290 
FXUS66 KPDT 041000
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
259 AM PDT Sat Nov 4 2017

.SHORT TERM...Today through Sunday Night...An upper level trough 
remains over the Pacific Northwest this morning. A disturbance that 
moved through the area yesterday has moved to the east and the flow 
aloft has shifted to the northwest. A few snow showers linger over 
the Blue Mountains but otherwise the area is in a lull before the 
next system moves through the area starting late this afternoon. 
Today should be dry in the lower elevations with increasing clouds 
through the day. A chance of mainly light snow showers will continue 
this morning in the Cascades and eastern mountains. By the 
afternoon, a warm front will begin to cross the Cascades and will 
bring additional snow showers to the Washington Cascades, the Yakima 
and Kittitas valleys and the Simcoe Highlands tonight. Already have 
a Winter Weather Advisory for snow for the East Slopes of the 
Washington Cascades and the Yakima and Kittitas Valleys for tonight 
and Sunday and have added the Simcoe Highlands. Snow levels in the 
advisory area will be starting out at 1500-2000 feet in the evening 
but will lower to the surface overnight and Sunday. The rest of the 
area will see precipitation increasing after midnight as the cold 
front crosses the Cascades overnight. Through Sunday afternoon, 
anticipate the Yakima and Kittitas Valleys getting 2-4 inches of 
snow, the Simcoe Highlands 4-6 inches and the East Slopes of the 
Washington Cascades 4-8 inches, which will impact travel through 
highway passes. See product PDXWSWPDT for additional information. 
Away from the advisory area, snow levels will begin at 2500-3500 
feet and drop to around 1500-2000 feet. Precipitation will be 
lighter from the Columbia Basin eastward but the lower elevations 
could get a dusting of snow Saturday night and Sunday morning. 
Central Oregon, especially south and west of Bend could get 2-3 
inches of snow. Sunday night there will continue to be a chance of 
mainly snow showers with snow levels near or at the surface over 
nearly the entire area. However, precipitation amounts will be 
greatly decreasing Sunday evening west of the eastern mountains. 
Some additional winter weather highlights may be need for Sunday 
through Monday morning for Wallowa county and perhaps the Blue 
Mountain Foothills but have held off for now as snow amounts are 
coming up a little short of the criteria and snow levels are a bit 
uncertain. High temperatures will be in the mid 30s to mid 40s today 
and a couple of degrees cooler on Sunday. Lows will be in the lower 
to mid 30s with 20s in the mountains tonight and in the mid 20s to 
around 30 with upper teens to mid 20s in the mountains Sunday night. 
Perry

.LONG TERM...Monday through Saturday...The departing upper level 
trough will leave some lingering showers over the area Monday but 
then come to an end by evening. Ridge of high pressure will then set 
up over the region Tuesday and Wednesday for dry conditions. A new 
upper level trough will form in the eastern Pacific midweek and then 
move inland Thursday and Friday for a return to wet and unsettled 
conditions. Snow levels will be 2000 to 4000 feet. The trough exits 
late Friday leaving a flat westerly flow with some lingering showers 
mainly near the Cascades and over the eastern mountains on Saturday. 

&&

.AVIATION...Previous discussion...06z TAFS. Sct-bkn 040-070 
overnight with isolated showers. Winds less than 10kt. Sct-bkn 040-
080 bkn-ovc 100-150 Saturday with a low pressure system approaching. 
Ceilings lowering to bkn-ovc 030-050 late afternoon and evening with 
rain developing. Winds 5-15kt. 

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  44  33  41  30 /  20  40  80  60 
ALW  45  34  42  30 /  20  40  80  60 
PSC  46  34  40  30 /  10  50  80  50 
YKM  41  30  36  24 /  10  90  80  40 
HRI  46  33  42  29 /  10  50  80  50 
ELN  40  27  36  19 /  20  90  90  40 
RDM  41  28  40  24 /  10  40  70  40 
LGD  41  29  39  27 /  20  30  80  70 
GCD  38  29  38  26 /  10  20  80  60 
DLS  48  35  44  31 /  20  80  80  50 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...Winter Weather Advisory from 5 PM PDT this afternoon to 4 PM PST 
     Sunday for WAZ026-027-520-521.

&&

$$

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