644
FXUS66 KPQR 300547 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1047 PM PDT Tue Sep 29 2026

Updated aviation discussion.

&&

.SYNOPSIS...A frontal system continues impacting the region
with gusty winds and showers for far northern Oregon and SW
Washington. Dry weather is favored again by Wednesday, likely
lasting into early next week with temperatures trending warmer
day to day.

&&

.DISCUSSION...Tuesday afternoon through Monday...A frontal
system continues moving southeast toward SW WA and NW OR this
afternoon. Gusty winds with gusts up to 25-35 mph have been
observed this morning and will continue through this afternoon,
mainly for the coast north of Lincoln County and adjacent
terrain as well as for the far northern OR Cascades. Showers are
also occurring in the same area and portions of the SW WA
lowlands north of the Vancouver metro. As the cold front moves
inland this evening, winds and showers will quickly decrease.

Ensemble members are in very good agreement through the weekend
that dry weather returns on Wednesday and will continue through
at least Sunday. High pressure over the eastern Pacific will
move inland over the next few days then peak over the PacNW on
Saturday and Sunday. This will lead to a warming trend for the
area through the week. Temperatures tomorrow will be a few
degrees warmer than today for locations that see cloud cover
today, with another few degrees of warming for Thursday. The
interior lowland are expected see temperatures in the low to
mid 70s tomorrow and the mid to upper 70s for Thursday and
Friday. Temperatures then warm to the upper 70s to low 80s for
Saturday and Sunday for the interior lowlands, with upper 60s to
low 70s along the coast and terrain. By Monday, the vast
majority of ensemble members indicate the ridge axis shifts east
of WA and OR, allowing temperatures to begin lowering again into
the 70s for the interior valleys with dry weather continuing.

Ensembles indicate a thermal trough will develop along the
coast at the surface under the high pressure aloft Friday
through this weekend. This pattern is expected to cause winds
to shift from the onshore (westerly) pattern the area has
generally been observing over the past couple of weeks to
offshore (easterly to northerly). At this time, pressure
gradients don`t look to be very high, so winds aren`t expected
to be strong. Instead, expect to see a typical diurnal behavior
of winds becoming easterly on the west side of terrain in the
overnight to morning hours and increasing to peak gusts up to
20-25 mph. Then, winds decrease over the terrain during the day
and increase through the valley from the north in the afternoon
hours, also peak gusts up to 20 mph. The probability of wind
gusts peaking above 30 mph is less than 10% everywhere except
for through the western Columbia River Gorge and surrounding
terrain at 50-65%, which is generally the windiest location
during offshore flow. -03

&&

.AVIATION...Through 06Z Thursday...A mix of flight conditions
across the area as a cold front continues to move inland.
Conditions along the coast are trending towards VFR with low
clouds gradually breaking up and lifting, mainly around KAST as
the front has already dropped south of the site. There is a decent
amount of uncertainty in conditions along the coast overnight
with guidance suggesting persistent low clouds but observations
and satellite imagery depict improving conditions. Given current
conditions, leaning towards a VFR trend with a 20-30% chance for
MVFR/IFR CIGs around KAST through 18z with VFR conditions favored
after 18z. KONP likely stays socked in with MVFR CIGs through the
morning, eventually breaking out late in the morning or early
Wednesday afternoon. Inland terminals remain mostly VFR but
guidance suggests a low cloud deck developing between 08-12z and
persisting through 16-18z. Light winds overnight increase to
around 5-10 kt from the north/northwest after 18z for all
terminals.

KPDX AND APPROACHES...VFR conditions with increasing chances for
MVFR CIGs after 08z up to 60-80% through 14-16z. Conditions clear
out by mid morning with northerly winds around 5 kt after 18z. -19

&&

.MARINE...This afternoon a frontal boundary is slowly dropping
south across the waters with southerly wind gusts in the 20-30
knot range peaking north of Cape Falcon, especially right along
the coastline. A Small Craft Advisory remains in effect for
coastal waters north of Cape Foulweather, including the Columbia
River Bar, into the late afternoon and early evening hours.
Behind the front, winds are expected to abruptly shift to the
northwest, transitioning to a somewhat lighter northerly wind
pattern Wednesday. Another weak system may approach the northern
waters from the west on Thursday, but it likely holds north as
it moves toward the Washington coast then out of the region to
the east. Northerly winds then return Friday, likely persisting
over the weekend.

A mid-period west-northwesterly swell of 6 to 8 ft at 11-12
seconds continues to move through the coastal waters through
tonight, increasing significant wave heights into the 8 to 10 ft
range. Seas then gradually subside to around 4 to 6 ft later in
the week with no other prominent swells of note at this time.
-99/DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210.

&&

$$

www.weather.gov/portland

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