MESOSCALE DISCUSSION 0525
   NWS STORM PREDICTION CENTER NORMAN OK
   0244 PM CDT SAT APR 21 2007
   
   AREAS AFFECTED...ERN CO...WRN KS...TX/OK PNHDLS...ERN NM/WRN TX
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 211944Z - 212115Z
   
   TSTMS ARE EXPECTED TO FORM AND INCREASE ACROSS THE HIGH PLAINS OF
   ERN NM/ERN CO OVER THE NEXT FEW HOURS. THIS ACTIVITY WILL THEN
   DEVELOP EAST AND INTO AN INCREASINGLY FAVORABLE ENVIRONMENT FOR
   HIGH-BASED SUPERCELLS...AND POSSIBLY TORNADOES. WATCHES WILL BE
   ISSUED SHORTLY FOR PARTS OF ERN NM/CO...EWD INTO PORTIONS OF WRN
   TX/OK/KS.
   
   WATER VAPOR IMAGERY CONTINUES TO DEPICT A COMPACT BUT POTENT IMPULSE
   PROGRESSING EWD ACROSS SWRN NM THIS AFTERNOON. STRONG DPVA AHEAD OF
   THE VORT CENTER HAS ALLOWED THE DRYLINE TO SHARPEN ACROSS ERN NM AS
   LEE-SIDE CYCLONE CONSOLIDATES OVER SERN CO. STRONG AND DEEP-LAYER
   SWLY FLOW WITH 70KT AT 500MB WILL PROMOTE RAPID EWD MIXING OF THE
   DRYLINE ACROSS ERN NM AND TO THE CO/KS BORDER THROUGH 21Z. WHILE AIR
   MASS AHEAD OF THE DRY LINE REMAINS CAPPED...STRONG LARGE SCALE
   ASCENT AND DEEPER BOUNDARY LAYER MIXING IN THE WAKE OF LOW CLOUD
   FIELD NOW MOVING AWAY/ERODING OVER THE TX/OK PNHDLS AND WRN
   KS...WILL RESULT IN RAPID DECREASE IN INHIBITION.
   
   CAPPING HAS AIDED LOW LEVEL MOISTURE RETURN TO THE HIGH PLAINS AND
   LOW CLOUDS/LIMITED MIXING APPEAR TO HAVE MAINTAINED BACKED LOW LEVEL
   FLOW AND ENHANCED CONFLUENCE AHEAD OF THE DRYLINE. LATEST GUIDANCE
   IS CONSISTENT WITH EARLIER THINKING THAT RAPID TSTM DEVELOPMENT WILL
   OCCUR IN A N-S CORRIDOR COINCIDENT WITH THE DRYLINE AND LEADING EDGE
   OF STRONGER LARGE SCALE FORCING...FROM ERN CO INTO ERN NM AROUND
   21Z. INITIALLY...DEEPENING BOUNDARY LAYER AND LIMITED MOISTURE
   SHOULD PROMOTE HIGH-BASED ROTATING STORMS CAPABLE OF LARGE HAIL AND
   LOCALLY DAMAGING DOWNBURST WINDS. A TORNADO OR TWO WILL ALSO BE
   POSSIBLE WHERE LOW LEVEL SHEAR AND BOUNDARY LAYER MOISTURE ARE MORE
   FOCUSED...PERHAPS NEAR THE LEE LOW. ACTIVITY WILL DEVELOP EAST
   THROUGH EARLY EVENING WHERE LOWER LFC AND GREATER LOW LEVEL SHEAR IN
   THE UPDRAFT LAYER ARE EXPECTED TO SUPPORT LONGER-LIVED MESOCYCLONES
   AND TORNADOES...IN ADDITION TO A CONTINUING THREAT OF LARGE HAIL.
   
   ..CARBIN.. 04/21/2007
   
   
   ATTN...WFO...DDC...GLD...LUB...AMA...MAF...PUB...BOU...ABQ...
   
   37480335 38240356 38720393 39350358 39960165 37100172
   34950178 33660245 33290357 33760386