[MCD] SWOMCD

Fri Jan 5 18:12:47 UTC 2007

ACUS11 KWNS 051816
SWOMCD
SPC MCD 051816 
WAZ000-060015-

MESOSCALE DISCUSSION 0017
NWS STORM PREDICTION CENTER NORMAN OK
1216 PM CST FRI JAN 05 2007

AREAS AFFECTED...OLYMPIC AND NRN CASCADE MTNS OF WA ABOVE 3000 FT

CONCERNING...HEAVY SNOW 

VALID 051816Z - 060015Z

HEAVY SNOW WITH HRLY RATES FROM 1-2 INCHES WILL DEVELOP THROUGH THE
AFTERNOON OVER THE OLYMPIC AND NRN CASCADE MTNS OF WA. SNOW LEVELS
WILL START OUT AROUND 1500 FT...BEFORE RISING TO AROUND 3500 FT BY
00Z. VERY STRONG WINDS /GUSTS FROM 35-45 MPH/ WILL SUPPORT NEAR
BLIZZARD CONDITIONS AT TIMES ABOVE 3500 FT.

AS A WARM FRONT CONTINUES TO MOVE STEADILY EWD THROUGH THE
AFTERNOON...SNOW LEVELS WILL GRADUALLY RISE THROUGH THE AFTERNOON.
STRONG WAA IN ADVANCE OF THIS FRONT WILL SUPPORT CONTINUED
SATURATION OF LOW LEVELS AND DEVELOPMENT OF HVY SNOW INTO THE
OLYMPICS AND NRN CASCADE MTNS OVER THE NEXT SEVERAL HRS. AS A STRONG
UPPER JET ASSOCIATED WITH THE MAIN UPPER TROUGH OFF THE BRITISH
COLUMBIA COAST PROGRESSES TOWARD THE REGION LATER THIS
AFTERNOON...STRONG UPPER DIVERGENCE COUPLED WITH LOW LEVEL WAA WILL
SUPPORT AN INCREASING TREND IN THE SNOWFALL RATES. A WLY WIND SHIFT
IN THE WAKE OF THE WARM FRONT WILL SUPPORTING INCREASING UPSLOPE
FLOW...WITH SNOWFALL RATES POSSIBLY EXCEEDING 2 INCH/HR ABOVE 3500
FT. THE HEAVIEST SNOWFALL IS EXPECTED TO BEGIN OVER THE NRN
CASCADE/OLYMPIC MTNS AFTER 21Z...BEFORE SLOWLY SPREADING SWD  THIS
EVENING. A STRONG PRESSURE GRADIENT /16 MB OVER WA/ WILL SUPPORT
20-30 MPH SUSTAINED WINDS WITH GUSTS OVER 40 MPH. THESE WINDS MAY
SUPPORT NEAR BLIZZARD CONDITIONS AT TIMES IN THE HIGHEST ELEVATIONS.

..CROSBIE.. 01/05/2007

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

47932331 48032387 47822410 47542392 47482380 47462365
47602332 47842314 

48942176 48962214 48382204 47952188 47552183 47112187
46752158 46732132 47332104 48072112 48992129 