181
FXUS66 KPDT 171103
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
403 AM PDT Thu Sep 17 2026

.KEY MESSAGES...

- |Isolated to scattered thunderstorm chances (15-30% chances)
  along the Blue Mountains and along the Foothills of the Blues
  through Friday.

- Slight warming trend, with high temperatures climbing into the
  mid to upper 80s through the weekend.

- Breezy winds along the Columbia Basin Friday, but will sit
  well below wind advisory criteria (70-80% chance).

&&

.DISCUSSION...
Current radar and satellite images advertise clear/high sky deck
with dry conditions in most of the area. An area of mid-level
moisture coupled with low radar returns is located across
Central Oregon near Bend and Redmond. This is a result of a
cut-off low pressure system with the center over the
California/Oregon border. This system will be the drive for our
weather over the next couple of days, bringing rain showers
across the Central Oregon through Wallowa`s region (50-70%
chances) with isolated to scattered thunderstorm development
occurring (15-30% chances) over the next 24 hours. As the low
progresses eastward, 250-500 J/kg of CAPE will develop, allowing
some storms to be pulsing and brief, with no anticipated severe
weather conditions expected (>90% confidence). The primary
concerns with any developing storm through Friday will be
frequent lightning, gusty outflows, and small hail. The
thunderstorm threat will pause going into Friday morning, with a
secondary peak going into Friday afternoon during peak heating
hours. Development will be mostly confined to the Wallowas and
parts of Grant county heading into the late Friday afternoon
time frame. Afterwards, guidance is in good agreement we`ll have
ridging taking over the pattern that will transition us into a
drier pattern through at least the beginning of next week
(70-80% chance).

With the onshore of the ridge into next week, a slight warming
trend bringing high temperatures into the mid to upper 80s will
occur through the weekend. As a result, we may see elevated fire
weather conditions re-develop with min RH`s dropping to the
20-30% range across most of the region. I don`t see critical
fire weather conditions developing as winds will be below
criteria thanks to the upper level ridge bringing mostly light
winds.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
VFR conditions persist with mostly dry conditions through the
overnight hours. Will see some showers move into the area,
especially at the sites in Central OR and along/near the
Foothills of the Blue Mountains. Greater PoP`s are located with
sites closer to the Blue Mountain area, with sites more in the
Basin (PSC/ALW) will only see PROB30 groups through the
afternoon hours. Otherwise, winds will generally be light with
most sustained winds less than 12 knots.

&&

.Preliminary Point Temps/PoPs...
PDT  71  51  76  50 /  20  60  10   0
ALW  72  56  77  55 /  30  50  10   0
PSC  78  52  81  50 /  10  20   0   0
YKM  79  51  79  51 /   0   0   0   0
HRI  75  52  80  50 /  10  40   0   0
ELN  77  50  75  49 /   0   0   0   0
RDM  65  40  75  38 /  70  40   0   0
LGD  72  48  73  46 /  60  60  40   0
GCD  69  48  73  46 /  70  70  40   0
DLS  84  58  81  53 /   0   0   0   0

&&

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

&&

$$

DISCUSSION...95
AVIATION...95