704
FXUS66 KPDT 271815
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1015 AM PST Thu Nov 27 2025

Updated Aviation Discussion

.AVIATION...18Z TAFs...MVFR or lower conditions will prevail for
many sites through the period. A cold front passing through the
region is producing a band of light to moderate rain that is now
impacting sites PSC/PDT/ALW, with precip ending before 20Z. CIGs
for PDT/ALW are expected to improve to VFR after the rainfall
moves through, but there is a low chance (<10%) that CIGs stay
MVFR or lower after precip ends. Vsby will is also expected to
improve to MVFR or higher at both sites, but much like with CIGs,
there is a low chance (<15%) for CIGS to remain less than MVFR.
Sites DLS/YKM will remain at MVFR or lower conditions through the
period.

The next round of precipitation will arrive to the region after
1Z, with precip,vsby/cig impacts expected at sites
DLS/PDT/YKM/ALW/PSC through the end of the period. CIGs will drop
to less than MVFR at sites PDT/YKM/ALW/PSC as precip persists
through the overnight hours. Vsby is expected to drop to at least
MVFR at sites PDT/PSC/YKM, with IFR or lower at site ALW
overnight. Sites RDM/BDN will remain at VFR through the remainder
of the period, with no precip impacts expected (confidence
60-70%).

Winds will be light, 12kts or less, through the period, except at
sited BDN where winds will increase to 12-15kts with gusts up to
25kts between 20Z-02Z. Lawhorn/82


PREV DISCUSSION... /issued 312 AM PST Thu Nov 27 2025/

.DISCUSSION...

A pacific warm front was draped roughly along the Columbia River
overnight. Mid and higher level moisture lifting pole ward over
southern WA was exposing broad low level stratus and fog on the
the 10.3-3.9um GOES band. METARs and highway cams evidenced fairly
widespread dense fog across much of the central Oregon counties
into the foothills of the Blue Mountains. The dense fog advisory
was expanded to include additional areas long the northern blue
mountain foothills including Walla Walla. Impact from this fog
will include reduced visibility to less than one quarter of a mile
across much of these areas through around 18z, when the HREF
surface probabilities of vsby <1/2 and 1/4 mile fall form this
50-70% values this morning to the last lingering area of 15% or
so across Umatilla county by 10 am.

By midday the low pressure off the coast will be moving inland,
increasing pops across the WA and OR Cascades again to 80-95%.
This will lead to some additional light snow across the Washington
Cascade crest, Snoqualmie and White passes. while rain showers
farther south across the Columbia Gorge and OR cascades and around
0.05 mean rainfall across the Yakima and Kittitas valleys.
As the system progresses farther inland overnight, the eastern
mountains will likely pick up a few additional inches of snow.
The rest of the week is a relatively dry period for much of the
lowland areas. This weekend will be the coolest period of the next
7 days as highs will be relegated tot he upper 30s and lower 40s
and lows in the 20s. NBM range of outcomes show a slight
moderation to temperatures in the 40s and 50s for next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  46  36  44  29 /  60  90  90   0
ALW  45  38  44  31 /  70  90  90  10
PSC  45  36  49  29 /  80  90  60   0
YKM  43  36  49  29 /  90  90  40   0
HRI  45  37  47  29 /  70  90  80   0
ELN  40  32  45  26 /  90  90  30   0
RDM  55  31  50  26 /  20  30  20   0
LGD  48  36  44  27 /  40  80  90  10
GCD  53  34  46  28 /  20  30  60   0
DLS  48  41  51  37 /  90  90  70  10

&&

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

$$

SHORT TERM...71
LONG TERM....99
AVIATION...82