SPC MESOSCALE DISCUSSION 0599 FOR MUCH OF MO...NRN AR...WRN
   TN...CNTRL/SRN IL AND WRN KY
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
   
   VALID 011413Z - 011600Z
   
   ELEVATED STORMS ARE EXPECTED TO GRADUALLY INCREASE IN COVERAGE AND
   INTENSITY OVER THE NEXT FEW HOURS. LARGE HAIL SHOULD BE THE PRIMARY
   THREAT. AREA WILL CONTINUE TO BE MONITORED AND A WW MAY BE REQUIRED
   IF CURRENT TRENDS CONTINUE.
   
   LATEST SURFACE ANALYSIS SHOWS A WEAKENING WARM FRONT EXTENDS EWD
   THROUGH NRN AR FROM A SURFACE LOW IN SRN KS. FARTHER N THE PRIMARY
   WARM FRONT EXTENDS FROM THE SURFACE LOW IN SRN KS EWD THROUGH CNTRL
   MO AND SRN IL. ATMOSPHERE TO THE SW OF THESE BOUNDARIES IS QUITE
   UNSTABLE WITH THE 12Z SPRINGFIELD SOUNDING SHOWING 3000 J/KG OF
   MUCAPE AND 7-5KM LAPSE RATES. HOWEVER...MUCH OF THIS INSTABILITY
   WAS CAPPED AND STORMS CURRENTLY DEVELOPING ARE LIKELY ROOTED WELL
   ABOVE THE BOUNDARY LAYER. WARM ADVECTION/ISENTROPIC LIFT
   ACCOMPANYING A SWLY 40 KT LOW LEVEL JET WILL CONTINUE TO SUPPORT
   ELEVATED CONVECTIVE DEVELOPMENT ALONG AND N OF THESE BOUNDARIES AND
   CONTRIBUTE TO DESTABILIZATION FARTHER NE WITH TIME. THIS SHOULD
   RESULT IN A GRADUAL INTENSIFICATION OF STORMS WITH LARGE HAIL
   BECOMING LIKELY. ELEVATED MIXED LAYER WILL CONTINUE TO SPREAD EWD
   INTO THE AFTERNOON AND THIS SHOULD SUPPORT SEVERE THREAT GRADUALLY
   SHIFTING EWD INTO IL...WRN KY/WRN TN BY NOON.
   
   ..DIAL.. 05/01/02