MESOSCALE DISCUSSION 0531
   NWS STORM PREDICTION CENTER NORMAN OK
   0727 PM CDT SUN APR 19 2009
   
   AREAS AFFECTED...NRN AL AND SRN MIDDLE TN
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 174...
   
   VALID 200027Z - 200130Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 174
   CONTINUES.
   
   PRIMARY SEVERE THREAT IS EXPECTED TO REMAIN OVER SERN PARTS OF WW
   174. 
   
   STORMS THAT DEVELOPED WITHIN PRE-FRONTAL CONVERGENCE ZONE CONTINUE
   EWD THROUGH NRN AL FROM NEAR HUNTSVILLE SWWD TO NEAR FAYETTE. THESE
   STORMS REMAIN ON THE NOSE OF A 45-50 KT SLY LOW LEVEL JET THAT WILL
   MAINTAIN STRONG STORM RELATIVE INFLOW AND HELP SUSTAIN ACTIVITY NEXT
   COUPLE HOURS. HOWEVER...STORMS WILL BEGIN TO APPROACH ERN EDGE OF
   INSTABILITY AXIS AS THEY CONTINUE EAST TOWARD NW GA. ISOLATED LARGE
   HAIL...DAMAGING WIND AND PERHAPS A TORNADO OR TWO WILL REMAIN
   POSSIBLE THROUGH THE EARLY EVENING.
   
   SEVERE THREAT APPEARS MORE MARGINAL ACROSS REMAINING PARTS OF WW 174
   INCLUDING SRN MIDDLE TN WHERE RADAR DATA SHOWS A BAND OF WEAK
   CONVECTION THAT HAS DEVELOPED WITHIN ZONE OF MID-LEVEL ASCENT AHEAD
   OF EWD ADVANCING VORT MAX. WEAK INSTABILITY WILL LIKELY REMAIN THE
   PRIMARY LIMITING FACTOR IN THIS REGION.
   
   ..DIAL.. 04/20/2009
   
   
   ATTN...WFO...BMX...HUN...
   
   LAT...LON   34458560 33668684 33828760 34878673 34458560