967
FXUS66 KPDT 182147
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
247 PM PDT Tue Jun 18 2024

.SHORT TERM...Tonight through Thursday...The upper level trough over
the western USA remains in place with the current trough axis just
east of the forecast area. Some weak instability remains over the
forecast area today that is leading to some shallow convective
showers mainly over the eastern mountains and the east slopes of the
Washington Cascades. This includes a slight chance (15% or less) of
thunderstorms over the eastern mountains. These showers will
continue into the evening then dissipate towards sunset followed by
clearing skies.

The main energy in the upper level trough will continue to move east
over the next couple of days leaving a weak upper level trough over
the region Wednesday and Thursday. This translates to mostly clear
skies and light winds with temperatures continuing to warm each day.
High temperatures around the Columbia Basin will be in the 80s
Wednesday and then the upper 80s to lower 90s on Thursday while
mountains will see 70s Wednesday and 70s to low 80s Thursday.



.LONG TERM...Friday through Tuesday...

Key Messages:

1. Dry, warm conditions through Saturday

2. Breezy to locally windy conditions this weekend

A transient trough will be exiting the PacNW Friday allowing an
upper ridge to build over the region Saturday. Then, another trough
off the coast moves across PacNW Sunday, driven by a closed low
moving into British Columbia. Monday through Tuesday, the region
will then enter a zonal pattern before another weak upper level
trough off the coast puts us back under a southwest flow Tuesday
night. No chances of precip due to dry, warm conditions for the
extended period. Mountain showers are possible at the crest of WA
Cascades Sunday through Monday, but chance are low (<20%).

Breezy conditions for Yakima Valley, Simcoe Highlands, Foothills,
and Kittitas Valley will occur with wind gusts at 20-30 mph for
Saturday night into Sunday morning (>70% chance). However, wind
gusts could exceed to 40-45 mph Sunday afternoon into night for
these areas thus extending to portions of Columbia Basin. Sunday
confidence increases as surface pressure gradient strengthens with
the trough arriving from the backside of the transient ridge. Winds
will decrease first the week but breezy winds continue across the
forecast area with wind gusts at around 15-25 mph (40-50%
confidence).

High temperatures for Friday through Saturday will be above normal
in the low 90s around the Columbia Basin and mid to upper 80s for
the remaining forecast area. With the arrival of the upper level
trough on Sunday temperatures will cool by few degrees through
Monday before warming up again Tuesday. Feaster/97


&&

.AVIATION...18Z TAFS...All sites prevail at VFR for this period with
current clear skies and light winds. KPDT and KALW will have few
cumulus clouds passing through this afternoon and evening (40-50%
confidence). Feaster/97


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  46  83  51  88 /   0   0   0   0
ALW  49  86  54  91 /  10   0   0   0
PSC  50  87  56  93 /   0   0   0   0
YKM  49  84  55  89 /  10   0   0   0
HRI  50  89  54  94 /   0   0   0   0
ELN  48  80  52  85 /  10   0   0   0
RDM  41  82  47  84 /   0   0   0   0
LGD  42  78  48  84 /  20   0   0   0
GCD  43  81  49  86 /  10   0   0   0
DLS  53  88  59  92 /   0   0   0   0

&&

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

$$

SHORT TERM...91
LONG TERM....97
AVIATION...97