MESOSCALE DISCUSSION 1553
   NWS STORM PREDICTION CENTER NORMAN OK
   1225 PM CDT WED AUG 17 2016

   AREAS AFFECTED...FAR ERN KY...MUCH OF WV...WRN MD
   PANHANDLE...PORTIONS OF WRN AND NRN VA

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 171725Z - 171900Z

   PROBABILITY OF WATCH ISSUANCE...60 PERCENT

   SUMMARY...THUNDERSTORMS MAY PRODUCE STRONG/LOCALLY DAMAGING WIND
   GUSTS THIS AFTERNOON. AREA BEING MONITORED FOR POSSIBLE WATCH
   ISSUANCE.

   DISCUSSION...A WEAK UPPER DISTURBANCE AHEAD OF THE MAIN UPPER TROUGH
   IS TRACKING EASTWARD FROM ERN KY INTO WESTERN WV WITH ATTENDANT
   INCREASE IN THUNDERSTORM COVERAGE/INTENSITY OCCURRING OVER THE LAST
   HOUR OR TWO. THE DOWNSTREAM AIRMASS ACROSS MUCH OF WV INTO ADJACENT
   PORTIONS OF VA HAS WARMED INTO THE 80S TO LOW 90S WITH DEWPOINTS IN
   THE UPPER 60S TO LOW 70S...RESULTING IN STRONG INSTABILITY.
   FURTHERMORE...DEEP LAYER EFFECTIVE SHEAR OF 25-35 KT WILL BE
   SUFFICIENT FOR ORGANIZED CELLS WITH MARGINAL SUPERCELL
   CHARACTERISTICS. IN FACT...ONE CELL ENTERING PUTNAM COUNTY WV WAS
   SHOWING BROAD LOW-LEVEL ROTATION AS OF 17Z. 0-1 KM SHEAR WILL REMAIN
   WEAK MITIGATING THE OVERALL TORNADO THREAT...BUT VERTICAL SPEED
   SHEAR COUPLED WITH VERY MODEST LOW-LEVEL DIRECTIONAL SHEAR WILL BE
   SUFFICIENT FOR SOME LOW-LEVEL ROTATION AND A WEAK/BRIEF TORNADO
   CANNOT BE RULED OUT. THE MAIN CONCERN ACROSS THE REGION WILL BE
   DAMAGING WIND GUSTS WITH WIDESPREAD 0-3 KM LAPSE RATES FROM 7-8 DEG
   C/KM AND PW VALUES FROM 1.5-2.0 INCHES INCREASING CHANCES FOR STRONG
   DOWNDRAFTS. THESE DOWNBURST WINDS ARE MAINLY EXPECTED TO OCCUR WITH
   INDIVIDUAL CELLS OR PERHAPS MULTICELL CLUSTERS AS STORM MERGERS AND
   OUTFLOW INTERACTIONS OCCUR. A WATCH MAY BE NEEDED WITHIN THE NEXT
   HOUR OR SO.

   ..LEITMAN/DARROW.. 08/17/2016


   ATTN...WFO...LWX...RNK...PBZ...RLX...MRX...JKL...

   LAT...LON   38618259 38858221 39028182 39388068 39637948 39577885
               39317862 38837863 38267889 37767949 37398028 37208076
               37088168 37098236 37418290 38048294 38618259