MESOSCALE DISCUSSION 0013
   NWS STORM PREDICTION CENTER NORMAN OK
   1204 AM CST MON JAN 05 2009
   
   AREAS AFFECTED...PARTS OF WA...NERN ORE AND W-CENTRAL/NRN ID
   
   CONCERNING...HEAVY SNOW 
   
   VALID 050604Z - 051000Z
   
   HEAVY SNOWFALL RATES OF 1 TO 2 INCHES/HR ARE LIKELY AT TIMES THROUGH
   12Z OVER PARTS OF WA...NERN ORE AND AFTER 09Z OVER W-CENTRAL/NRN ID.
   
   
   06Z REGIONAL RADAR MOSAIC INDICATES PRECIPITATION HAS BEGUN TO
   OVERSPREAD MUCH OF ERN WA.  SURFACE OBSERVATIONS WITHIN THE PAST
   HOUR AT SEA AND EPH ARE REPORTING HEAVY AND MODERATE SNOW
   RESPECTIVELY.  THIS HEAVY SNOW REGIME WILL LIKELY CONTINUE EWD AS
   STRONG LOW LEVEL WARM ADVECTION IMPLIED BY 00Z/05 UIL RAOB AND AREA
   VWP/S WILL CONTINUE TO PUSH INTO INTERIOR WA/ORE.  DESPITE INITIAL
   RELATIVELY DRY LOW LEVELS OVER ERN LOCALES...FORECAST SOUNDINGS
   INDICATE TOP-DOWN MOISTENING WILL OCCUR RAPIDLY WITH TIME...LEADING
   TO A DEEP /AOA 400MB/ SATURATED COLUMN.  THIS WILL BE FAVORABLY
   TIMED WITH STRONG UVV/S OVERSPREADING THE REGION FROM THE W. 
   ADDITIONAL LIFT DUE TO OROGRAPHIC CONTRIBUTIONS ON SW FACING SLOPES
   SHOULD ACT TO ENHANCE PRECIPITATION RATES FURTHER.  LATEST
   DETERMINISTIC/ENSEMBLE QPF SUGGEST OCCASIONAL SNOW RATES OF 1 TO 2
   INCHES/HR WILL BE COMMON.  SNOWFALL RATES OVER MUCH OF WA ARE
   EXPECTED TO WANE FROM W TO E TOWARDS THE END OF THE PERIOD AND AREAS
   WILL PROBABLY BEGIN TO CHANGE RAIN IN WRN AREAS AS TEMPS WARM
   TOWARDS 12Z.
   
   ..SMITH.. 01/05/2009
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
   SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
   TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
   FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.
   
   ATTN...WFO...PIH...MSO...BOI...OTX...PDT...SEW...PQR...
   
   LAT...LON   46691461 45231395 43541494 43391648 45071788 47551916
               47372044 46112131 46042222 48982261 48912041 48661666
               46691461