ACUS11 KWNS 211931
SWOMCD
SPC MCD 211931=20
SCZ000-NCZ000-TNZ000-VAZ000-KYZ000-GAZ000-212130-

Mesoscale Discussion 0283
NWS Storm Prediction Center Norman OK
0231 PM CDT Sat Mar 21 2026

Areas affected...the Southern Appalachians into the Carolinas

Concerning...Severe potential...Watch unlikely=20

Valid 211931Z - 212130Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated to widely scattered thunderstorms may pose a
threat for occasional damaging wind gusts and marginally severe hail
this afternoon/evening. Watch issuance is unlikely.

DISCUSSION...Latest regional surface analysis depicts surface
dewpoints in the upper-40s to low-50s F amid deep, well-mixed
boundary layer profiles. Despite this limited low-level moisture,
cool temperatures and steep lapse rates in the mid-levels are
helping to support weak buoyancy, with latest mesoanalysis
indicating the presence of 500-750 J/kg MLCAPE across portions of
Middle and eastern Tennessee. As modest ascent increases ahead of an approaching mid-level trough and convective temperatures are reached
over the next few hours, isolated to widely scattered thunderstorm
development is expected across the southern Cumberland and Blue
Ridge Mountains. While mid/upper level flow will remain weak to
modest (effective bulk shear of only 25-30 kts), some limited storm organization is possible. Marginally severe hail may accompany the
strongest cores amid an initially cellular storm mode. With time, a
gradual evolution toward a more linear/line segment mode is then
expected as storms move east-southeastward. Steep low-level lapse
rates (8.5+ C/km) and DCAPE of 600-900 J/kg (locally higher) will
support the potential for isolated strong to damaging wind gusts.
The onset of nocturnal boundary-layer stabilization should then
result in a decreasing severe threat later this evening as the
storms move into the coastal Carolinas.

..Chalmers/Leitman.. 03/21/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7cj5ltOqH_GIInwr1LiTkqwJ4mVvMtyAM3KYHMmih2XUKY6y3AWx-2aM8FEVW0oNi6M7AwOdN= E2CQzVf0G6San3DobU$ for graphic product...

ATTN...WFO...RNK...CAE...GSP...MRX...JKL...FFC...

LAT...LON 35508468 35828467 36248453 36568421 36708366 36668308
36168178 35828091 35608060 35278052 34838053 34418075
34138143 34408249 34988395 35198450 35508468=20

MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


=3D =3D =3D
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