025
FXUS66 KPDT 010537
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1037 PM PDT Sat Oct 31 2026

.KEY MESSAGES...
- Near- to below-normal temperatures into next week.

- Precipitation this evening into Sunday morning, mainly for
  eastern Oregon and far southeast Washington.

- Low chance (30% or less, except for freeze-prone areas) of a
  season-ending freeze for the eastern Columbia River Gorge
  Monday.

&&

.DISCUSSION...
Composite reflectivity showed a few showers popping off the NW
Blue Mountains of Washington, near Walla Walla as well as
elevated echoes over Franklin county early This Afternoon. Radar
returns were still sparse over the Oregon Cascades where
initial probabilities associated with the incoming synoptic
system for Tonight were found. Elsewhere, dense fog resulted in
limited visibility to a quarter mile or less during the morning
to early afternoon hours across the upper end of the Kittitas
valley, the Walla Walla Valley as well as the Foothills of the
Northern Blue Mountains. Based on mesonet observations and
roadcam networks, these areas have improved visibility to at
least 2 miles or better. REFS trends for precipitation Tonight
suggest around a tenth and up to a quarter of an inch of liquid
equivalent precipitation across the central Oregon
mountains/Oregon Cascades through about the middle of the
overnight hours. And meanwhile these trends have tended to
reduce QPF amounts in the last few days for the northern Blue
Mountains, where the mean QPF across the Blue Mountains and
Wallowas on average is up to a tenth of an inch (30 to 50%
confidence) with REFS QPF max amount over the Eagle Caps upwards
between a quarter and one half inch of liquid equivalent. Rain
snow mix is possible higher than 6500 ft, however the REFS only
offers about a half inch over the Oregon Cascade crest and one
to two inches on the Eagle Caps. Sunday ultimately winds up
being slightly warmer for parts of the forecast area like the
Yakima Valley, and Lower Columbia Basin with abundant insolation
and light westerly surface winds  and highs in the upper 50s
to low 60s in the Yakima and Columbia River Gorge.

The upper ridge develops Monday behind the exiting mid level
trough, redistributing the light westerly wind field to light
northeast across the Basin and potentially turning winds
southerly and breezy in the Grande Ronde Valley by Overnight
into Tuesday morning. Overnight low Temperatures through the
eastern Columbia River Gorge still appear mild and above
freezing over the next 7 day as to think at least at this time,
low confidence exists in any anticipated freeze headlines for
these last remaining last warning eligible zones, at least for
the first week of November.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...MVFR or lower
conditions expected to impact some sites through the period.
Short-term high-res guidance does indicate a return of CIGS AOB
2kft AGL at sites PDT/RDM/BDN/ALW tonight into tomorrow
afternoon. Wind shifts to the northwest at site PDT and shifts
to the south southwest at site ALW will coincide with lowering
CIGs. Confidence is low (15-20%) in vsby reductions occurring
at sites PDT/RDM/BDN/ALW throughout the night so have not
included in current TAFs. Otherwise, site PSC will see a CIG
reduction to around 3.5kft AGL overnight. VFR conditions to
prevail at sites DLS/YKM through the period. Winds will be
light, 12kts or less, through the period. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  34  53  31  57 /  20  20   0   0
ALW  38  52  35  56 /  40  20   0   0
PSC  33  59  30  56 /  10  10   0   0
YKM  32  60  29  55 /  10   0   0   0
HRI  32  57  31  56 /  10  10   0   0
ELN  27  56  25  52 /   0   0   0   0
RDM  25  51  21  57 /  20  10   0   0
LGD  36  52  29  56 /  30  30   0   0
GCD  35  50  30  58 /  20  10   0   0
DLS  36  60  33  57 /  10   0   0   0

&&

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

&&

$$

DISCUSSION...71
AVIATION...82