Pendleton, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

722
FXUS66 KPDT 062301
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
301 PM PST Fri Mar 6 2026

.KEY MESSAGES...

- Widespread breezy to windy conditions Sunday.

- Active weather continues next week, but significant
  uncertainty in forecast details remains.

&&

.DISCUSSION...
This afternoon through Saturday morning, another round of light
precipitation is forecast as a surge of moisture from the
Pacific wraps around the large offshore high and pushes inland.
While 12Z CAMs were quite aggressive with precipitation for the
mountains (Cascades and northern Blues), yielding totals of
several tenths of an inch to over an inch along the highest
terrain of the Washington Cascades and northern Blues, 18Z CAMs
have trended significantly downward, in line with output from
global ensemble NWP guidance and what would be expected in an
environment void of any strong frontal forcing. Thus,
confidence is high (80 percent) in lighter rain amounts of a
trace to a couple tenths of an inch for the lowlands, with
locally higher amounts for the mountains. Advection of warmer
air into the region has raised snow levels such that mountain
passes will likely (80 percent confidence) receive all rain.

Widespread breezy westerly winds are present this afternoon, but
not strong enough to warrant any wind headlines. Breezy to windy
westerly winds are forecast to persist through the majority of
the next seven days, with strongest winds currently forecast
Sunday and again mid/late next week.

Looking ahead, the 500-mb pattern is expected to turn zonal
over the weekend into next week. Precipitation chances taper off
Saturday east of the Cascade crest, but a moist zonal jet will
keep at least a chance (30-50 percent) of precipitation along
the Cascades through Sunday morning.

By late Sunday, clusters of like-solutioned ensemble members all
indicate a return to a more active weather pattern to the
forecast area. That said, there is still significant uncertainty
in pattern details. We are currently keeping a watch on
potential widespread windy conditions for the lowlands. The NBM
indicates high (70-90 percent) chances of advisory-level wind
gusts Sunday for the Kittitas Valley with medium-high (40-80
percent) chances elsewhere in the lower elevations. Will note
there is some potential (40-60 percent) for reaching High Wind
Warning thresholds (50 kt wind gusts) for the Kittitas Valley as
well. After isentropic analysis, have held off on issuing any
wind headlines for now due to uncertainty in timing/magnitude of
winds mixing to the surface. That said, all guidance is showing
a robust low-level jet of 35-55 kts around 850 mb through the
Cascade gaps and over the Columbia Basin and adjacent foothills.
Moreover, surface pressure differences of 10-15 mb between PDX
and GEG are advertised by current 12Z/18Z operational NWP
guidance, supportive of widespread advisory-level to perhaps
localized warning-level winds.

Jumping forward in time to late Tuesday through late Thursday,
the ECMWF EFI is signaling decent ensemble agreement (EFI values
of 0.5-0.9) for anomalous precipitation and snowfall relative
to model re-forecasts for the Cascades and their adjacent
eastern slopes. Shift of Tails (SoT) values of 2 show some
members are forecasting an extreme solution.

Taking a look at probabilities of snowfall amounts from the
NBM for the 48-hr period ending 00Z Friday, there is a 10-40
percent chance of reaching or exceeding 1 inch of snowfall for
the Kittitas and Grande Ronde valleys, with lower chances (up to
10 percent) for the Blue Mountain foothills and central/north-
central Oregon. The Oregon Cascade passes have a medium-high
(50-60 percent) chance of reaching or exceeding 6 inches of
snowfall, while the Washington Cascades have a high (80-90
percent) chance and the northern Blue Mountains have a low-
medium chance (10-50 percent). 86

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
VFR conditions continue through the TAF period, with mostly dry
conditions prevailing. A few stray showers are possible across
most of the sites, but not expecting any widespread or heavy
precipitation to dip levels below VFR for a prolonged period of
time. A 5-15% chance still exists for most sites for temporary
MVFR conditions to develop across areas expecting PROB30 rain
showers. Many sites outside of Central Oregon will continue to
see breezy conditions with 20-30 mph gusts for the whole 00Z
period. No other significant highlights will impact airport
terminals.

&&

.HYDROLOGY...
No flooding is currently forecast by the NWRFC for any of our
mainstem rivers. Would like to note that uncertainty in snow
levels, precipitation totals, and snow totals does indicate some
potential (30 percent confidence or less) for flooding along
rivers later next week if the right variables all align. This
potential may not be adequately captured in GEFS-driven
probabilistic output from the HEFS since the ECMWF ensemble is
significantly wetter than the GEFS, though the Canadian
ensemble is also significantly drier than the ECMWF ensemble.

Warmer, wetter solutions would favor increased rises along
rivers, while cooler, snowier solutions and/or those with less
precipitation would keep river levels lower. 12Z global ensemble
clusters show a roughly 60-40 split among ensemble members in
favor of cooler solutions, though there is more nuance to
precipitation solutions. Roughly 30 percent of members show
multiple inches of precipitation along the Washington Cascades
with significant spillover (up to a couple inches) into the
east side valleys, while roughly half of members keep more
modest precipitation totals across the entire forecast area
(still heaviest for the Cascades) and the remaining 20 percent
keep drier conditions across most of eastern Oregon and eastern
Washington with notable precipitation (more than a few tenths of
an inch) confined to the Washington Cascades. 86

&&

.Preliminary Point Temps/PoPs...
PDT  45  64  43  62 /  50  10   0  10
ALW  46  64  47  62 /  60  20   0  20
PSC  45  69  47  65 /  40  10   0   0
YKM  42  66  40  62 /  30  10   0  20
HRI  46  67  46  65 /  40  10   0   0
ELN  42  58  42  54 /  40  10  10  40
RDM  35  62  33  60 /  30   0   0   0
LGD  41  61  39  61 /  70  30  10  10
GCD  38  58  35  60 /  50  20   0   0
DLS  46  62  45  59 /  50  10   0  40

&&

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

&&

$$

DISCUSSION...86
AVIATION...95
HYDROLOGY...86