MESOSCALE DISCUSSION 0223
   NWS STORM PREDICTION CENTER NORMAN OK
   0949 PM CDT MON MAR 09 2009
   
   AREAS AFFECTED...MUCH OF WY...WRN SD
   
   CONCERNING...HEAVY SNOW 
   
   VALID 100249Z - 100645Z
   
   MODERATE TO HEAVY SNOW...ALREADY NOTED OVER MUCH OF WY...WILL
   CONTINUE TO SPREAD ENEWD INTO WRN SD. RATES NEAR 1 TO 2 INCHES AN
   HOUR WILL BE LIKELY...WITH 3 INCH AN HOUR POSSIBLE OVER HIGHER
   ELEVATIONS. SURFACE WINDS NEAR 15 TO 20 MPH WILL FURTHER REDUCE
   VISIBILITIES IN HEAVY SNOW.
   
   SATELLITE IMAGERY REFLECTS A BAROCLINIC LEAF FROM SERN UT NEWD INTO
   SWRN ND WHERE STRONG 850 TO 700 MB FRONTOGENESIS IS ONGOING AHEAD OF
   A COLD UPPER TROUGH. MUCH OF WYOMING REMAINS UNDER FAVORABLE
   ANTICYCLONIC JET DYNAMICS AS A 65 KT JET MAXIMA...NOTED ON PROFILER
   DATA...ACCELERATES NEWD. 00Z SOUNDINGS AND MODEL FORECASTS OVER THE
   NEXT FEW HOURS INDICATE AN ATMOSPHERIC PROFILE FAVORABLE TO HEAVY
   SNOWFALL...WITH NEARLY SATURATED COLUMNS AND A DEEP ISOTHERMAL LAYER
   FROM JUST ABOVE THE SURFACE THROUGH ABOUT 650 MB. PROFILES WILL
   REMAIN SATURATED AS PRECIPITATION CONTINUES...AND GREATER MOISTURE
   TO THE S IS DRAWN NWD IN SLY/SWLY 700 MB FLOW. ISENTROPIC LIFT WILL
   CONTINUE TO BE MAXIMIZED OVER CNTRL WY NEWD INTO NWRN SD...GRADUALLY
   SPREADING ENEWD OVERNIGHT. IN WY...SWLY FLOW WILL CONTRIBUTE TO
   HIGHER SNOWFALL RATES IN FAVORABLY ORIENTED SLOPES...WHILE IN SD THE
   BLACK HILLS WILL SUPPORT HIGHER RATES AS WELL.
   
   ..HURLBUT.. 03/10/2009
   
   
   ATTN...WFO...ABR...UNR...CYS...BYZ...RIW...
   
   LAT...LON   41900530 41360793 41420954 42300985 43100935 43740768
               45190464 45780308 45670147 44660132 42650396 41900530