Richland, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

707
FXUS66 KPDT 201756
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1056 AM PDT Sun Jul 20 2025

.Updated Aviation Discussion.


.AVIATION...18Z TAFS...VFR conditions currently across all sites,
which will stay the course through the period. Breezy winds will
persist across KDLS/KPDT with KRDM/KBDN joining in during the
afternoon as sustained winds of 10-15 kts with gusts of 20-25 kts
are expected. Winds will peak this afternoon, with the highest
values experienced at KDLS. Winds will subside overnight as 5-10kft
BKN/OVC ceilings move in from the northwest associated with an
approaching system. Showers will also be in the area for KRDM/KBDN
this evening and KDLS/KPDT/KALW toward the end of the period. 75


&&

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  84  60  81  58 /  10  30  30  10
ALW  84  64  79  61 /  10  20  40  20
PSC  85  61  81  59 /   0  10  20  10
YKM  84  62  79  58 /  10  20  40  10
HRI  86  62  83  58 /   0  20  20  10
ELN  83  59  78  58 /  10  20  40  10
RDM  83  49  80  46 /  10  20  10   0
LGD  82  57  76  51 /  10  40  60  20
GCD  84  56  79  51 /  10  40  50  10
DLS  82  62  85  61 /  10  10  20   0

&&

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

$$

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