110
FXUS66 KPDT 101747
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1047 AM PDT Mon Aug 10 2026

.Updated Aviation Discussion.


.KEY MESSAGES...
- Dry and warm with diurnal breezes through Wednesday.

- An upper level trough will then move in followed by a return
  to southwesterly flow. Then there will be opportunities for
  mountain showers and thunderstorms for the end of the week.

&&

.DISCUSSION...
Dry westerly flow will continue over the Pacific Northwest for
the next several days. Breezy diurnal winds are anticipated,
with the Simcoe Highlands, Columbia Basin, Gorge and Kittitas
Valley having afternoon wind gusts in the 20 to 30 mph range,
possibly as high as 35 mph today and Tuesday, then decreasing a
bit on Wednesday.

NBM probabilities of wind gusts >=25 mph are >80 percent in
these areas today, and similar on Tuesday, though with slightly
less areal coverage. NBM probabilities of wind gusts >=39 mph
are 70-90 percent in the Kittitas Valley and generally less than
50 percent everywhere else.

High temperatures today will be similar to yesterday, perhaps a
degree or two cooler in some locations. Tuesday will be about
the same as today and Wednesday will be a couple of degrees
cooler. With the slightly lower temperatures by midweek, RH
values will increase a couple of percentage points today and a
few more going into Wednesday. This will help with fire weather
conditions, though they will still remain elevated.

By midweek, low pressure in British Columbia will move south and
push a trough into the Pacific Northwest. This low could
potentially trigger some light showers over the Washington
Cascades Wednesday, but not much more than that.

By Thursday, southwest flow will develop behind the departing
low and will strengthen into the weekend. There will also be
increasing monsoonal moisture specially Friday onward.

While it is too early to tell exactly how things will develop
this far out, there is definitely some potential (15-30%) for
mainly mountain showers and thunderstorms over central and
eastern Oregon.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
VFR conditions currently across all sites, which will stay the
course for most terminals through the period. KRDM/KBDN will be
the exception as smoke from nearby wildfires is expected to drop
visibilities the 5SM. Breezy winds are also anticipated for
KDLS/KPDT with gusts of 20-30kts through the afternoon. 75

&&

.Preliminary Point Temps/PoPs...
PDT  88  53  88  54 /   0   0   0   0
ALW  89  60  89  60 /   0   0   0   0
PSC  92  56  91  57 /   0   0   0   0
YKM  92  58  92  59 /   0   0   0   0
HRI  91  57  90  58 /   0   0   0   0
ELN  85  55  85  55 /   0   0   0   0
RDM  89  46  88  45 /   0   0   0   0
LGD  90  52  90  53 /   0   0   0   0
GCD  91  52  92  52 /   0   0   0   0
DLS  89  60  88  61 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...Air Quality Alert until 11 AM PDT Thursday for WAZ024-026>030-
     521>523.
OR...Air Quality Alert until noon PDT Wednesday for ORZ041-049-050-
     502-503-505-506-508>511.

&&

$$

DISCUSSION...77
AVIATION...75