823
FXUS66 KPDT 222314
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
414 PM PDT Sun Jun 22 2025
.UPDATED AVIATION DISCUSSION...
.AVIATION...00Z TAFs...VFR conditions prevail through this period
with skies gradually clearing. KDLS may have gusty winds up to
25kts during this evening before decreasing tonight. KYKM could
have light showers for this evening, but confidence is low
(<20%). Otherwise, winds will be less than 12kts for the remaining
sites with no expected precip. Feaster/97
&&
.PREV DISCUSSION... /issued 108 PM PDT Sun Jun 22 2025/
SHORT TERM...Today through Tuesday...Satellite imagery this
afternoon reveals a center of low pressure circulation over the
Montana/Idaho border. This low will continue to bring mild
conditions to the forecast area, along with some residual wrap-
around moisture, primarily to the eastern mountains and the
foothills of the WA Cascades. Models have backed off on storm
chances, given the ongoing cloud cover across both areas, but CAMs
such as the HRRR are still keying in on at least some isolated
shower activity this afternoon. Dialed back PoPs some, but otherwise
expecting dry conditions to prevail by nightfall.
Heading into the work week, temperatures will start to rebound as
the cold air from the aforementioned low exits the region and a more
progressive, zonal pattern takes its place. Models have temperatures
creeping back up into the 90s across the lowlands by Tuesday as mid-
level flow develops a bit of a SW component to it, however dry
conditions are expected to prevail, as a deepening trough over the
Great Basin will allow a dry air mass to prevail overhead. RHs will
be at their lowest on Tuesday as a result, but until the pattern
truly develops its zonal feature as expected by the midweek, winds
will be relatively light outside of the Cascade Gaps, thus limiting
any critical fire weather conditions. Evans/74
LONG TERM...Wednesday through Sunday...Temperatures will start to
modulate back toward more seasonable readings by Wednesday as the
synoptic pattern shifts toward that of a progressive zonal one. The
midweek starts out with an open trough that will invite an uptick in
winds across the forecast area, as well as cooler temps as it swings
a cold front through the CWA. This trough looks to be the only
significant feature of the long term, however, as the rest of the
period looks to be dominated by a mix of zonal flow and weaker
shortwaves through at least next weekend.
While NBM probabilistic suggests a 60-70% chance for wind gusts in
the Cascade Gaps to exceed 35 mph, and up to 30 mph in the Basin,
the marine push offered by this trough, as well as the cooler temps
brought in from behind the cold front, are expected to keep RHs
elevated (generally bottoming out in the mid to upper 20s) enough to
preclude critical conditions. That`s not to say that these gusty
winds won`t lead to an enhanced fire spread risk, but the RHs are
not expected to be low enough to support truly explosive wildfire
behavior. This pattern will also support some low-end chances for
showers (20-30%) across the Washington Cascades, as the upper-level
winds favor at least some slight orographic enhancement.
Beyond Wednesday, this progressive pattern will continue to invite
breezy conditions through the Cascade Gaps, but high temps are
expected to cap out in the upper 70s to mid 80s in the absence of
high pressure or warm air advection. Ensemble guidance suggests that
this could change next weekend, however, with the introduction of a
ridge, which could invite hot and dry conditions back into the
forecast area (40-50% confidence). Evans/74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 49 85 54 92 / 0 0 0 0
ALW 54 83 58 91 / 10 0 0 0
PSC 52 87 54 94 / 0 0 0 0
YKM 51 85 56 90 / 10 10 0 0
HRI 51 87 55 94 / 0 0 0 0
ELN 52 84 55 88 / 0 10 0 0
RDM 37 82 44 87 / 0 0 0 0
LGD 43 78 48 86 / 0 0 0 0
GCD 41 80 48 87 / 0 0 0 0
DLS 54 86 59 88 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...74
LONG TERM....74
AVIATION...97
