MESOSCALE DISCUSSION 1590
   NWS STORM PREDICTION CENTER NORMAN OK
   1218 PM CDT TUE JUL 12 2011
   
   AREAS AFFECTED...EAST-CENTRAL KY AND MIDDLE/EASTERN TN
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 121718Z - 121845Z
   
   ISOLATED DOWNBURSTS AND LOCALLY HEAVY RAINFALL WITH RATES IN EXCESS
   OF 1 IN/HR WILL BE POSSIBLE THROUGH THE AFTERNOON ACROSS
   EAST-CENTRAL/MIDDLE PORTIONS OF TN/KY. A SEVERE TSTM WATCH IS NOT
   EXPECTED AT THIS TIME.
   
   ON THE WESTERN PERIPHERY OF A DECAYING EARLY DAY TSTM COMPLEX...A
   WESTWARD PROPAGATING OUTFLOW BOUNDARY CONTINUES TO SUPPORT
   QUASI-FOCUSED UPLIFT/CONVECTIVE REGENERATION ACROSS EAST-CENTRAL
   PORTIONS OF KY/TN EARLY THIS AFTERNOON. ADDITIONAL
   DESTABILIZATION/BOUNDARY PROPAGATION INTO A VERY MOIST/UNSTABLE
   AIRMASS SHOULD CONTINUE TO YIELD ISOLATED STRONG/SEVERE TSTMS...WITH
   MLCAPE NOW ESTIMATED TO BE ON THE ORDER OF 3000-4000 J/KG AMID
   NEGLIGIBLE CINH. A PARTICULARLY ORGANIZED/SUSTAINED SEVERE THREAT IS
   NOT EXPECTED OWING TO WEAK VERTICAL SHEAR AS NOTED BY REGIONAL
   WSR-88D VWPS. HOWEVER...THE COMBINATION OF STRONG INSTABILITY/STEEP
   LAPSE RATES WILL SUPPORT MICROBURST POTENTIAL...WHILE ALSO YIELDING
   LOCALLY HEAVY RAINFALL GIVEN THE WESTWARD PROPAGATING OUTFLOW
   BOUNDARY AND WEAK SOUTHEASTERLY MEAN FLOW.
   
   ..GUYER.. 07/12/2011
   
   
   ATTN...WFO...MRX...JKL...ILN...LMK...OHX...HUN...PAH...
   
   LAT...LON   35118743 35948746 37868665 38448392 36658480 35158573
               35118743