MESOSCALE DISCUSSION 0049
   NWS STORM PREDICTION CENTER NORMAN OK
   1019 AM CST WED JAN 26 2011
   
   AREAS AFFECTED...CNTRL/ERN WV...WRN MD...NWRN VA
   
   CONCERNING...HEAVY SNOW 
   
   VALID 261619Z - 262015Z
   
   SNOWFALL WITH RATES OF 1-2 IN/HR IS EXPECTED TO DEVELOP ACROSS
   CNTRL/ERN WV...AND PERHAPS WRN MD...DURING THE NEXT FEW HRS...AND
   THEN SPREAD EWD ACROSS NWRN VA BY EARLY TO MID AFTERNOON.
   
   LATE MORNING WV IMAGERY SHOWS AN UPPER TROUGH BECOMING INCREASINGLY
   NEGATIVELY TILTED AS IT PROGRESSES NEWD TOWARD THE MID ATLANTIC
   REGION. INTENSE DEEP LAYER ASCENT ACCOMPANYING THE UPPER DISTURBANCE
   IS CURRENTLY SPREADING INTO WV...AIDING IN DYNAMIC COOLING OF THE
   ATMOSPHERIC COLUMN AND REMOVAL OF A WARM LAYER OF AIR OBSERVED BELOW
   800 MB PER 12Z OBSERVED RNK RAOB. AS THIS OCCURS...PRECIPITATION IS
   EXPECTED TO QUICKLY TRANSITION TO SNOW OVER CNTRL/ERN WV. GIVEN THE
   VERY STRONG DEEP LAYER ASCENT OCCURRING THROUGH THE DENDRITIC GROWTH
   ZONE...SNOWFALL RATES OF 1-2 IN/HR APPEAR PROBABLE.
   
   BY EARLY TO MID AFTERNOON...STRONG ASCENT ACCOMPANYING THE UPPER
   TROUGH IS FORECAST TO EXIT WV AND MOVE ACROSS NWRN VA. PRECIPITATION
   OVER THIS AREA MAY BRIEFLY TRANSITION TO FREEZING RAIN OR
   SLEET...BEFORE PREDOMINANT PRECIPITATION TYPE BECOMES SNOW BY 20Z.
   STRONG ASCENT COUPLED WITH MUCAPE VALUES OF 50-150 J/KG ROOTED IN
   THE 700-600 MB LAYER SUGGEST THAT SNOWFALL RATES OF 1-2 IN/HR WILL
   BE POSSIBLE ACROSS NWRN VA AS WELL.
   
   ..GARNER.. 01/26/2011
   
   
   ATTN...WFO...AKQ...LWX...RNK...PBZ...RLX...
   
   LAT...LON   38597785 37767842 37278091 37608173 38608172 39597988
               39557820 38597785