[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 071139
SWOMCD
SPC MCD 071139 
WAZ000-071545-

MESOSCALE DISCUSSION 0029
NWS STORM PREDICTION CENTER NORMAN OK
0539 AM CST SUN JAN 07 2007

AREAS AFFECTED...OLYMPIC AND NRN/CENTRAL CASCADE MOUNTAINS ABOVE
3500-4000 FEET

CONCERNING...HEAVY SNOW 

VALID 071139Z - 071545Z

SNOWFALL IS EXPECTED TO INCREASE IN INTENSITY THIS MORNING...WITH
HOURLY RATES UP TO 2 INCH/HOUR LIKELY...AND MAY LOCALLY REACH 3
INCH/HOUR.  SNOW LEVELS WILL CONTINUE TO RISE TO AROUND 4000 FEET
THROUGH 15Z.  STRENGTHENING WLY WINDS SHOULD PRODUCE BLOWING SNOW
AND NEAR BLIZZARD CONDITIONS AT TIMES.

SNOW LEVELS WILL CONTINUE TO RISE DURING THE EARLY MORNING AS A WARM
FRONT MOVES EWD ACROSS THE CASCADES...REACHING CENTRAL WA BY 18Z.
PASSAGE OF THE WARM FRONT WILL ALSO RESULT IN STRENGTHENING DEEP
LAYER WLY WINDS WITH 50-60 KT LIKELY IN THE LOW LEVELS.  THIS
UPSLOPE FLOW INTO THE MOUNTAINS COMBINED WITH LOW LEVEL WAA
SPREADING EWD BENEATH INCREASING ASCENT WITHIN ENTRANCE REGION OF
MID LEVEL JET WILL SUPPORT INCREASING SNOWFALL RATES.  IN
ADDITION...THE STRONGER FLOW WITH SURFACE WINDS AT 25-35 KT...WITH
HIGHER SPEEDS AND GUSTS IN THE VICINITY OF THE CRESTS...WILL LIKELY
PRODUCE AREAS OF BLOWING SNOW AND NEAR BLIZZARD CONDITIONS.

..PETERS.. 01/07/2007

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

...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...OTX...PDT...SEW...

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