869
FXUS66 KPDT 300950
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
250 AM PDT Fri Oct 30 2026

.KEY MESSAGES...

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

- Periodic showers today, mainly along the Cascade crest.
  Medium-high (30-70%) chance of precipitation for
  central/eastern Oregon and southeast Washington over the
  weekend.

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

&&

.DISCUSSION...
Not too much of a change in satellite imagery since yesterday`s
discussion. Water vapor imagery shows a large, quasi-stationary
low-pressure system located just offshore of the Pacific
Northwest. Middle and high cloud cover has increased since
yesterday, and this appears to have helped put a damper on
notable fog formation early this morning. Radar reveals little
in the way of returns over the forecast area.

Ensemble NWP guidance is in excellent agreement that a shortwave
currently visible just off the southwest Oregon coast will
round the aforementioned upper-level low later this morning and
induce low chances (30% or lower) of showers for the Oregon
Cascade crest and medium chances (30-70%) of showers for the
Washington Cascades. Farther east, dry conditions are forecast.

Over the weekend, the low is expected (95% confidence) to
transition to an open-wave trough and move inland. While
chances of precipitation have trended downward slightly, they
are still medium-high (30-70%) across the majority of
central/eastern Oregon and southeast Washington Saturday
afternoon through Sunday morning. The best chance of significant
precipitation will be over Wallowa County where the NBM places
a 30-60% chance of 0.25" and 10-30% chance of 0.50" of QPF
through Sunday.

Ensemble solutions are coming into a better concensus with
regard to when the trough will exit to the east and upper-
level ridging will build in from the Pacific; specifically,
ensemble means suggest the trough will slide east late Sunday
afternoon into Sunday night, and an amplified upper-level ridge
will be overhead by Monday morning. Given clearing skies and
dry conditions, this presents the best chance, albeit low at
30% or less, of a season-ending freeze for the eastern Columbia
River Gorge. Freeze-prone portions of the Gorge do have
somewhat higher chances of freezing, but at this time confidence
remains too low to issue any watches.

Uncertainty in the 500-hPa pattern then grows Tuesday through
the remainder of the week. Aside from a very low chance (5-15%)
of precipitation on Tuesday, mostly dry conditions are forecast
to continue until Thursday when ensemble guidance hints at the
return of some more active weather. Even then, chances of
precipitation remain low (40% or less, highest for the
Cascades).

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
VFR conditions to prevail through the period. Short-term model
guidance shows MVFR CIGS redeveloping at sites DLS/RDM/BDN again
tonight, but confidence is low (20-25%) in CIGs lowering below
3kft AGL. For now, have left a 3.5kft broken CIG at DLS, with a
scattered 3kft at RDM/BDN. Winds will be light, 12kts or less,
through the period. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  49  33  48  33 /   0   0   0  30
ALW  50  36  49  37 /   0   0  10  40
PSC  54  31  52  33 /   0   0   0  20
YKM  53  31  52  32 /  10  10   0  10
HRI  52  31  49  32 /   0   0   0  30
ELN  49  23  48  25 /  20   0  10  20
RDM  50  24  46  23 /   0   0  20  40
LGD  57  32  55  35 /   0   0  30  40
GCD  57  34  55  35 /   0   0  20  40
DLS  55  33  53  35 /  20  10   0  30

&&

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

&&

$$

DISCUSSION...86
AVIATION...82