653
FXUS66 KPDT 151734
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
934 AM PST Sat Nov 15 2025

.UPDATED AVIATION.

.AVIATION...18Z TAFs...VFR conditions mostly prevail in the first
half of the period. There is a concern for some low decks heading
into tomorrow morning with DLS/PDT/YKM potentially reaching MVFR
or even IFR conditions. Guidance suggest cloud deck levels to
lower to around 500 to 1500 feet by 12Z tomorrow morning.
Currently not showing strong signal support for a group, but will
leave TAFs showing around 3500 feet until confidence increases.
DLS has been given a MVFR group at 12Z and YKM, but all other
sites mentioned for potential low ceiling currently stand at a
5-15% chance of receiving sub-VFR conditions tomorrow morning.
Guidance will become more clear by the 06Z TAF report, but it`s
something to monitor going through today. Otherwise, winds are
mostly light and variable with most sites reporting <12 mph,
except for PSC which is reporting 10-15 mph (with a 5-15% chance
for a possible gust of 20-25 mph through the day).

&&

.PREV DISCUSSION... /issued 328 AM PST Sat Nov 15 2025/


DISCUSSION...

Cross barrier flow continues bringing lift across the Washington
Cascades this morning as a slug of mid level warm advection
across the Interior Northwest is lagged by a 925-850 mb moisture
transport signal west of the mountains. Composite radar is showing
the PDT area dry while thicker mid level clouds were moving across
the WA portion for the Columbia Basin. Light to breezy southwest
surface winds overnight will wane Today as high pressure
ridging/subsidence leads to lighter and more variable surface
winds. The warmest temperatures of the week are expected this
afternoon, as the Columbia Basin reaches the low to mid 60s.

The next piece of IVT (rather weak based on GFS/ECMWF) brushes
the Pac NW Sunday through Sunday night, spreading rain chances
across the entire area. Best rain chances (60-80%) across the
Kittitas valley and points nw of Ellensburg as will as the
Cascades Crest as well as the eastern mountains. A muted repeat on
Monday is possible (50-70%), again only in the higher elevations.
Temperatures will moderate into the low 50s over the Columbia
Basin Sunday and Monday afternoons. Rain chances will continue
though the week in the highest elevations of the cascades (20-30%)
with a more notable wet period possibly returning by Wednesday
and Wednesday night as low land areas see precipitation
probabilities increase to 45-60% per the NBM mean. The
opportunity for widespread hazardous weather is low through the
next 7 days.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  62  41  54  42 /  20  10  40  70
ALW  62  44  53  46 /  30  10  50  80
PSC  64  43  55  43 /  10  10  20  40
YKM  62  43  58  42 /  10  20  20  30
HRI  63  42  54  44 /  10  10  30  50
ELN  57  42  54  40 /  20  30  30  50
RDM  60  35  57  36 /   0   0  20  50
LGD  59  39  55  42 /  20  10  70  90
GCD  61  41  55  41 /  10  10  70  80
DLS  61  46  57  47 /  20  10  30  70

&&

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

$$

SHORT TERM...71
LONG TERM....71
AVIATION...95