MESOSCALE DISCUSSION 1201
   NWS STORM PREDICTION CENTER NORMAN OK
   0915 AM CDT THU JUN 18 2009
   
   AREAS AFFECTED...S-CNTRL KY SSEWD THROUGH MIDDLE/ERN TN INTO
   PORTIONS OF GA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 181415Z - 181545Z
   
   BOWING MCS OVER SRN IND AS OF 14Z IS EXPECTED TO CONTINUE SEWD AND
   EVENTUALLY MORE SWD INTO GA TODAY.  AN ADDITIONAL...DOWNSTREAM WW
   WILL BE REQUIRED.  PARTS OF AREA WILL BE UPGRADED TO MODERATE RISK
   AT 1630Z FOR THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS.
   
   MCS OVER SRN IND HAS ACCELERATED TO 50-55 KT OVER THE PAST HALF HOUR
   OR SO OVER SRN IN WITH EXTRAPOLATED MOTION TAKING IT INTO NRN GA BY
   19Z.  12Z BNA SOUNDING IS LIKELY REPRESENTATIVE OF AMBIENT INFLOW
   AIR MASS...FEATURING A MOIST BOUNDARY LAYER AND STEEP MIDLEVEL LAPSE
   RATES...CONTRIBUTING TO A POTENTIALLY STRONGLY UNSTABLE AIR MASS. 
   THIS INSTABILITY IN CONJUNCTION WITH MODERATELY STRONG NWLY WINDS
   /40-50 KT/ IN THE MIDLEVELS SHOULD EFFECTIVELY MAINTAIN THE BOWING
   STRUCTURE AS IT PROGRESSES SEWD TODAY.
   
   ..MEAD.. 06/18/2009
   
   
   ATTN...WFO...GSP...MRX...JKL...FFC...LMK...OHX...HUN...
   
   LAT...LON   36238657 36918651 37438599 37398522 36578424 35348341
               34528329 33948364 33888456 34398537 35648637 36238657