MESOSCALE DISCUSSION 0432
   NWS STORM PREDICTION CENTER NORMAN OK
   1111 PM CDT THU APR 14 2011
   
   AREAS AFFECTED...CNTRL/WRN AR...EXTREME SWRN MO...ERN OK...EXTREME
   N-CNTRL/NERN TX
   
   CONCERNING...TORNADO WATCH 136...
   
   VALID 150411Z - 150545Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 136 CONTINUES.
   
   CONVECTION ACROSS E-CNTRL/SERN OK AND N-CNTRL TX IS EVOLVING TOWARD
   A MORE LINEAR MODE...AS INCREASING DEEP-LAYER ASCENT PROMOTES
   GREATER STORM COVERAGE AHEAD OF AN APPROACHING COLD FRONT/DRYLINE
   HYBRID. MERGING COLD POOLS WILL CONTINUE TO ALLOW THIS EVOLUTION
   TOWARD A QLCS TO CONTINUE...ESPECIALLY NEAR AND SOUTH OF A MESOLOW
   ANALYZED AROUND FORT SMITH AT 03Z. GIVEN EFFECTIVE BULK SHEAR
   VECTORS ORTHOGONAL TO THE LEADING CONVECTIVE LINE WITH MAGNITUDES OF
   50 TO 60 KT...THE COLD POOL CIRCULATION WILL INTERACT CONSTRUCTIVELY
   WITH THE DEEP-LAYER SHEAR TO PROMOTE STRONG SLAB-LIKE ASCENT AT THE
   LEADING EDGE OF THE COLD POOL. THIS WILL PROMOTE A
   FORWARD-PROPAGATING MCS ACROSS AR THROUGH THE OVERNIGHT HOURS...AS
   AFFIRMED BY RECENT WRF-NMM AND EXPERIMENTAL HRRR GUIDANCE. 
   
   DAMAGING WINDS /INCLUDING GUSTS TO 70 KT/ AND LARGE HAIL /SOME
   POTENTIALLY SIGNIFICANT/ WILL REMAIN A CONCERN GIVEN MLCAPE VALUES
   OF 1000 TO 1500 J/KG ACROSS CNTRL/SRN AR. THIS MODERATE INSTABILITY
   WILL BE MAINTAINED BY AN INFLUX OF GULF MOISTURE /DEWPOINTS IN THE
   LOWER 60S/ SOUTH OF A DEVELOPING WEAK WARM FRONT EXTENDING SE OF THE
   MESOLOW. ASCENT INVOF THIS BOUNDARY COULD YIELD A FEW SUPERCELLULAR
   STRUCTURES LEADING THE MCS ACROSS CNTRL AR. WHILE THE TORNADO THREAT
   WILL PERSIST THROUGH THE NIGHT DUE TO A STRENGTHENING LOW-LEVEL JET
   SUPPORTING EFFECTIVE SRH VALUES AOA 300 M2/S2...THE GREATEST THREAT
   WILL OCCUR NEAR THE MESOLOW AND THE WARM FRONT. EMBEDDED
   SUPERCELLULAR STRUCTURES AND MESOVORTICES IN THE QLCS WILL ALSO HAVE
   A INCREASED PROPENSITY FOR BRIEF TORNADO PRODUCTION.
   
   ..COHEN.. 04/15/2011
   
   
   ATTN...WFO...LZK...SGF...SHV...TSA...FWD...OUN...
   
   LAT...LON   33489650 34489546 35419515 36359519 36909464 36999326
               36579212 35849171 33629254 33179431 33219637 33489650