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Area Forecast Discussion (AFD)

Issued by Pendleton, OR (PDT)

FXUS66 KPDT 162242

Area Forecast Discussion
National Weather Service Pendleton OR
242 PM PST Sat Feb 16 2019

.SHORT TERM...Tonight through Tuesday...A large and broad trough 
remains over the western states this afternoon. The latest in a 
series of weak lows is descending down the west side of the trough 
and will move ashore over the Willamette Valley tonight and into 
northern California tomorrow. This will keep a chance of light snow 
showers over most of the area tonight though the Washington Columbia 
Basin may not see much. Will keep the Winter Weather Advisory for 
the East Slopes of the Oregon Cascades though do not expect more 
than another inch or so tonight. Most of the rest of the area will 
see a half or less though the eastern Oregon mountains could get up 
to 2 inches. Have kept patchy freezing fog along rivers and streams 
in the Columbia Basin and adjacent valleys overnight and tomorrow 
morning as there has been some fog the last couple of mornings. 
Tomorrow the chance of light snow will be concentrated mainly in the 
eastern Oregon mountains with the Columbia Basin and central Oregon 
drying out. Sunday through Monday night another low will track to 
our east along the Continental Divide in Montana and Wyoming. A cold 
northerly flow will develop. It will be also fairly dry but there 
will be a slight chance of very light upslope snow showers in the 
Washington Cascades and eastern Oregon mountains tapering off to 
nothing by Monday night. A stronger system will approach the area 
out of the Pacific on Tuesday with most of the area seeing a slight 
chance of snow in the afternoon. Temperatures tomorrow will be in 
the upper 20s to mid 30s. With colder air arriving Monday, 
temperatures will be mainly in the 20s with few if any locations 
getting above freezing. Tuesday will be similar though The Dalles 
south to Bend may reach the mid 30s. Perry 

.LONG TERM...Tuesday night through Saturday. Cold temperatures will 
continue through the extended period.  A couple of systems will 
bring another round of snow to the area Tuesday night and Wednesday 
as a low pressure system drops south over Washington and Oregon. 
Behind this system, northerly flow will continue to allow cold air 
to move south over the area with some mainly mountain snow showers. 
Model diverge starting Thursday with the EC being much drier with a 
ridge and weak northwest flow through the weekend, while the GFS has 
more moisture and is showing another cold front by next Sunday. 
Either solution keeps temperatures below normal through the period. 


.AVIATION...00z Tafs.  Area of low pressure will continue to move 
into Oregon tonight with snow showers across the region causing some 
MVFR/IFR with the heavier showers.  Some patchy fog is again 
possible at sites during the early morning hours except for RDM and 
BDN.  Northerly flow and a little drier air starts pushing in from 
north late in the day Sunday. 93 


PDT  24  29  17  25 /  40  30  20  10 
ALW  26  31  18  25 /  40  30  20  10 
PSC  26  31  18  26 /  20  20  10  10 
YKM  23  32  19  27 /  20  10  10  10 
HRI  26  32  19  27 /  20  20  10  10 
ELN  18  32  14  26 /  20  10  20  10 
RDM  19  34  17  32 /  50  10  10  10 
LGD  25  32  18  26 /  50  30  20  10 
GCD  25  34  19  30 /  60  30  10  10 
DLS  26  36  25  33 /  40  10  20  10 


OR...Winter Weather Advisory until 4 AM PST Sunday for ORZ509.