MESOSCALE DISCUSSION 0648
   NWS STORM PREDICTION CENTER NORMAN OK
   0238 PM CDT WED MAY 02 2007
   
   AREAS AFFECTED...N CNTRL TX+
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 021938Z - 022145Z
   
   TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT ACROSS
   NORTH CENTRAL TEXAS LATE THIS AFTERNOON.  POTENTIAL SEEMS A BIT
   MARGINAL...BUT A WW COULD STILL BECOME NECESSARY TOWARD 21-22Z. 
   LOCALLY HEAVY RAINFALL MAY BE THE PRIMARY THREAT WITH LARGE CLUSTER
   OF STORMS LIKELY TO AFFECT AT LEAST PARTS OF THE DALLAS/FORT WORTH
   METROPLEX DURING THE EVENING RUSH HOUR.
   
   AREA OF STRONGER LOWER/MID TROPOSPHERIC WARM ADVECTION...PERHAPS
   ASSOCIATED WITH A LEAD IMPULSE PROGRESSING OUT OF SOUTHERN BRANCH
   TROUGH...APPEARS TO HAVE PROVIDED SUPPORT FOR MESOSCALE CONVECTIVE
   SYSTEM WHICH HAS EVOLVED OVER WEST CENTRAL TEXAS.  MODELS ARE
   SUGGESTIVE THAT THIS FORCING WILL SPREAD TOWARD NORTH CENTRAL TEXAS
   AND WEAKEN LATE THIS AFTERNOON.  THE BOUNDARY LAYER AHEAD OF
   ACTIVITY ACROSS NORTH CENTRAL TEXAS IS MOIST AND BECOMING MODERATELY
   UNSTABLE....WITH MIXED LAYER CAPE NOW ON THE ORDER OF 1000-2000
   J/KG.  THIS COULD MAINTAIN VIGOROUS CONVECTIVE
   DEVELOPMENT...SUPPORTED BY FORCING ALONG LEADING EDGE OF SURFACE
   COLD POOL GENERATED BY ONGOING CONVECTION.  AND...ACTIVITY MAY
   APPROACH THE DALLAS/FORT WORTH METROPLEX DURING THE 02/22-03/00Z
   TIME FRAME.  THERMODYNAMIC PROFILES APPEAR UNSATURATED ENOUGH TO
   MAINTAIN SIGNIFICANT EVAPORATIVE COOLING NEAR HEAVY RAIN CORES...
   CONTRIBUTING TO RISK FOR ISOLATED DOWNBURSTS...IN ADDITION TO LARGE
   HAIL.  BUT...A RELATIVELY WEAK DEEP LAYER WESTERLY MEAN FLOW
   REGIME...ON THE ORDER OF 20 KTS...WILL TEND TO MITIGATE RISK FOR A
   BROADER SCALE DAMAGING WIND EVENT.
   
   ..KERR.. 05/02/2007
   
   
   ATTN...WFO...FWD...
   
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