507
FXUS66 KPDT 040539
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
939 PM PST Tue Nov 3 2026

.KEY MESSAGES...
- Light showers prevail through the afternoon in the Basin into
  the Yakima/Kittitas Valley.

- Mostly dry conditions continue Wednesday and later through the
  day.

- Active weather with breezy winds through the late part of the
  week and into next week.

&&

.DISCUSSION...
Radar currently advertises light precip across the Columbia
Basin into the Yakima/Kittitas Valley that will continue through
the afternoon hours. Soundings from OTX taken at 12z show lower
level dry air, which will allow little precip to accumulate out
of this system. PoPs are tapered up to 15% through the general
populated areas north of the Blue Mountains.

Area of low pressure is located right off the coast of
California and is expected to move inland (>90% confidence) over
southern Oregon and northern California over the next few hours.
Rain chances continue to be low (<20% chance) through late
Wednesday, but conditions remain mostly dry with ridging
developing just north in British Columbia. Ridging will keep the
weather dry and slightly warmer going through late Wednesday,
but guidance is in great agreement that a shortwave from the
Pacific will move inland by late Wednesday/early Thursday. Light
precip and locally breezy winds develop with the passage,
otherwise not expecting mush of any impacts from this system
(50-70% chance).

Looking towards the weekend, EURO and GFS members are hinting of
another weather system with a shortwave embedded pushing along
the area with periods of high PoPs (50-70% chances) along the
Cascades with lower chances (10-30% chances) across east of the
Cascades and into the populated centers across the rest of the
CWA. That shortwave will then push north and northeastward into
Canada by early next week (50-70% confidence), with another
system right behind located in the Pacific. Guidance gets shaky
after Sunday/Monday with guidance struggling with the
strength and timing of the second shortwave. GFS members favors
a stronger/wetter system, while Euro members trend towards a
weaker/drier system. At this point not seeing meaningful
impacts currently, as IVT values are currently <250 kg/ms
through Monday. Still plenty of time to monitor for this
evolving forecast incase the set-up changes.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...MVFR or lower
conditions to impact most sites through tonight, otherwise VFR
conditions expected to prevail after 17Z. Sites DLS/RDM/BDN are
already seeing either low CIGs or low vsby impact the sites
tonight. VSBY 1SM or lower is expected to develop at sites
RDM/BDN with CIGS down to 300ft tonight, then clear after 15Z.
Site DLS is expected to see vsby remain around 3SM through 17Z.
VSBY at sites PDT/YKM are expected to deteriorate to around 3SM
after 08Z, with 1SM or lower developing at site PDT around 11Z.
Short-term guidance tonight is favoring intermittent MVFR vsby
developing at site PSC between 11Z-15Z tomorrow morning, so have
included in the TAF tonight. Site ALW is expected to remain VFR
through the overnight period, but short-term guidance does
indicate a chance (30-40%) of low vsby/CIGs developing around
the Walla Walla valley overnight. Winds will be light, 12kts or
less, through the period. Lawhorn/82


&&

.Preliminary Point Temps/PoPs...
PDT  31  52  37  56 /   0   0  50  30
ALW  35  51  40  54 /   0   0  50  40
PSC  31  53  35  59 /   0   0  40  20
YKM  32  54  35  59 /  20   0  30   0
HRI  29  53  36  59 /   0   0  50  20
ELN  27  51  30  53 /  10   0  50   0
RDM  22  57  30  53 /   0   0  20   0
LGD  31  57  34  54 /   0   0  20  50
GCD  31  58  35  53 /   0   0  20  20
DLS  35  55  40  60 /   0   0  50  10

&&

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

&&

$$

DISCUSSION...95
AVIATION...82