MESOSCALE DISCUSSION 0285
   NWS STORM PREDICTION CENTER NORMAN OK
   0928 AM CST WED MAR 19 2003
   
   AREAS AFFECTED...ERN TN...NRN AL...CNTRL/ERN KY
   
   CONCERNING...TORNADO WATCH 56...
   
   VALID 191528Z - 191730Z
   
   CENTRAL/EASTERN KENTUCKY IS BEING MONITORED FOR POSSIBILITY OF
   NEW WW BY EARLY AFTERNOON.
   
   LINE OF INTENSE THUNDERSTORMS CONTINUES TO DEVELOP ACROSS THE
   TENNESSEE VALLEY...SUPPORTED BY STRONG FORCING FOR UPWARD
   VERTICAL MOTION AHEAD OF MID-LEVEL SHORT WAVE TROUGH.  MID-LEVEL
   TROUGH IS ROTATING ACROSS THE TENNESSEE VALLEY...AROUND EASTERN
   PERIPHERY OF CLOSED UPPER LOW CURRENTLY REDEVELOPING
   NORTHEASTWARD INTO THE OZARKS.	OCCLUDED SURFACE FRONT IS
   PROVIDING FOCUS FOR CONVECTIVE DEVELOPMENT...WITH LIFTED PARCELS
   LIKELY STILL IN NARROW BAND OF STRONGER WARM ADVECTION ABOVE
   BOUNDARY LAYER.  HOWEVER... SUFFICIENT HEATING OF BOUNDARY LAYER
   WILL TAKE PLACE ACROSS EASTERN TENNESSEE NEXT FEW HOURS TO
   SUPPORT CONTINUING THREAT FOR SURFACE-BASED STORMS WITH POTENTIAL
   FOR ISOLATED TORNADOES AND DAMAGING WIND GUSTS IN ENVIRONMENT
   WITH VERY LARGE LOW-LEVEL HODOGRAPHS BENEATH STRONG AND
   STRENGTHENING MID/UPPER JET.
   
   UPPER JET AXIS IS PROVIDING SOUTHERN LIMIT TO DEEP CONVECTIVE
   DEVELOPMENT...CURRENTLY NEAR THE BIRMINGHAM AL AREA...THIS
   APPEARS LIKELY TO REMAIN THE CASE INTO THE EARLY AFTERNOON HOURS.
    AS SHORT WAVE TROUGH CONTINUES TO PIVOT NORTHWARD INTO THE OHIO
   VALLEY...STRONGER FORCING WILL SUPPORT NORTHWARD DEVELOPMENT OF
   ACTIVITY INTO PARTS OF CENTRAL AND EASTERN KENTUCKY...WHERE
   DESTABILIZATION MAY BECOME SUFFICIENT TO SUPPORT SUPERCELL
   POTENTIAL BY 18-20Z TIME FRAME.
   
   ..KERR.. 03/19/2003
   
   
   ATTN...WFO...MRX...JKL...FFC...LMK...OHX...BMX...
   
   36798597 37408579 37938542 37818401 37168309 36138310
   35218450 34598553 34048615 33938681 35188653