[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 151859
SWOMCD
SPC MCD 151858 
ORZ000-WAZ000-152330-

MESOSCALE DISCUSSION 0104
NWS STORM PREDICTION CENTER NORMAN OK
1258 PM CST SAT JAN 15 2005

AREAS AFFECTED...NW/CNTRL ORE AND PORTIONS SW/CNTRL WA

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 151858Z - 152330Z

COMBINATION OF FZRA/SLEET EXPECTED TO DEVELOP EWD ACROSS THE
COLUMBIA GORGE/CASCADES THROUGH 00Z...WHILE FZRA CHANGES TO RAIN IN
THE WILLAMETTE VALLEY/WA INTERIOR VALLEY AROUND/AFTER 21Z.

WV IMAGERY PORTRAYS VORT MAX OFF THE PACIFIC NW COAST AROUND
43N/130W. LATEST SURFACE ANALYSIS FEATURES 1044 MB HIGH PRESSURE
EXTENDING ACROSS ERN WA...WITH MODIFIED ARCTIC AIRMASS THROUGH THE
COLUMBIA BASIN/COLUMBIA GORGE INTO NCNTRL/NE ORE. AT 18Z...MESONET
OBS FEATURE FZRA REPORTS IN WILLAMETTE VALLEY/WA INTERIOR VALLEY
FROM OLM-PDX-SLE WITH SFC TEMPS HOLDING AROUND 29F-31F. IN THIS
CORRIDOR...15Z RUC PRECIP TYPE ALGORITHMS/SOUNDINGS SUGGEST CHANGE
OVER TO ALL RAIN AROUND/AFTER 21Z OWING TO MID LEVEL WARM AIR
ADVECTION/WARMING SFC TEMPS. FURTHER EAST...IN THE COLUMBIA
GORGE/CASCADES/ERN SLOPES...AS PRECIP SHIELD EXPANDS EWD THIS
AFTERNOON...LIGHT SNOW EXPECTED TO YIELD TO SLEET AND/OR FZRA AS
SHALLOW COLD AIRMASS REMAINS ENTRENCHED BELOW ENCROACHING WARM LAYER
BASED AROUND 850-900 MB.

..GUYER.. 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...BOI...PDT...SEW...PQR...

46912270 47002159 46272031 45901994 45471955 45051916
44231920 43881937 43852117 44552287 45002301 

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