MESOSCALE DISCUSSION 0062
   NWS STORM PREDICTION CENTER NORMAN OK
   1129 PM CST MON JAN 31 2011
   
   AREAS AFFECTED...PORTIONS W-CENTRAL/SW TX THROUGH N-CENTRAL
   TX...PORTIONS S-CENTRAL/SERN OK.
   
   CONCERNING...WINTER MIXED PRECIPITATION 
   
   VALID 010529Z - 011030Z
   
   NWRN PORTIONS OF PRECIP BAND...FROM W-CENTRAL TX NEWD ACROSS
   PORTIONS N-CENTRAL TX...SHOULD EXPERIENCE TRANSITION FROM RAIN TO
   FREEZING RAIN AND SLEET AS SFC FREEZING LINE MOVES SWD BENEATH
   ACTIVITY...WITH LIQUID EQUIVALENT RATES COMMONLY .25 INCH/HOUR AND
   BRIEF/ISOLATED RATES .5 INCH/HOUR.  EMBEDDED TSTMS ALSO MAY PRODUCE
   ISOLATED SVR HAIL.  PRECIP ACROSS WRN PORTIONS OF AREA SHOULD CHANGE
   TO SNOW AFTER ABOUT 06Z WITH SPORADIC 1 INCH/HOUR RATES POSSIBLE.
   
   05Z SFC ANALYSIS INDICATED FREEZING LINE NEAR ADM...20 NNW MWL...40
   NW SJT...15 S MAF...AND EXPECTED TO CONTINUE MOVING SWD FROM
   COMBINATION OF POSTFRONTAL CAA...DIABATIC SFC COOLING AND WET-BULB
   EFFECTS.  PRECIP BAND INITIALLY EXTENDING FROM CROCKETT COUNTY NEWD
   TO MONTAGUE/COOKE COUNTIES IS FCST TO TRANSLATE EWD ACROSS EDWARDS
   PLATEAU...WRN/NRN HILL COUNTRY AND N-CENTRAL TX...BUT AT SLOWER PACE
   THAN SEWD SHIFT OF SFC FREEZING LINE.  THIS EWD SHIFT OF PRECIP
   SHOULD COINCIDE WELL WITH THAT OF MAX IN 700-850 MB LAYER
   FRONTOGENESIS...IMPINGING UPON REGIME OF MOIST ADVECTION/TRANSPORT
   ACCOMPANYING BROAD/30-35 KT LLJ.  ELEVATED MUCAPE 250-700 J/KG IS
   EXPECTED JUST E OF MAIN CONVECTIVE BAND...WITH 40-55 KT EFFECTIVE
   SHEAR SUPPORTING SOME ROTATION ALOFT IN RELATIVELY DISCRETE
   CELLS...AND RELATED ENHANCEMENT TO MIDLEVEL UPDRAFT STRENGTH AND
   HAIL GENERATION POTENTIAL.
   
   MEANWHILE...FREEZING RAIN IS LIKELY IN REAR PORTION OF CONVECTIVE
   PLUME...THEN TRANSITION TO SLEET AND SNOW IN WWD/NWWD
   CROSS-SECTION...AS SUPERFREEZING LAYER ABOVE FRONTAL SURFACE BECOMES
   MORE VERTICALLY COMPRESSED AND WEAKER IN MAGNITUDE.  RAIN MAY CHANGE
   STRAIGHT TO SNOW AFTER 06Z ACROSS PERMIAN BASIN REGION...AS
   CONTINUED DEEPENING OF POSTFRONTAL BOUNDARY LAYER COINCIDES WITH
   COOLING OF COLUMN ALOFT...AND LARGE-SCALE DCVA/ASCENT AHEAD OF
   STG/APCHG SHORTWAVE TROUGH.
   
   ..EDWARDS.. 02/01/2011
   
   
   ATTN...WFO...TSA...FWD...OUN...SJT...LUB...MAF...
   
   LAT...LON   32669704 31589896 30730036 30890212 31920177 33080011
               33019971 33189866 33649769 34329672 34209587 32669704