988
FXUS66 KPDT 180527
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1027 PM PDT Fri Oct 17 2025

.Updated Aviation Discussion.


.AVIATION...06Z TAFS...VFR conditions currently across all sites,
which will stay the course through the period. Winds have decreased
and will stay below 10 kts at all terminals through Saturday
evening. Clear skies persist Saturday morning, but increasing clouds
associated with an incoming system will drop ceilings to 15-20 kft
in the evening. Light rain is also expected to occur at KYKM toward
the end of the period. 75


&&


PREV DISCUSSION... /issued 235 PM PDT Fri Oct 17 2025/

DISCUSSION...
Key Points....

1. Cold front through today bringing light rain and breezy gap winds

2. Brief dry period Friday night into Saturday afternoon

3. Upper level low and surface cold front Saturday night through
Monday morning will bring increased chances of precipitation and
winds.

4. Upper level ridging will return Monday afternoon and persist
through Thursday.

Rest of Today through Saturday afternoon...A wind advisory has
been issued for Kittitas Valley with current ground observations
already showing sustained winds over 30 mph and gusts to 40 mph
through the valley. Current satellite shows partly cloudy skies
across much of the region with some stratus lingering over the
Cascade crests and Blues. Ground observations as well as webcams
show the I-90 corridor receiving some light precipitation that
will continue through the majority of the afternoon and evening as
the front continues to push across.

Behind the cold front moving across the region, a dry air mas will
make its way across the region late this afternoon and early
evening. A weak ridge will build in behind drying out the region and
allowing winds to settle overnight and through much of Saturday.
Climate compare shows that the southern portion of the region,
mainly central/n central OR and portions of the Ochoco-John Day
Highlands will see above average temperatures (5-10 degrees) above
seasonal average while much of the WA portions will see temperatures
be at to below average (0 to -5 degrees). Raw ensembles show 70-90%
probabilities of central OR (Bend/Redmond/Madras/Prineville), John-
Day Basin and some isolated areas along the foothills of the
southern and northern Blues will see temperatures in the mid to
upper 60 degrees while the mid elevations and much of the WA portion
of the zones will see temperatures in the upper 50 to low 60 degree
range. Winds will be light and variable as well.

Saturday afternoon, models as well as ensemble guidance show firm
agreement in the movement of the upper level low and surface cold
front off the northern coast making its way across the region. This
system will bring increased chances of precipitation and high
mountain snow. QPF amounts along the crests are expected to range
between 0.50-0.80 inches with 70-80% probabilities and the Blues and
Wallowas seeing between 0.30-0.50 inches. For the foothills and the
east slopes, 60-80% probabilities of those areas seeing between 0.10-
0.25 inches of precipitation and the remaining elevations seeing 0.01-
0.07 inches.

Model guidance also shows the surface cold front will tighten the
pressure gradients along the Cascades and the Northern Blues. These
areas will see elevated winds with NBM ensembles showing the Gorge,
Simcoe-Highlands in Klickitat County, foothills of the S. Blues
through Boardman & N. Blues around the Dayton area seeing 50% to 75%
probabilities of sustained winds near 25-30 mph and 25-45%
probabilities gusts of 35 to 40 mph. Confidence in the issuance of a
wind advisory for the aforementioned areas for Sunday is moderate
(50-60%).

Monday through Thursday...Moderate to high confidence in the models
showing ridging moving back in over the region by Monday afternoon.
This will bring dry conditions and warmer temperatures through the
week. Models are in decent agreement with the movement of the trough
to the east and the ridge settling in behind. However, clusters show
a bit of a timing lag between the models. 90

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  35  63  45  61 /   0  10  50  70
ALW  39  62  48  61 /   0  10  70  80
PSC  33  60  47  64 /   0  10  50  40
YKM  34  57  40  61 /   0  10  60  40
HRI  35  61  47  64 /   0  10  40  50
ELN  31  53  36  58 /   0  20  80  40
RDM  28  71  41  58 /   0   0  20  40
LGD  31  65  45  58 /   0   0  40  80
GCD  31  69  45  59 /   0   0  20  40
DLS  40  63  48  64 /   0  10  70  70

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

SHORT TERM...90
LONG TERM....90
AVIATION...75