668
FXUS66 KPDT 041148 CCA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
447 AM PDT Thu Jun 4 2026

.KEY MESSAGES...

- Breezy winds developing in the Simcoe Highlands, Columbia River
  Gorge and Kittitas Valley Today, with winds peaking Friday.

- Cooling trend through Saturday with weekend Cascades rain.

- More widespread rain showers Monday int Tuesday.


&&

.DISCUSSION...

The synoptic setup features and eastward moving/exiting
shortwave in advance of eastern pacific upper low that will dive
southeast toward the BC/WA coast through Friday night. In the
meantime for Thursday, a broad upper weakly diffluent flow will
be in place with dry weather across the Columbia Basin and
Mountain zones.

Breezy winds through the mountain gaps can be expected to
increase over the next couple of days as the aforementioned
upper low spreads to the PAC NW coast by Friday evening,
bringing a marine push and frontal passage into the interior for
Saturday. The Breezy winds today will be largely relegated tot
he Kittitas valley and the eastern Columbia River Gorge/Lower
Columbia Basin. Those conditions become more windy by Friday
afternoon with sustained speeds though the Gorge on the order of
20- to 25 mph and higher gusts in the 30 to 40 mph range across
the Simcoe Highlands and Columbia Basin of Oregon.

A secondary upper cold core low is shown by the EC/Canadian and
GFS models to impact the region Monday night into Wednesday
bringing opportunity for cloudy, cooler as well as more wet
weather even for the Basin area and eastern Mountains.
Russell/71

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...

Primarily westerly  winds across the area Today with eh strongest
winds through the Gaps. DLS will have the most robust wind speeds up
to 15-20 knots and gusts up to around 20-35 knots in the afternoon.
Much lighter winds elsewhere with VFR flight conditions anticipated
across all terminals. Russell/71

&&

.FIRE WEATHER...

Thursday and Friday pose elevated fire weather risk in the
Columbia Basin as winds pick up leading to combined
probabilities for low RH and strong winds. Combines probs of
of 25% and 15 mph are between 30 and 70% across the Oregon
Basin zones Today and the Washington Columbia Basin area on
Friday. Chances for wetting rains increase to a 20-80% range by
Saturday Night across the Cascades eastern slopes to the crest.
As the upper low makes it way across the region over the
weekend, a dry period on Sunday is anticipated. Another Upper
low in the models digs farther south across the Interior Monday
night spreading high wetting rain chances across the Cascades
Crest (80%) and Eastern Slopes (30-65%). The eastern mountains
will have similar chances for wetting rains but with a slight
time lag into the Tuesday night time window on a 24 hour basis.
Russell/71

&&

.Preliminary Point Temps/PoPs...
PDT  75  47  72  45 /   0   0   0   0
ALW  76  52  74  50 /   0   0   0   0
PSC  80  50  77  47 /   0   0   0   0
YKM  80  47  74  43 /   0   0   0   0
HRI  78  50  74  45 /   0   0   0   0
ELN  71  44  66  38 /   0   0   0   0
RDM  76  39  73  36 /   0   0   0   0
LGD  74  43  75  43 /   0   0   0   0
GCD  77  42  80  40 /   0   0   0   0
DLS  77  52  71  48 /   0   0   0   0

&&

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

&&

$$

DISCUSSION...71
AVIATION...71
FIRE WEATHER...71