Kennewick, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

698
FXUS66 KPDT 200547
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1047 PM PDT Sat Jul 19 2025

Updated Aviation Discussion

AVIATION...06Z TAFs...Mostly VFR conditions to prevail through the
period. Smoke from regional fires has collected along the
foothills of the Blue Mountains this evening, resulting in site
ALW reporting a bkn-ovc CIG between 2.5kft to 3kft. This CIG is
expected to dissipate in the next few hours. Otherwise, few-sct
CIGS AOA 10kft-25kft AGL will impact sites through the period.
Breezy winds between 10-15kts with gusts to 20-25kts at site PDT
will weaken overnight, with light winds prevailing through the
period. Winds between 10-15kts with gusts around 21kts will
continue at site DLS, then increase 15-20kts with gusts around
25kts after 19Z. Otherwise, winds will be 12kts or less at all
other sites through the period. Lawhorn/82


PREV DISCUSSION... /issued 227 PM PDT Sat Jul 19 2025/

DISCUSSION...Tonight through Saturday...

Key Messages:

1. Heightened fire weather conditions through this evening.

2. Slight chance (~20%) of thunderstorms Monday and Tuesday.

3. Fire weather concerns return Wednesday through Friday.

Current radar and visible satellite imagery shows dry conditions
as mid-to high level clouds stream in across the Lower Columbia
Basin from the northwest. These are associated with a weak upper
level trough that will give way to a stronger system that
approaches Sunday, before passing through the Pacific Northwest
Monday into Tuesday morning. A surface low pressure has dropped
into southeastern Washington this morning, which has allowed a
pressure gradient to develop along the Cascades. This pressure
gradient has allowed for breezy winds to occur through the Gorge,
Lower Columbia Basin of Oregon, Blue Mountain foothills, and the
Kittitas Valley as gusts of between 25 and 35 mph are currently
being observed. Even though conditions are cooler than on Friday,
humidities are nearing critical fire weather thresholds in the
aforementioned areas as values hover around 20%. Conditions will
improve this evening as overnight humidity recoveries will
increase into the good to excellent range (>55%) for much of the
region, but lower lying areas of the Gorge, Blue Mountain
foothills, Hanford area, and the Yakima Valley may only experience
moderate (40-50%) recoveries into Sunday morning. The approaching
upper level trough will dig along the coast on Sunday, tapping
into additional moisture from lower latitudes as afternoon
humidities improve slightly on Sunday ahead of a much more
substantial increase on Monday. The pressure gradient will also
relax on Sunday to allow for lower wind speeds, but still breezy
through the afternoon and early evening for the Gorge and Simcoe
Highlands.

The incoming system will dig along the coast on Sunday and begin
to erode the upper level ridge located to our east on Monday. This
will bring a slight chance (15-25%) of showers across the eastern
mountains and portions of the John Day Basin Sunday evening after
5 PM. These chances will trend upward (40-55%) overnight and into
Monday morning, extending across much of the area with higher
chances (30-40%) along the eastern mountains, Blue Mountain
foothills, and the east slopes of the Washington Cascades. Rain
chances will push north and east after 5 PM, with only a slight
chance (15-25%) of showers lingering across the east slopes of
the Washington Cascades and Wallowa County. Rain amounts late
Sunday through Monday are expected to reach around a wetting rain
(0.10") along the Blue Mountain foothills and Kittitas Valley,
with higher amounts of 0.15-0.25" along the east slopes of the
Washington Cascades and east of the northern Blue Mountains.
Ensemble members are also picking up on the potential (15-25%
chance) for isolated thunderstorms to develop across
Central/Eastern Oregon and the east slopes of the Washington
Cascades as the system passes and interacts with the upper level
ridge. Best storm chances will align with the peak heating of the
day, between 2 PM and 5 PM. Main storm concerns revolve around
gusty and erratic winds associated with any developing cells, as
well as new fire starts outside the rain core. The system exits
the area to the east on Tuesday, with a slight chance (15-25%) of
afternoon showers and isolated thunderstorms lingering along the
east slopes of the Washington Cascades.

58% of ensemble clusters are showing a cut-off low developing
offshore of the northern California coast on Wednesday, which
would attribute to drier and warmer conditions across our area.
This low pressure looks to slowly track north Thursday before
passing through southern and central Oregon Friday, with 67% of
ensemble members in agreement. This will bring a period of warm,
dry, and breezy conditions across the area Wednesday through
Friday. At this time, critical Red Flag conditions are not
forecast to be met, but some areas in the Kittitas Valley and the
east slopes of the Oregon Cascades do approach these values
Thursday and Friday. 75

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  60  84  60  84 /   0  10  20  30
ALW  63  83  64  83 /   0   0  20  40
PSC  58  85  61  84 /   0   0  10  20
YKM  58  85  60  81 /   0  10  10  40
HRI  60  86  62  86 /   0   0  10  20
ELN  57  84  58  79 /   0  10  10  40
RDM  48  84  50  79 /   0  10  10  20
LGD  57  82  58  78 /   0  10  30  50
GCD  54  85  57  80 /   0  10  30  50
DLS  61  82  62  84 /   0  10  10  20

&&

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

$$

SHORT TERM...75
LONG TERM....75
AVIATION...82