPC | Calhoun, Cleburne, Talladega | 91 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 Alabama, 2021Mesoscale Discussions in Georgia, 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.