421
FXUS66 KPDT 102230
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
330 PM PDT Mon Aug 10 2026

.Updated Aviation Discussion.


.KEY MESSAGES...
1. Dry, warm and breezy conditions will persist through the weekend
   and beginning of the week

2. Pattern shift mid-week could bring precipitation and thunderstorm
 chances

&&

.DISCUSSION...
Current satellite shows mostly clear skies with smoke lingering in
some areas around the wildfires. Smoke will continue to linger
through the period but with the increased winds, will not settle to
heavily at the surface except overnight. AQAs are still in effect
for most counties except Sherman, Gilliam, Morrow and Umatilla and
will remain through at least Wednesday before being reevaluated.

Dry and warm conditions will persist through mid-week as westerly
flow aloft continues over the region. Westerly flow will continue
through mid week-with temperatures becoming slightly cooler. In
house calculations shows much of the region to still be above
seasonal average near 5 degrees above normal today. As the
temperatures begin to decrease, relative humidity will begin to
increase. This will bring the area out of critical fire weather
conditions but will still remain elevated. Winds are expected to
remain 10 to 15 mph and gusting between 25 to 35 mph through at
least tomorrow with 80% of the NBM raw ensembles in agreement.

Wednesday models show an upper level low beginning to slip into the
PacNW. This will bring southwest flow aloft as well as some mid
level moisture. Looking at NBM ensembles, there is a 15-20% chance
of the northern Cascades seeing thunderstorms. Looking at GFS
forecast soundings, there is MUCAPE values of between 250-500 J/kg ,
lapse rates of over 10 C/km, LIs of -2 and shear of 24 kts. These
storms will likely provide a strike or two as well as producing some
measurable rainfall.

Thursday appears to be a lull in activity before picking back up
Friday. Models show the region to be wedged between the upper level
trough to the north and the Four Corner high to the south. The high
will usher in some monsoonal moisture into central and eastern OR.
By Friday afternoon the moisture will be over central Or and the
eastern mountains with NBM ensembles showing 20-0% chances. As this
remains five days out, we will continue to monitor as the event
draws near.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
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 later this evening, extending through the
overnight period. Breezy winds will also persist for KDLS
through tonight, with sustained northwest winds of 10-20kts and
gusts of 20-30kts. 75

&&

.FIRE WEATHER...
Westerly flow has brought cooler temperature and increasing
relative humidity. While there are breezy conditions expected
across the region, especially through the Cascade Gaps and along
the southern Blue foothills, wind and relative humidity
thresholds are below critical. Fire weather remains elevated and
will remain elevated through the week.

Wednesday could see chances (15-20%) of thunderstorms along the
norther Cascades in Kittitas Valley. While we don`t expect them to
be strong in nature, we can not rule out a strike or two and gusty
outflows. As we move into Friday, models show monsoonal moisture
moving into the southern portion of the region through Deschutes,
Crook, Grant and Wallowa counties has 20-30% chances of seeing
thunderstorms. Otherwise the remainder of the region will be under
unstable conditions.

&&

.Preliminary Point Temps/PoPs...
PDT  53  88  54  84 /   0   0   0   0
ALW  60  89  60  86 /   0   0   0   0
PSC  56  91  57  89 /   0   0   0   0
YKM  58  92  59  88 /   0   0   0   0
HRI  57  90  58  87 /   0   0   0   0
ELN  55  85  55  82 /   0   0   0   0
RDM  46  88  45  84 /   0   0   0   0
LGD  52  90  53  87 /   0   0   0   0
GCD  52  92  52  89 /   0   0   0   0
DLS  60  88  61  83 /   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...90
AVIATION...75
FIRE WEATHER...90