[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 151212
SWOMCD
SPC MCD 151211 
ORZ000-WAZ000-151615-

MESOSCALE DISCUSSION 0103
NWS STORM PREDICTION CENTER NORMAN OK
0611 AM CST SAT JAN 15 2005

AREAS AFFECTED...NWRN AND N-CENTRAL ORE...AND FAR SRN WA

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 151211Z - 151615Z

COVERAGE OF MIXED PRECIPITATION IS EXPECTED TO INCREASE ACROSS
NWRN/N-CENTRAL ORE THROUGH 18Z WITH PRECIPITATION GRADUALLY LIFTING
NWD INTO THE COLUMBIA RIVER BASIN. AREAS OF FREEZING RAIN ARE LIKELY
IN THE WILLAMETTE VALLEY FROM EUG TO PDX...WITH SNOW DEVELOPING
ALONG THE CASCADES OF NRN ORE EWD ALONG THE COLUMBIA RIVER BASIN
THROUGH 15/18Z.

ARCTIC AIR MASS HAS WORKED WEST OF THE CONTINENTAL DIVIDE AS
EVIDENCED BY 1041MB SURFACE RIDGE ACROSS THE COLUMBIA BASIN.
SUBFREEZING SURFACE TEMPERATURES WITH RELATIVELY LARGE DEWPOINT
DEPRESSIONS EXIST ALONG THE COLUMBIA RIVER BASIN WWD TO PDX.
MEANWHILE...A WARM FRONT IS LOCATED FROM 25 N OTH SEWD ACROSS
INTERIOR SWRN ORE. ISENTROPIC LIFT WILL INCREASE ACROSS NWRN ORE
DURING THE NEXT SEVERAL HOURS AS FRONT LIFTS SLOWLY NWD. SHORTWAVE
500MB RIDGE IN PLACE ALONG THE WA/ORE COAST IS SLOWING PROGRESS OF
PRECIPITATION DEVELOPMENT...HOWEVER...LIGHT FREEZING RAIN HAS BEEN
NOTED AT EUG SINCE 1044Z AND SHOULD DEVELOP NWD THROUGH THE
REMAINDER OF THE WILLAMETTE VALLEY DURING THE NEXT 1-2 HOURS. COLD
AIR MASS IS DEEPER AND WILL REMAIN FIRMLY ENTRENCHED ALONG THE
COLUMBIA GORGE INTO THE AFTERNOON HOURS. PRECIPITATION SHOULD BE IN
THE FORM OF SNOW THROUGH 18Z...WITH PERHAPS SOME SLEET MIXING IN
TOWARD EARLY AFTERNOON. WET BULB COOLING AND DRAINAGE FLOW WITHIN
THE RIVER BASIN SHOULD SLOW EFFECTS OF LARGE-SCALE WARM
ADVECTION...ESPECIALLY EAST OF THE CASCADES.

..BANACOS.. 01/15/2005

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 00-01 UTC...
06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28.

ATTN...WFO...PDT...MFR...PQR...

43692281 44002325 44412351 44972353 45772343 45952322
45982280 45882236 45842182 45832142 45752120 45532101
45152089 44732093 44272096 44042108 43722150 43472187 

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