[MCD] SWOMCD

Sat Jan 6 00:41:47 UTC 2007

ACUS11 KWNS 060045
SWOMCD
SPC MCD 060045 
WAZ000-ORZ000-060645-

MESOSCALE DISCUSSION 0023
NWS STORM PREDICTION CENTER NORMAN OK
0645 PM CST FRI JAN 05 2007

AREAS AFFECTED...CASCADES OF WA/NRN ORE ABOVE 3500 FT

CONCERNING...HEAVY SNOW 

VALID 060045Z - 060645Z

HEAVY SNOW WITH RATES UP TO 2 INCH/HR WILL CONTINUE TO DEVELOP SWD
THROUGH WA CASCADES INTO THE NRN ORE CASCADES THROUGH 06Z. SNOW
LEVELS WILL CONTINUE TO SLOWLY RISE TO AROUND 3500 FT THROUGH THE
EVENING. STRONG WINDS WILL LEAD TO NEAR BLIZZARD CONDITIONS AT TIMES
IN THE HIGHEST ELEVATIONS.

A VERY DYNAMIC SHORTWAVE TROUGH WILL CONTINUE TO APPROACH THE COAST
OF SRN BRITISH COLUMBIA AND WA OVER THE NEXT 6 HOURS. AHEAD OF THIS
SHORTWAVE...STRONG WARM ADVECTION /PER THE 00Z SLE SOUNDING/ COUPLED
WITH STRONG SWLY /UPSLOPE/ LOW LEVEL FLOW AND UPPER LEVEL DIVERGENCE
WILL SUPPORT A VERY STRONG VERTICAL MOTION PROFILE OVER WA AND NRN
ORE CASCADES DURING THE NEXT 6+ HRS. BASED ON PRESENT SYSTEM
MOTION...THE STRONGEST VERTICAL MOTION FIELDS WILL OCCUR OVER THE
NRN WA CASCADES THROUGH 06Z...WHILE GRADUALLY DEVELOPING SWD INTO
THE SRN WA/NRN ORE CASCADES BETWEEN 03-06Z AS THE UPPER DIVERGENCE
MAXIMUM AND MID LEVEL COLD FRONT MOVE SEWD. GIVEN THE STRENGTH OF
THE MESOSCALE FORCING...SNOWFALL RATES UP TO 2 INCH/HR WILL BE
COMMONPLACE FOR MORE THAN A 6 HR PERIOD ESPECIALLY ACROSS THE WRN
SLOPES. SNOWFALL LEVELS /PRESENTLY AROUND 2500 FT/ WILL CONTINUE TO
RISE TO AROUND 3500 FT /PER THE UIL 00Z SOUNDING/ OVER THE NEXT FEW
HRS UNDER THE PRESENCE OF CONTINUED STRONG WAA. A STRONG SFC
PRESSURE/HEIGHT GRADIENT WILL SUPPORT SUSTAINED SSWLY WINDS FROM
20-30 MPH WITH GUSTS OVER 40 MPH...LEADING TO NEAR BLIZZARD
CONDITIONS AT TIMES IN THE HIGHEST TERRAIN.

..CROSBIE.. 01/06/2007

...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...PQR...

48812098 48792167 48542189 47992186 46982174 46232200
45692206 45242216 44702242 44472205 44512171 45352150
46662104 47682095 48522088 