505
FXUS66 KPDT 112028
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
128 PM PDT Fri Jul 11 2025

.SHORT TERM...Today through Sunday...High pressure is starting to
build over the PacNW and is expected to last through early next
week. Temperatures will gradually trend upward as a result, peaking
on Sunday, with highs up to 105 degrees possible across the lower
Basin (20-25% chance). A Heat Advisory has been issued for Saturday
through Monday for the Basin, Gorge, Yakima/Kittitas Valleys, and
the foothills of the northern Blues. HeatRisk shows admittedly
marginal risk for advisory threshold heat Saturday and Monday, but
with highs wavering around 100 degrees, felt that it was necessary
to broadly advertise the heat through the whole weekend, even if
some days are technically borderline.

Only other concern with high pressure in place will be an uptick in
winds across the Cascade Gaps on Sunday, which will be primarily
thermally-driven. The Kittitas Valley, in particular, may see gusts
up to 40 mph on Sunday afternoon (60-70%). RHs as of now do not look
to reach critical levels, but fire risk will be elevated
nonetheless, given how hot and dry it will be over the weekend.
Evans/74

.LONG TERM...Monday through Friday...Models continue to exhibit a
fair amount of disagreement, especially beyond the midweek. One
feature of (relative) certainty is the arrival of a shortwave trough
to our northeast around Tuesday morning. As of now, guidance keeps
us dry from this system, however a slightly more southward track
could bring a chance of slight thunderstorms to the eastern
mountains. Winds are almost certain to shift more north and easterly
as a result of this system tracking as is currently projected, which
may complicate firefighting efforts for current and future
incidents.

Temps look to cool off by Wednesday, however forecast confidence is
low, as ensembles are divided in depicting the synoptic pattern,
differing between a benign zonal flow or bringing in a trough that
could spawn thunderstorms from central Oregon up through to the
eastern mountains. Will have to see how models evolve over
subsequent runs before speaking of the forecast beyond next
Wednesday with too much confidence. Evans/74

&&

.AVIATION...18z TAFs (Previous Discussion)...VFR conditions
expected, with clear skies and light, terrain-driven winds less than
12 kts prevailing across all sites. Evans/74


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  60  96  65 100 /   0   0   0   0
ALW  66  96  70 100 /   0   0   0   0
PSC  62  98  66 103 /   0   0   0   0
YKM  65  98  68 101 /   0   0   0   0
HRI  62  99  66 103 /   0   0   0   0
ELN  65  94  68  98 /   0   0   0   0
RDM  50  94  54  98 /   0   0   0   0
LGD  56  92  61  95 /   0   0   0   0
GCD  54  93  59  97 /   0   0   0   0
DLS  66  95  69 101 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from noon Saturday to 8 PM PDT Monday for ORZ041-
     044-507.

WA...Heat Advisory from noon Saturday to 8 PM PDT Monday for WAZ024-
     026>029.

&&

$$

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