MESOSCALE DISCUSSION 0154
   NWS STORM PREDICTION CENTER NORMAN OK
   0344 AM CST TUE FEB 12 2013
   
   AREAS AFFECTED...TX PANHANDLE/WESTERN OK
   
   CONCERNING...HEAVY SNOW 
   
   VALID 120944Z - 121415Z
   
   SUMMARY...MODERATE/HEAVY SNOW WILL BECOME INCREASINGLY PREVALENT
   ACROSS MUCH OF THE TX PANHANDLE INTO WESTERN OK THROUGH THE
   EARLY/MID MORNING HOURS. SNOWFALL RATES WILL REACH/POTENTIALLY
   EXCEED 1 IN/HR THROUGH 12Z-15Z...WITH AS MUCH AS 2 IN/HR LOCALIZED
   RATES POSSIBLE FOR RELATIVELY SHORT DURATIONS.
   
   DISCUSSION...OVERNIGHT WATER VAPOR IMAGERY IS INDICATIVE OF AN
   EAST-NORTHEASTWARD SHIFTING UPPER TROUGH CENTERED OVER SOUTHERN
   NM/FAR SOUTHWEST TX. THE INFLUENCE OF THIS TROUGH...IN CONJUNCTION
   WITH WARM ADVECTION AND INCREASINGLY STRONG UPPER DIVERGENCE VIA A
   STRONG POLAR JET EXIT REGION /100-125 KT AT 300 MB/...WILL
   CONTRIBUTE TO INCREASING PRECIPITATION RATES/SATURATION AND
   RESULTANT INCREASINGLY MORE WIDESPREAD MODERATE/HEAVY SNOW THROUGH
   THE EARLY MORNING HOURS.
   
   AS OF 09Z...ZERO/SUB-ZERO SURFACE WET BULB TEMPERATURES ARE PRESENT
   ACROSS ALL OF THE TX PANHANDLE/PORTIONS OF THE TX SOUTH
   PLAINS...INTO WESTERN OK AREAS NEAR/NORTH OF I-40. THESE COLDER
   TEMPERATURES ROUGHLY COINCIDE WITH AREAS ALONG AND NORTH-NORTHWEST
   OF A SURFACE INVERTED TROUGH/ZONE OF LOW-LEVEL CONFLUENCE THAT
   ANGLES FROM THE TX SOUTH PLAINS TO EAST-CENTRAL OK. THE ONSET OF
   STRONGER FORCING FOR ASCENT/PRECIPITATION RATES SHOULD QUICKLY ERODE
   TEMPERATURE-DEWPOINT SPREADS THAT ARE AS HIGH AS 10-15F AS OF
   09Z...GENERALLY BY 12Z ACROSS THE MAJORITY OF THE TX PANHANDLE AND
   PERHAPS FAR WESTERN OK. WHILE SOME SLEET WILL BE POSSIBLE INITIALLY
   /ESPECIALLY WITH CONVECTIVE ELEMENTS/...INCREASINGLY MODERATE/HEAVY
   SNOW WILL BE DOMINANT.
   
   CONSEQUENTIAL ASCENT/QUICK SATURATION ASIDE...SNOWFALL RATES WILL
   LIKELY BE ENHANCED BY CONVECTIVE ELEMENTS AS BAND/S OF HEAVIER
   PRECIPITATION EVOLVE. ISOLATED-SCATTERED TSTMS ARE READILY OCCURRING
   AS OF 09Z ACROSS THE TX SOUTH PLAINS INTO NORTHWEST TX. COMBINED
   WITH INCREASING MID-LEVEL FRONTOGENESIS /800-600 MB/...WEAK UPRIGHT
   INSTABILITY AND/OR SLANTWISE INSTABILITY ACROSS THE TX
   PANHANDLE/WESTERN OK WILL LIKELY ENHANCE SNOWFALL RATES TO 1-2 IN/HR
   THROUGH 12Z-15Z ACROSS THE TX PANHANDLE INTO FAR WESTERN OK. THIS
   INCLUDES THE POTENTIAL FOR MULTIPLE/CONSOLIDATING HEAVY SNOW
   BANDS...AS WELL AS THUNDERSNOW.
   
   ..GUYER.. 02/12/2013
   
   
   ATTN...WFO...OUN...LUB...AMA...
   
   LAT...LON   34510222 36160180 36839957 36099893 35299923 34699998
               34030121 34510222