[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 191557
SWOMCD
SPC MCD 191557 
IDZ000-ORZ000-WAZ000-192000-

MESOSCALE DISCUSSION 2582
NWS STORM PREDICTION CENTER NORMAN OK
0957 AM CST MON DEC 19 2005

AREAS AFFECTED...ERN/NRN ORE...SERN WA...AND WRN ID

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 191557Z - 192000Z

FREEZING RAIN WILL DIMINISH IN INTENSITY OVER THE WRN COLUMBIA RIVER
GORGE THROUGH 18Z...WHILE A MIX OF SLEET AND FREEZING RAIN WILL
DEVELOP FURTHER EAST OVER THE COLUMBIA RIVER BASIN OF NERN ORE/SERN
WA THROUGH 20Z. HRLY ACCUMULATIONS UP TO 0.10 FOR AN HOUR OR TWO
WILL BE POSSIBLE. FURTHER SOUTH...LIGHT SNOW WILL CONTINUE TO
DEVELOP OVER THE TREASURE VALLEY OF FAR SERN ORE/SWRN ID THROUGH
18Z...BEFORE A MIX AND THEN CHANGE OVER TO SLEET/FREEZING RAIN
OCCURS IN THIS AREA BETWEEN 18-20Z. ACCUMULATIONS RATES UP TO 0.10
INCH/HR WILL BE POSSIBLE IN THIS AREA AS WELL.

STRONG MID LEVEL ISENTROPIC LIFT WAS CONTRIBUTING TO AN ORGANIZED
NW-SE ORIENTED BAND OF PRECIPITATION MOVING EWD ACROSS SRN WA AND
ERN ORE. AS THE UPPER WAVE CONTRIBUTING TO THIS LIFTS INTO BRITISH
COLUMBIA...EXPECT A STEADY EWD PROGRESS OF THIS PRECIPITATION ACROSS
MUCH OF NERN ORE/SERN WA THROUGH THE EARLY AFTERNOON HOURS. RECENT
RUC/NAM FORECAST SOUNDINGS INDICATE THAT LIGHT SNOW WILL CHANGE OVER
TO FREEZING RAIN OVER MUCH OF THE COLUMBIA RIVER BASIN OF NERN
ORE/SERN WA THROUGH 20Z. FURTHER EAST...ISENTROPIC ASCENT WAS JUST
NOW MOVING INTO THE UPPER TREASURE VALLEY OF SERN ORE/SWRN ID. IN
THIS AREA...STRONG WAA...EVIDENT BY 60 KT SWLY JET AT 700 MB PER
MEDFORD VWP...SUGGESTS THAT LIGHT SNOW NOW DEVELOPING INTO THIS AREA
WILL CHANGE OVER TO FREEZING RAIN/SLEET BETWEEN 18-20Z.

..CROSBIE.. 12/19/2005

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

ATTN...WFO...MSO...BOI...OTX...PDT...SEW...PQR...

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