242
FXUS66 KPDT 060515
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1015 PM PDT Sun Apr 5 2026

.KEY MESSAGES...
- Slight chances of thunderstorms Monday afternoon.

- Warm, seasonally above normal temperatures continue today and
  tomorrow.

- Breezy to windy conditions develop through the region Tuesday
  morning through late afternoon.

&&

.DISCUSSION...
An upper level ridge continues to settle in over the region
through tomorrow, allowing dry and warm conditions to continue through
much of the region. High temperatures will be seasonably warm
through Tuesday, climbing into the upper 70s and low 80s for
much of the lower valleys (>90% confidence). Although guidance
advertises dry conditions overall, HREF and REFS show paintball
clusters of >40 dbZ over Central Oregon through the Strawberry
Mountains and Wallowas initiating around 00Z Monday. With the
ridge breaking down and CAPE values climbing between 150 and
250 J/kg, chances of an isolated thunderstorm near Central
Oregon spanning to the Wallowa mountains have slightly increased
to 10-20 percent. Highest chances for a storm will be near late
afternoon through the early evening hours of Monday. Pea size
hail can`t be ruled out in some of these storms, with up to
penny size possible in the strongest cells.

A passing cold front will push through the area Tuesday
morning/early afternoon (>95% chance) and bring cooler high
temperatures and breezier winds in the region along with it.
Highs will drop to the low to high 60s in the lower elevation
areas and in the low to high 40s for higher elevations (70-90%
chance). Tight pressure gradients along with the front will
produce widespread breezy to locally windy conditions across the
region, bringing at least 20 to 30 mph gusts for much of the
area (60-80% chance). Stronger winds at the lower elevations is
currently expected in the Kittitas Valley and along the
Foothills of the Oregon Blues. NBM advertises about 20-30%
chances of advisory level gusts in Ellensburg, but increases to
60-80% chances just east of the city. Pendleton proper
advertises 30-50% chances, with the rest of the Foothills
ranging from 60-80% chances of at least 45 mph gusts. With a
strong 850mb jet absent in this set-up, confidence is not as
strong as it would to warrant a wind advisory yet. Will take a
look to see what trends set-up with the next run tonight and
assess whether an advisory is warranted for Tuesday.

Going further into mid to late this week, some uncertainty still
lies ahead with the oncoming low-pressure system moving
onshore. Around 40-50% of ensemble members initiate a set-up
suitable for thunderstorm development (namely along Central
Oregon and along the Blues) Thursday into Friday. The rest of
the members still bring light shower activity confined into
Central Oregon. This is dependent on the track of the low
pressure system, where a more northern approach will bring a
wetter/stormier pattern, while a southern track will split off
into the drier/warmer set-up.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
VFR conditions will prevail through Monday. Winds will generally
be 10 kts or less through Monday afternoon, then at DLS, RDM and
BDN, winds will gust to around 20 kts before decreasing during
the evening. All other sites will remain 10 kts or less.

&&

.Preliminary Point Temps/PoPs...
PDT  45  75  47  64 /   0   0   0   0
ALW  49  75  50  63 /   0   0   0   0
PSC  45  80  48  67 /   0   0   0   0
YKM  45  77  41  65 /   0   0   0   0
HRI  45  79  49  67 /   0   0   0   0
ELN  43  72  38  55 /   0   0  10   0
RDM  38  75  36  67 /   0   0   0   0
LGD  42  74  43  62 /   0  10   0   0
GCD  41  74  41  65 /   0  20  20   0
DLS  49  77  47  63 /   0   0   0   0

&&

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

&&

$$

DISCUSSION...95
AVIATION...77