159
FXUS66 KPDT 312130
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
230 PM PDT Sun May 31 2026

.KEY MESSAGES...

- Dry conditions with warming temperatures through midweek.
  Cooler thereafter.

- Mountain showers and thunderstorms return Wednesday into
  early Thursday, then possibly again over the weekend.

&&

.DISCUSSION...
An upper low remains over Montana with a larger trough over the
Pacific Northwest. Both of these features will remain in place
through Monday. By Tuesday, some weak ridging will move over
the Pacific Northwest. Due to the proximity of the trough, a
couple of passing showers can not be ruled out over far eastern
Oregon on Monday, but dry weather is generally expected.

On Wednesday, a trough and some shortwave energy will bring a
chance of showers and a low chance of thunderstorms (<20
percent), mainly to the mountains, which will linger into
Thursday. The trough moves out of the area by Friday, bringing a
return to dry weather. There will be some breezy winds with
this system on Wednesday into Thursday. NBM Probabilities of
wind gusts >=39 mph across the Columbia Basin, Gorge, and
Simcoe Highlands are generally in the 30 to 60 percent range.

By late Friday or early Saturday, an upper low, off the coast
will make its way inland and bring a renewed threat of showers
and thunderstorms, again mainly for the mountains.

There is still some uncertainty with the strength and location
of this low, and therefore what its ultimate impacts will be,
but we have 5 days to see how this play out. Depending on the
ultimate track, there could be some gusty winds Friday and/or
Saturday as well, especially for the Cascade Gaps, Simcoe
Highlands, Columbia Basin and Gorge and Blue Mountain Foothills.
NBM probabilities of wind gusts >= 39 mph are in the 30 to 70
percent Friday and 50 to 80 percent Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
VFR and dry weather conditions persist through the TAF period.
Winds remain fairly light and variable at less than 12 knots,
with the exception of the DLS experiencing 10 to 20 knots
through the afternoon hours.



&&

.Preliminary Point Temps/PoPs...
PDT  45  76  48  78 /   0   0   0   0
ALW  50  76  51  78 /   0   0   0   0
PSC  48  80  51  82 /   0   0   0   0
YKM  48  81  52  82 /   0   0   0   0
HRI  46  80  50  81 /   0   0   0   0
ELN  45  76  48  77 /   0   0   0   0
RDM  34  74  41  79 /   0   0   0   0
LGD  41  73  44  76 /   0   0   0   0
GCD  37  75  42  80 /   0   0   0   0
DLS  49  83  57  85 /   0   0   0   0

&&

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

&&

$$

DISCUSSION...77
AVIATION...95