861 
FXUS66 KPDT 302320
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
420 PM PDT Sat Aug 30 2025

.UPDATED AVIATION.

.AVIATION...00Z TAFs...VFR conditions linger around the area. Some
smoke and haze still linger in PDT but far away enough to not drop
levels to MVFR. No precip expected with winds remaining light and
variable.

&&

.PREV DISCUSSION... /issued 125 PM PDT Sat Aug 30 2025/ 

DISCUSSION...A relatively complex synoptic pattern is setting up
for the Pacific Northwest for the next week. Satellite imagery 
currently shows a broad low pressure system circulating just off 
the coast. Models have this low meandering towards the Olympic 
Peninsula before retrograding during the week, leaving our 
forecast area caught between two deep troughs. A quasi-ridge 
pattern results, which will cause a distinct warm-up through the 
midweek. So long as this offshore low remains in our area of 
influence, however, expect mild gap flows and persistent chances 
for isolated showers and thunderstorms over at least the next 
several days.

Currently, radar shows some light shower and storm activity 
developing across Union and Wallowa County. CAMs are not too bullish 
on coverage this afternoon and evening, likely due to the low shear 
and subsidence aloft as weak ridging forms ahead of this offshore 
low, but the ingredients still remain for at least isolated activity 
for the area. Winds remain relatively light, however gap flows are 
picking up above guidance for The Dalles this afternoon, suggesting 
a stronger cross-Cascade gradient than what models are picking up on 
(which makes sense. There is a low offshore after all). Expect mild 
breezes downslope of the Cascades this afternoon as well as 
tomorrow, combining with low RHs to make for elevated fire weather 
concerns. Don't think winds will be strong nor widespread enough to 
warrant any headlines, but active incidents (like the Flat Fire) 
will certainly be affected by these conditions.

Favorable ascent then shifts to the central Washington Cascades for 
tomorrow, albeit only enough to support slight (15-20%) chances for 
showers and thunderstorms. Focus then shifts to the building heat 
beyond Labor Day, but before then, this low looks to circulate a 
secondary trough from SoCal into the region Tuesday night into 
Wednesday. Models aren't depicting this system too cleanly as of 
yet, but will certainly be something to keep an eye on as the days 
progress. By then, the heat will really start ramping up, with 
decent probabilities (50-60%) for the lower Columbia Basin to see 
high temps eclipse 100 degrees, which would flirt with daily records 
given the time of year. Evans/74


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  63  94  61  94 /   0   0  10   0 
ALW  68  97  68  97 /   0   0  10   0 
PSC  62  97  62  96 /   0   0  10   0 
YKM  63  95  63  95 /  10  10  10   0 
HRI  62  96  63  96 /   0   0  10   0 
ELN  58  94  60  93 /  10  10  20   0 
RDM  51  92  50  93 /  10   0   0   0 
LGD  60  94  60  96 /  10   0   0   0 
GCD  61  95  60  97 /   0   0  10   0 
DLS  63  92  63  94 /  10   0  10   0 

&&

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

$$

SHORT TERM...74
LONG TERM....74
AVIATION...95