MESOSCALE DISCUSSION 0329
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 PM CDT SUN MAR 24 2013
   
   AREAS AFFECTED...SE OHIO...NRN WV...SW PA...FAR NW VA...WRN MD
   PANHANDLE
   
   CONCERNING...HEAVY SNOW 
   
   VALID 250435Z - 250930Z
   
   SUMMARY...MODERATE TO HEAVY SNOW IS EXPECTED OVERNIGHT ACROSS
   PORTIONS OF THE UPPER OHIO VALLEY INTO NW VA/WRN MD PANHANDLE. RATES
   UP TO AN INCH PER HOUR WILL BE POSSIBLE AT TIMES INTO THE EARLY
   MORNING HOURS.
   
   DISCUSSION...A BAND OF HEAVY SNOW CURRENTLY SITUATED FROM WRN OHIO
   INTO PORTIONS OF NRN AND CNTRL WV WILL CONTINUE TO PIVOT E/NE
   OVERNIGHT AS MIDLEVEL TROUGH CONTINUES TO TRACK ACROSS THE OHIO
   VALLEY. DEEP LAYER ASCENT AHEAD OF THE TROUGH COINCIDING WITH
   FAVORABLE DEFORMATION ZONE/MODEST FRONTOGENESIS WILL HELP TO
   MAINTAIN MODERATE TO HEAVY SNOW AT TIMES ACROSS PARTS OF THE UPPER
   OHIO VALLEY/CENTRAL APPALACHIANS/SHENANDOAH VALLEY REGION. PW VALUES
   HAVE DECREASED SOMEWHAT FROM EARLIER IN THE DAY TO AROUND A HALF
   INCH. ADDITIONALLY...LITTLE IF ANY IN THE WAY OF ELEVATED
   INSTABILITY EXISTS ACROSS THE REGION. THIS SHOULD THEREFORE TEMPER
   SNOWFALL RATES COMPARED TO THOSE SEEN FURTHER WEST EARLIER TODAY AND
   THIS EVENING ACROSS THE MIDWEST...BUT GIVEN THE DYNAMIC SYSTEM AND
   MORE THAN ADEQUATE DEEP LAYER MOISTURE THROUGH DENDRITIC GROWTH
   ZONE...SNOWFALL RATES APPROACHING ONE INCH PER HOUR AT TIMES SEEMS
   POSSIBLE THROUGH THE EARLY MORNING HOURS. 
   
   MOST TEMPERATURES ACROSS THE REGION ARE AT OR BELOW FREEZING.
   HOWEVER...A FEW LOCATIONS STILL REMAIN AROUND 33-35 DEGREES. WITH
   THE ONSET OF PRECIPITATION...WET BULB AND EVAPORATIVE PROCESSES IN
   LOW LEVELS SHOULD QUICKLY CHANGE ANY RAIN OR MIXED PHASE
   PRECIPITATION TO ALL SNOW.
   
   ..LEITMAN.. 03/25/2013
   
   
   ATTN...WFO...CTP...LWX...PBZ...RLX...
   
   LAT...LON   39978185 40238175 40528128 40768017 40807967 40727901
               40357835 39887793 39577787 39027791 38667825 38277889
               38197937 38738023 39568146 39978185