Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 211557

Area Forecast Discussion
National Weather Service Pendleton OR
757 AM PST Wed Feb 21 2018

.UPDATE...A shortwave is exiting to the south and weakening. Snow
has diminished area wide, with residual isolated snow showers
across Central Oregon ending by mid/late morning. Thus, have
cancelled the winter weather advisories. Part;y to mostly cloudy
skies will prevail for the remainder of today, with cold high
temperatures in the lower/mid 30s for the lower elevations and
mainly 20s for the mountains. The next shortwave will enter the
area from the north tonight. This feature looks weaker than last
night`s shortwave, thus will cap PoPs in the low/mid end chance
category for mainly the higher elevations and Central Oregon.
Expect any snow accumulations to be light, with perhaps an inch or
two for the mountains.


.AVIATION...12Z TAFS...Mostly VFR conditions are expected through
the period. MVFR/IFR conditions this morning at KBDN and RDM due to
low ceilings in -SN and BR will improve by 18Z. The rest of the day
will see scattered clouds at 4-6 thousand feet and mid and high
clouds above. By late afternoon/early evening expect bkn-ovc
conditions at 4-5 thousand feet AGL. Light snow will develop tonight
at KDLS...KRDM...and KBDN with MVFR/LCL IFR CIGS/VSBYS. Winds will
be mostly light and VRBL. 78


.PREV DISCUSSION... /issued 304 AM PST Wed Feb 21 2018/

SHORT TERM...Today through Friday...A shortwave is moving south
through the area early this morning and snow is decreasing into
light showers from north to south. At this point light snow showers
continue from the Columbia Gorge and the Blue Mountains southward
but should end later this morning. Will keep current Winter Weather
Advisories for now but will likely end at least the northern zones
in the next couple of hours. Liquid equivalent precipitation amounts
are barely measurable but the area from Madras and John Day
southward could get another half inch to an inch of snow. Skies are
clearing in the north and expect this morning will be sunny in the
north and becoming partly cloudy in the south. This afternoon
another wave will move south out of British Columbia and into the
area this evening. The wave will form a weak low over the Columbia
basin on Thursday and drift off to the east Thursday night. This
will bring another chance of snow to the mountains and Central
Oregon though the Columbia Basin will be mainly dry on Wednesday
night and Thursday. Snow amounts look lighter than the current wave
and snow amounts for the 24 hours will be generally less than an
inch with 1-2 inches possible south and west of Bend. Snow showers
will taper off Thursday evening. Overnight and Friday morning will
be a break between systems and there will be a cool northerly flow
over the area. Another wave will approach the area Friday afternoon
with a chance of snow along the Cascades and a slight chance of snow
as far east as Ellensburg, Yakima and The Dalles. Temperatures today
will be in the lower to mid 30s with mid 20s to lower 30s in the
mountains. Temperatures will then warm a couple of degrees each day
and end up in the upper 30s to lower 40s with upper 20s to mid 30s
in the mountains Friday. Perry

LONG TERM...Friday night through Tuesday...The next is a series of
shortwave troughs dropping sewd in the nwly flow aloft will move
across the area Friday night with a chance of snow mainly over the
mountains...with shadowing over the Columbia Basin. The snow will
continue in earnest over the eastern mountains on Saturday with some
potential need for winter highlights over the Blue Mountains. The
precipitation will taper off to scattered mainly mountain snow
showers Saturday night and Sunday before yet another system moves in
for Sunday night and Monday. This storm looks like it could produce
sufficient QPF for winter highlights as well especially in Oregon.
By Tuesday a more northerly flow develops over the region which
should result in less precipitation...but there will still be
scattered mountain snow showers. Snow levels will be low through the
period running 1-2 thousand feet during the day and 500-1000 feet at
night. 78


PDT  33  19  34  16 /  10  10  10  10
ALW  35  22  38  20 /   0  10  10  10
PSC  36  22  39  20 /   0  10  10  10
YKM  34  20  38  19 /   0  10  10  10
HRI  35  21  37  18 /   0  10  10  10
ELN  32  18  36  17 /   0  20  10  10
RDM  30  15  28   8 /  30  30  30  20
LGD  30  19  29  13 /  20  30  30  20
GCD  31  19  30  13 /  30  30  30  20
DLS  35  22  38  21 /  10  20  20  10




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