[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 091221
SWOMCD
SPC MCD 091221 
WAZ000-091615-

MESOSCALE DISCUSSION 0032
NWS STORM PREDICTION CENTER NORMAN OK
0621 AM CST MON JAN 09 2006

AREAS AFFECTED...CASCADES OF WESTERN WA

CONCERNING...HEAVY SNOW 

VALID 091221Z - 091615Z

HEAVY SNOWFALL WILL CONTINUE ABOVE THE 3000 TO 3500 FEET LEVEL FOR
MUCH OF THE DAY ACROSS THE CASCADES OF WRN WA. THE SNOW LEVEL SHOULD
SLOWLY RISE WITH SNOWFALL RATES RANGING FROM 1 TO 3 INCHES PER HOUR
WITH THE HEAVIER SNOWBANDS.

WATER VAPOR IMAGERY CURRENTLY SHOWS A EXTENSIVE PLUME OF MOISTURE
EXTENDING NEWD FROM THE FAR ERN PACIFIC ACROSS WA INTO SW CANADA.
THE MOISTURE PLUME IS ASSOCIATED WITH THE RIGHT SIDE OF A 60 KT SWLY
JET AT THE 850 TO 700 MB LEVEL. STRONG ISENTROPIC ASCENT ASSOCIATED
WITH THE SPEED MAX WILL CONTINUE AS THE JET SHIFTS EWD ACROSS THE
MTNS DURING THE DAY. THIS COMBINED WITH TOPOGRAPHIC LIFT AND THE
RELATIVELY HIGH MOISTURE CONTENT IN THE AIR WILL BE SUFFICIENT FOR
HEAVY SNOWFALL RATES IN THE 1 TO 3 INCH PER HOUR RANGE ACROSS THE
CASCADES THROUGH THIS MORNING AND AFTERNOON. AS DAYTIME HEATING
CAUSES TEMPERATURES TO SLOWLY WARM LATE THIS MORNING INTO THE
AFTERNOON...THE SNOW LEVEL SHOULD RISE FROM THE 3000 TO 3500 FOOT
LEVEL TO THE 4000 TO 4500 FOOT LEVEL BY THIS AFTERNOON.

..BROYLES.. 01/09/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OTX...PDT...SEW...PQR...

48792066 48032042 46582083 45862128 45732200 46162260
47692228 48662197 48892152 

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