MD 2255 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHEAST GA…WESTERN/CENTRAL SC…AND SOUTHWEST/SOUTH-CENTRAL NC
Mesoscale Discussion 2255
NWS Storm Prediction Center Norman OK
0145 PM CDT Fri Oct 20 2023
Areas affected…Northeast GA…western/central SC…and
southwest/south-central NC
Concerning…Severe potential…Watch unlikely
Valid 201845Z – 202115Z
Probability of Watch Issuance…20 percent
SUMMARY…Thunderstorms should gradually increase in coverage and
intensity through the afternoon. Isolated strong to severe gusts and
marginal hail are possible. A watch is not expected.
DISCUSSION…During the next few hours, increasing thunderstorm
development is expected along/east of the southern Appalachians, as
a cold front continues east-southeastward into the area. This
activity will be aided by strengthening upper-level divergence in
the left exit region of a robust mid/upper-level jet crossing the
OH/TN Valleys. While pre-convective instability will remain
marginal, boundary-layer heating/mixing in the wake of earlier
convection, coupled with steepening low/mid-level lapse rates, will
yield sufficient instability for isolated to widely scattered
low-topped thunderstorms. Strengthening mid/upper-level westerlies
associated with the approaching jet max will contribute to 30-45 kt
of effective shear — characterized by a mostly straight hodograph.
As a result, several loosely organized clusters/line segments and
perhaps transient low-topped supercell structures are possible
through the afternoon. Strong to locally severe gusts (50-60 mph)
and marginal hail (up to 1 inch diameter) could accompany the
more-organized storms. However, the weak instability and veered
pre-frontal low-level winds should generally limit storm intensity,
and a watch is not currently expected.
..Weinman/Guyer.. 10/20/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…RAH…CAE…GSP…FFC…
LAT…LON 34158329 34618302 35408200 35798117 35818075 35618025
35128023 34828030 34428046 33868101 33498162 33338226
33308285 33418320 33748334 34158329
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