MESOSCALE DISCUSSION 2220
   NWS STORM PREDICTION CENTER NORMAN OK
   1244 AM CST SAT DEC 15 2007
   
   AREAS AFFECTED...NORTHWEST TX
   
   CONCERNING...HEAVY SNOW 
   
   VALID 150644Z - 151045Z
   
   A LOCALIZED BAND OF MODERATE TO OCCASIONALLY HEAVY SNOW...WITH 1
   IN/HR RATES POSSIBLE...IS EXPECTED TO DRIFT SOUTHEASTWARD ACROSS THE
   FAR SOUTHERN TX PANHANDLE/TX SOUTH PLAINS TOWARD THE CAPROCK
   VICINITY OVER THE NEXT FEW HOURS. THIS INCLUDES THE PLAINVIEW AND
   LUBBOCK AREAS.
   
   COINCIDENT WITH DEEPENING MID LEVEL TROUGH ACROSS THE HIGH
   PLAINS...INFRARED SATELLITE IMAGERY IN TANDEM WITH VOLUMETRIC RADAR
   DATA REFLECTS AN ENHANCED SOUTHWEST-NORTHEAST ORIENTED BAND OF SNOW
   ACROSS THE TX PANHANDLE/SOUTH PLAINS OF NORTHWEST TX. OWING TO LOW
   LEVEL COLD ADVECTION AND INCREASING PRECIPITATION RATES...THE
   SURFACE WET BULB ZERO LINE HAS MADE A FAIRLY AGGRESSIVE SOUTHWARD
   PUSH ACROSS THE TX PANHANDLE/TX SOUTH PLAINS OVER THE PAST FEW
   HOURS...WITH THE 32F WET BULB LINE AT 06Z AS FAR SOUTHEAST AS THE
   LUBBOCK/CHILDRESS AREAS. WITH SLEET ALREADY REPORTED AT LUBBOCK AS
   OF 06Z...A QUICK CHANGE-OVER TO MODERATE/PERHAPS LOCALLY HEAVY SNOW
   APPEARS IMMINENT FOR THE PLAINVIEW/LUBBOCK VICINITIES PER
   OBSERVATIONAL TRENDS. WITH A RESPECTABLE HANDLE OF THIS EXISTING
   PRECIPITATION BAND...00Z NAM SOUNDINGS SUPPORT THE POSSIBILITY OF
   LOCALIZED 1 IN/HR SNOW RATES /THROUGH AROUND 09Z OR 10Z/ VIA AMPLE
   OMEGA COINCIDENT WITH A SATURATED DENDRITIC LAYER.
   
   ..GUYER.. 12/15/2007
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
   SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
   TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
   FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.
   
   ATTN...WFO...LUB...AMA...
   
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