668
FXUS66 KPDT 172321
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
421 PM PDT Sun May 17 2026

.KEY MESSAGES...
- Scattered rain and snow showers and slight chance (10-15
  percent) of thunder over Wallowa County today. Very low (5-10
  percent) chance of showers and thunder elsewhere.

- Mostly dry and warming conditions region-wide Monday through
  Saturday.

&&

.DISCUSSION...
Scattered rain and snow showers are ongoing across Wallowa
County this afternoon as an upper-level trough digs southeast
over the Great Basin, placing the Pacific Northwest under a
cool northerly flow aloft. Through afternoon, there are low
(10-15 percent) chances of thunder for Wallowa County, but have
yet to observe any convection deep enough to produce lightning.
Elsewhere, there are low (5-10 percent) chances of rain showers
and thunder across the Washington Cascades and portions of
south-central Washington and far northern Oregon.

Monday through Saturday, warming temperatures and mostly dry
conditions are forecast region-wide as an upper-level ridge of
high pressure will likely (90-95 percent chance) build into the
region from the Pacific and dominate the weather. A couple weak
shortwaves passing through northwesterly flow aloft may
facilitate some isolated showers for the mountains, but PoPs are
low (generally 5-10 percent, except 15-35 percent for the
northern Blues and Wallowa County on Monday).

Breezy westerly winds are forecast through the Cascade gaps each
day of the week, but not anticipating a need for any wind
headlines. Thursday and Saturday have the highest chances
(10-40 percent, and 20-60 percent, respectively) of reaching
advisory-level winds through wind-prone areas of the lower
elevations, primarily the eastern Columbia River Gorge, north-
central Oregon, the foothills of the Blue Mountains, and the
Kittitas Valley.

The alternate, less-likely scenario (a closed low from Canada,
with cool, showery weather between Wednesday and Thursday) from
yesterday`s discussion appears to have almost entirely dropped
out of the ensemble envelope of solutions and does not appear in
any cluster of ensemble solutions.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
VFR conditions prevail going through the next 24-hours. Not
expecting any CIG or VIS issues at any sites. Winds will be
slightly breezy in the DLS tomorrow afternoon with 15-25 knot
gusts developing.


&&

.Preliminary Point Temps/PoPs...
PDT  39  69  42  72 /   0   0   0   0
ALW  43  69  46  72 /   0   0   0   0
PSC  42  75  45  77 /   0   0   0   0
YKM  42  74  44  77 /   0   0   0   0
HRI  41  73  44  76 /   0   0   0   0
ELN  39  68  40  70 /  10  10  10   0
RDM  29  68  31  73 /   0   0   0   0
LGD  33  64  36  69 /   0   0   0   0
GCD  30  65  34  71 /   0   0   0   0
DLS  44  73  45  75 /   0   0  10   0

&&

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

&&

$$

DISCUSSION...86
AVIATION...95