MESOSCALE DISCUSSION 0092
   NWS STORM PREDICTION CENTER NORMAN OK
   1013 PM CST SUN FEB 06 2011
   
   AREAS AFFECTED...NRN AND CNTRL AR
   
   CONCERNING...HEAVY SNOW 
   
   VALID 070413Z - 070815Z
   
   HEAVY SNOW APPEARS POSSIBLE ACROSS PARTS OF NORTH CENTRAL ARKANSAS
   OVERNIGHT...NORTHWEST THROUGH NORTHEAST OF LITTLE ROCK ...PERHAPS
   INCLUDING THE LITTLE ROCK AREA.
   
   AN AREA OF ENHANCED MID-LEVEL FORCING FOR UPWARD VERTICAL MOTION
   ...ASSOCIATED WITH AN INITIAL SHORT WAVE IMPULSE LIFTING NORTHEAST
   OF THE ARKLATEX...APPEARS LIKELY TO CONTRIBUTE TO INCREASING
   PRECIPITATION ACROSS MUCH OF NORTHERN AND CENTRAL ARKANSAS DURING
   THE NEXT FEW HOURS.  AS THIS OCCURS...MODELS SUGGEST EVAPORATION
   WILL GRADUALLY SATURATE AND COOL LOW-LEVEL THERMODYNAMIC PROFILES
   TOWARD FREEZING.  COOLING WILL PROBABLY BE ENHANCED BY WEAK COLD
   ADVECTION...AS A WEAK SURFACE LOW MIGRATES EASTWARD NEAR THE
   SOUTHERN ARKANSAS BORDER...AND A CHANGEOVER FROM RAIN TO SNOW AT THE
   SURFACE IS EXPECTED OVERNIGHT.
   
   WITH THE APPROACH OF ANOTHER VIGOROUS IMPULSE...LIFTING OUT OF THE
   BASE OF THE BROADER SCALE UPPER TROUGH OVER TEXAS DURING THE 06-09Z
   TIME FRAME...LATEST RUC GUIDANCE SUGGESTS STRENGTHENING LIFT IN THE
   MIXED PHASE LAYER FAVORABLE FOR LARGE DENDRITIC ICE CRYSTAL GROWTH. 
   IN THE PRESENCE OF PRECIPITABLE WATER IN EXCESS OF 0.5
   INCHES...CONDITIONS SEEM LIKELY TO BECOME SUPPORTIVE OF 1+ INCH PER
   HOUR SNOW RATES BY 09Z...PARTICULARLY WITH CONVECTION POSSIBLE AS
   STEEPENING MID-LEVEL LAPSE RATES CONTRIBUTE TO WEAK DESTABILIZATION.
    SNOW RATES AND TOTALS MAY BE ENHANCED FURTHER BY OROGRAPHIC FORCING
   ACROSS THE BOSTON AND OUACHITA MOUNTAINS.
   
   ..KERR.. 02/07/2011
   
   
   ATTN...WFO...MEG...LZK...
   
   LAT...LON   35179368 36129298 36189141 35999091 35819077 34849213
               34759267 34849335 35179368