343
FXUS66 KPDT 090533
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1033 PM PDT Wed Oct 8 2025

Updated Aviation Discussion

.AVIATION...06Z TAFs...VFR conditions to prevail through the
period. A weak system lifting north across the Cascades will
produce scattered showers along the Cascade east slopes, with
prob30s at sites DLS/RDM/BDN between 8Z to 16Z, with otherwise
vicinity showers at those sites. Bkn-ovc CIGs will decrease to
around 5kft-6kft AGL at these sites with precipitation, but
confidence is low(20-25%) in MVFR CIGS or vsby developing with
precipitation. Winds will light, 12kts or less, through the period.
Lawhorn/82


&&

.PREV DISCUSSION... /issued 438 PM PDT Wed Oct 8 2025/

.DISCUSSION...

A cu field was developing across the higher elevation mountain
zones this afternoon. Some cirrus was also noted on visible
satellite as well Yakima and Kittitas counties, but the bulk
of the forecast area was sunny with light and variable surface
winds. Satellite looked too obscured by cloud to see hotspots
near the Labor Mountain and Wildcat fires, however the HRRR is
modeling increased vertically integrated smoke this afternoon and
evening with northward trajectories. Fire weather concerns are
greatest immediately east of the Cascades where the drier and
lower relative humidity areas of the Columbia basin will be This
afternoon and Thursday. Beyond Thursday, moisture profiles uptick
enough to minimize fire weather categories.

The eastward advancing upper low will induce a N-S band of
850-700 mb fgen and vertical motion which the 12kmNAM ramps up
after about 02z Thursday (This Evening). NBM probability for the
eastern slopes and crests of the cascades to see wetting rain
overnight are between 35 and 60%. Looking at the probability
matched means from the HREF 6 hour QPF does show a couple of
locations of favored 0.10-0.25 amount near the volcanoes, however
a more broad signal of much less than 0.10 qpf is anticipated.
This upper low will help focus showers across the Cascade range
and its eastern slopes through the week before moving onshore
late Friday into Friday night and spreading a more broad mid level
lift across the eastern mountains. NBM Ensembles 50th percentile
suggests 1 to 3 inches of snowfall possible across the Wallowas,
Northern Blue, Elkhorn, Aldrich and Strawberry Mountains, and
even higher amounts along the highest peaks of the Cascades. Along
with the precipitation will be an increase in breezy to
marginally windy conditions through the Gorge and Columbia Basin
on Friday night. True windy conditions are likely to develop late
Saturday and Saturday night across a more broad area into central
Oregon as well with gusts approaching 40 mph. A 40 to 60 percent
of gusts in excess of 40 mph are forecast by the NBM ensemble
member for the Oregon Columbia basin Saturday evening. Russell/71


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  44  72  46  70 /   0  10  10  20
ALW  49  73  50  71 /   0  10  20  30
PSC  42  73  45  72 /  10  10  10  20
YKM  47  72  50  70 /  30  30  20  40
HRI  42  73  45  71 /  10  10  10  20
ELN  41  70  44  66 /  40  40  20  40
RDM  39  65  38  63 /  40  40  20  50
LGD  44  77  45  76 /   0   0  10  20
GCD  46  75  45  72 /   0   0  10  10
DLS  49  70  50  68 /  60  60  30  50

&&

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

$$

DISCUSSION...71
AVIATION...82