Mesoscale Discussion 428

Issued

Apr 24, 2021, 6:13 PM CDT (23:13 UTC)

Expired

Apr 24, 2021, 8:15 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe thunderstorm watch 110

The Atlanta radar (KFFC), 66 km from the middle of the area, began a volume at 23:14 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.

659 
ACUS11 KWNS 242313
SWOMCD
SPC MCD 242313 
GAZ000-ALZ000-250115-

Mesoscale Discussion 0428
NWS Storm Prediction Center Norman OK
0613 PM CDT Sat Apr 24 2021

Areas affected...Northeast Alabama and northwest Georgia

Concerning...Severe Thunderstorm Watch 110...

Valid 242313Z - 250115Z

The severe weather threat for Severe Thunderstorm Watch 110
continues.

SUMMARY...Thunderstorms across northeast Alabama and northwest
Georgia will continue to pose a risk for severe hail and wind
through the evening hours.

DISCUSSION...Discrete and embedded supercells continue to traverse
eastward across northeast AL in the vicinity of a surface low and
along a weak trough axis. Several severe hail reports have been
noted with this activity, and and an environment featuring 1000-1500
J/kg MLCAPE along with 50-60 knots of effective bulk shear will
remain supportive of a severe hail threat for the next couple of
hours. Deep-layer shear vectors oriented along the trough axis may
favor eventual upscale growth that could limit the hail threat while
augmenting the potential for damaging winds, though the exact
evolution is uncertain. 

However, the environment remains somewhat spatially limited with
eastward extent due to cooler air to the north of a weak warm front,
and a residual cold pool in place across central GA. Modest warm air
advection in the 925-850 mb layer across northwest GA may allow for
some eastward expansion of the viable warm sector, but the general
expectation is for storms to gradually weaken as they move into
north-central GA later this evening.

..Moore.. 04/24/2021

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

ATTN...WFO...FFC...BMX...HUN...

LAT...LON   33198699 33978625 34378583 34698526 34858481 34638428
            34428375 34048351 33698345 33348360 33038415 32878484
            32748544 32768603 32838651 32988681 33198699

Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Alabama, 2021Every mesoscale discussion in 2021

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.