609
ACUS11 KWNS 211931
SWOMCD
SPC MCD 211931
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
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 WWW.SPC.NOAA.GOV 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
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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