Weather alerts for the NWS Pendleton OR forecast area

000
FXUS66 KPDT 281135
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
435 AM PDT Wed Oct 28 2026

.KEY MESSAGES...
- Moderate snow accumulations across the WA Cascades through
  this morning, with intermittent light mountain snow/rain
  through the weekend

- Breezy south to southwest winds today

- Below normal temperatures through the week

&&

.DISCUSSION...
Water vapor satellite imagery tonight shows an
upper closed low over Vancouver Island and southwest BC, while
the PacNW sits under a broad upper trough. Radar and nighttime
satellite imagery show rain/snow showers rounding the southern 
flank of the upper closed low into the WA Cascades. Elsewhere,
clear to partly cloudy conditions are present over the lower
elevations, with low stratus over portions of the eastern
mountains.

Today through Friday: The upper closed low just north of the
Olympic Peninsula will continue to guide light to moderate 
rain/snow showers into the WA Cascades the remainder of today,
with light rain/snow showers expanding across the OR Cascades
and northern Blues later this morning into the evening hours.
A cooler airmass associated with this low will continue to
filter into the region this morning, with snow levels lowering 
to around 3.5-4.5kft by sunrise. The increased shower activity
will bring snow accumulations of 3-7 inches above 4kft along 
the WA Cascades, with accumulations generally 1-3 inches above 
5kft in the OR Cascades, Elkhorn Crest, Eagle Caps, and interior
northern Blues(confidence 75-85%). A Winter Weather Advisory is
currently in effect for the Upper East Slopes of the WA 
Cascades through this afternoon.

Shower activity is expected to weaken and become intermittent
through Friday as the upper low remains parked offshore. Any
additional snow accumulations along the Cascade crest will be 
between 1-2 inches through Friday night (confidence 65-75%), 
with very low chances (5-15%) of a dusting (~0.1 inches) across
the remaining mountain zones.

Otherwise, a cooling trend associated with the upper closed low
will result in afternoon temperatures lowering into the 50s 
today, then lower further into the mid 40s to low 50s 
tomorrow and Friday (confidence 75-90%). Chances will increase
through the week for near to below freezing low temperatures
in the lower elevations, with best chances (75-95%) arriving 
Saturday morning. Freeze warnings may be needed by Saturday
morning for areas that have not received an area-wide season 
ending freeze. Breezy south to southwest winds (15-25mph with 
gusts to around 35mph) will continue to impact portions of 
central OR to the Columbia Basin today, with light winds 
returning later this evening.

Saturday through Tuesday: Ensemble guidance is in agreement of 
the upper closed low sliding inland Friday night into Saturday,
with continued chances of light rain/snow in the mountains 
through at least Saturday afternoon(confidence 60-75%). 
Saturday night into Sunday, the upper trough will push into the 
northern Rockies, allowing an upper level ridge to slide over 
the region Sunday through Monday with dry conditions (confidence
55-65%). After Monday afternoon, ensemble guidance is split 
into three scenarios. The first scenario is the upper level 
ridge gradually pushing east, but the PacNW remains under 
dry/calm conditions with a slight warming trend(~50% of Ensemble
cluster members). The second scenario is for a shortwave trough
to flatten the upper ridge as it moves across southern BC and 
northern WA, with a return of light mountain rain/snow across 
the Cascades and northern Blues Monday night into Tuesday (~30% 
of members). The last scenario is for an upper trough in the 
eastern Pacific to slide into the northern CA and southern OR, 
resulting in light shower activity along the Cascades and 
eastern mountains. Forecast confidence for early next week is 
low (10-15%) given the spread in ensemble forecast scenarios. 
Lawhorn/82

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...VFR conditions to
prevail through the period. An upper weather system to the north
will bring snow showers to the Cascades and interior Blues
throughout today, with prob30 chances of rain showers at site
PSC through 17Z, sites YKM/ALW through 21Z, and sites PDT/DLS 
through 01Z. Breezy winds 12-17kts with gusts to around 25kts
will develop at sites PDT/BDN/PSC through this afternoon.
Otherwise, winds will be around 12kts or less through the
period. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  54  32  52  31 /  30  10   0   0 
ALW  53  35  53  34 /  60  30   0   0 
PSC  59  30  54  31 /  10   0   0   0 
YKM  56  26  52  30 /  30   0   0  30 
HRI  57  30  52  30 /  20  10   0   0 
ELN  48  21  47  22 /  60  10   0  40 
RDM  49  20  48  21 /  10   0   0   0 
LGD  52  26  54  28 /  30  20   0   0 
GCD  51  25  55  29 /   0   0   0   0 
DLS  56  31  55  33 /  90  40   0  20 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 5 PM PDT this afternoon for 
     WAZ522.
OR...None.

&&

$$

DISCUSSION...82
AVIATION...82