MESOSCALE DISCUSSION 0155
   NWS STORM PREDICTION CENTER NORMAN OK
   0702 PM CST SUN FEB 27 2011
   
   AREAS AFFECTED...CASCADES OF WA
   
   CONCERNING...HEAVY SNOW 
   
   VALID 280102Z - 280700Z
   
   SNOWFALL RATES OF 2 INCHES PER HOUR...WITH LOCALLY HIGHER
   RATES...ARE ANTICIPATED ACROSS THE CASCADES OF WA THIS EVENING INTO
   TONIGHT.
   
   STRONG LOW/MID-LEVEL W-SWLY TO WLY FLOW /CURRENTLY 80-85 KT AT 500
   MB PER RUC ANALYSIS/ WILL CONTINUE TO IMPACT THE PACIFIC NW INTO
   TONIGHT AHEAD OF LOW PRESSURE DROPPING S-SEWD NEAR THE PACIFIC
   COAST. AS DEEP-LAYER MOISTURE /PWAT VALUES AROUND 0.50 INCH
   ACCORDING TO AMSU-SSMI BLENDED TPW IMAGERY/ IMPINGES ON THE
   CASCADES...THE UPSLOPE COMPONENT OF THE FLOW WILL SUPPORT SNOWFALL
   WITH RATES OF 2 INCHES PER HOUR THIS EVENING INTO TONIGHT. THIS WILL
   BE FURTHER ENHANCED BY INCREASING DEEP-LAYER ASCENT OVERNIGHT
   TONIGHT. THIS WILL ESPECIALLY BE THE CASE OVER THE CASCADES OF SRN
   WA...WHERE THE 21Z RUN OF THE EXPERIMENTAL HRRR DEPICTS THE HIGHEST
   SNOWFALL RATES /POTENTIALLY UP TO 3 INCHES PER HOUR/ AFTER 06Z.
   
   ..COHEN.. 02/28/2011
   
   
   ATTN...WFO...OTX...PDT...SEW...PQR...
   
   LAT...LON   45712201 45772253 46182279 46562269 46862225 47012209
               47372191 47902189 48122195 48512208 48822198 48942167
               48962105 48672069 48102048 47342091 46342109 45992141
               45812171 45712201