MESOSCALE DISCUSSION 0470
   NWS STORM PREDICTION CENTER NORMAN OK
   0113 AM CDT WED MAR 19 2008
   
   AREAS AFFECTED...PARTS OF WRN/MIDDLE TN INTO WRN/CNTRL KY
   
   CONCERNING...TORNADO WATCH 132...
   
   VALID 190613Z - 190715Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 132 CONTINUES.
   
   BUT...THE SEVERE THREAT IS EXPECTED TO GRADUALLY BECOME MORE
   ISOLATED.  AND...AN ADDITIONAL WW TO THE EAST/NORTHEAST OF WW 132 IS
   NOT ANTICIPATED.
   
   NARROW BAND OF STRONGER CONVECTIVE ACTIVITY...NOW DEVELOPING RAPIDLY
   NORTHEASTWARD TO THE SOUTH/EAST OF THE CONFLUENCE OF THE MISSISSIPPI
   AND OHIO RIVERS...APPEARS TO BE COINCIDENT WITH A WEAK MID-LEVEL
   IMPULSE/SURFACE FRONTAL WAVE AND ASSOCIATED LOW-LEVEL JET CORE
   SHIFTING OUT OF SOUTHERN BRANCH TROUGH INTO CONFLUENT FLOW REGIME
   ACROSS THE OHIO VALLEY.  CONVECTION IS SPREADING INTO AN ENVIRONMENT
   WITH PROGRESSIVELY STABLE MID-LEVEL LAPSE RATES...AND IT IS
   QUESTIONABLE WHETHER DESTABILIZATION...EVEN WITH LOW-LEVEL MOISTURE
   ADVECTION AHEAD OF LINE...WILL BE SUFFICIENT TO MAINTAIN CLOUD
   ELECTRIFICATION.  
   
   HOWEVER...CONVECTION WILL PROBABLY CONTINUE ACROSS THE INTERSTATE 65
   CORRIDOR...NORTH OF NASHVILLE INTO THE LOUISVILLE AREA BETWEEN NOW
   AND 09-10Z.  AND...SUB CLOUD BASE TEMPERATURE DEW POINT SPREADS MAY
   BE LARGE ENOUGH TO SUPPORT SUFFICIENT EVAPORATIVE COOLING TO MIX
   DOWN STRONGER MOMENTUM...NEAR 50-60+ KT SOUTHWESTERLY LOW-LEVEL
   JET...TO THE SURFACE.  THUS...RISK OF SPORADIC DAMAGING WIND GUSTS
   MAY CONTINUE TO THE EAST NORTHEAST OF EXPIRING WATCH AT LEAST
   ANOTHER SEVERAL HOURS.
   
   ..KERR.. 03/19/2008
   
   
   ATTN...WFO...LMK...OHX...PAH...MEG...
   
   36518862 37248770 37958589 38048549 37688512 36728569
   36388610 36028691 35678756 35218857 35048923 35158947
   35878895