MESOSCALE DISCUSSION 0177
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CST WED FEB 20 2013
   
   AREAS AFFECTED...NE OK...FAR NW AR
   
   CONCERNING...HEAVY SNOW 
   
   VALID 201730Z - 201930Z
   
   SUMMARY...HEAVY SNOW...WITH RATES NEAR 1 INCH/HOUR...IS POSSIBLE
   OVER THE AREA FOR THE NEXT HOUR OR TWO. AN END TO THE PRECIPITATION
   IS EXPECTED SOON AS DRIER AIR MOVED INTO THE REGION.
   
   DISCUSSION...SURFACE OBSERVATIONS AND RADAR IMAGERY INDICATES A BAND
   OF HEAVY SNOW ORIENTED NW TO SE ACROSS NE OK AND FAR NW AR. SURFACE
   TEMPERATURES ARE AT OR JUST BELOW FREEZING WITH RAP SOUNDINGS
   INDICATING A SATURATED PROFILE THROUGH MUCH OF THE COLUMN.
   HOWEVER...RECENT RADAR IMAGERY SHOWS A DRYING TREND AROUND
   PAWNEE...CREEK...AND OKFUSKEE COUNTIES IN NE OK. THIS DRYING IS
   LIKELY ASSOCIATED WITH SUBSIDENCE BEHIND THE SUBTLE SHORTWAVE WHICH
   INITIATED THE WINTER PRECIPITATION. AS SUCH...THE HEAVY SNOW NEAR
   TUL AND GCM WILL LIKELY END WITHIN THE HOUR. FARTHER S AND E...THE
   HEAVY SNOW WILL CONTINUE FOR LONGER...BUT THE SUBSIDENCE WILL LIKELY
   AFFECT THIS AREA WITHIN THE NEXT 2 HOURS...LEADING TO AN END OF THE
   SNOWFALL THERE AS WELL.
   
   PRECIPITATION IS LIKELY TO BEGIN AGAIN LATER THIS AFTERNOON...BUT
   PROFILES FROM I-40 SWD APPEAR THEY WILL BE TOO WARM FOR SNOW.
   
   ..MOSIER.. 02/20/2013
   
   
   ATTN...WFO...LZK...SGF...TSA...ICT...
   
   LAT...LON   36439622 36709643 36999585 36619449 35019332 34469387
               35819571 36439622