102
FXUS66 KPQR 041216
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
416 AM PST Wed Nov 4 2026

.SYNOPSIS...Dry weather expected through early this afternoon before
light rain begins to push onto the coast by mid-afternoon, spreading
inland by this evening. An active weather pattern continues through
the remainder of the week and beyond. However, many inland locations
will likely see only light accumulations until a stronger system
arrives later this weekend. Slightly warmer than average
temperatures are expected through Saturday.

&&

.DISCUSSION...Now Through Tuesday...Water vapor satellite imagery
early Wednesday morning shows the PacNW in-between systems as a
transient ridge of high pressure moves over the region. Clearing
skies and radiational cooling this morning has allowed for patchy
dense fog to develop across the southern Willamette Valley. Have
issued a Dense Fog Advisory for the lowlands from Albany to Eugene
through 10AM this morning. There is potential for fog to spread
northward as the mid-level clouds over northern portions of the area
continue to shift east, but confidence is low. If you encounter
dense fog Wednesday morning, remember to keep your vehicle
headlights on and slow down.

Afternoon temperatures warm into the mid 50s to near 60 degrees as
southerly winds increase ahead of our next approaching weather
disturbance in the form of an upper level shortwave trough moving
across the NE Pacific. The associated frontal system is slated to
arrive by mid-afternoon at the coast, spreading rain inland by this
evening.Precipitation amounts remain relatively low, with mean QPF
values ranging from around 0.01-0.10 inch inland, and closer to 0.10-
0.30 inch at the coast and nearby terrain. A few lingering showers
will be possible into Thursday morning, though Thursday will likely
see an extended dry period much of the day with temperatures warming
again a few degrees above normal.

Uncertainty reigns for Friday as to how far south rain, associated
with a weak atmospheric river, will shift. There continues to be
large differences between the GEFS, which wants to keep the moisture
farther north, and the European ENS, which weakens the upper level
ridge allowing for moisture to slide farther south on Friday. The
line between wet and dry across our forecast area will likely wobble
back and forth near the Portland Metro Area (with areas to the south
remaining dry) over the next few days. The spread between the 10th
and 90th percentiles of the NBM remain relatively high.

There remains decent confidence in the forecast over the weekend as
ensembles are in good agreement depicting broad troughing over the
Pacific pushing the upper level ridge farther east over the Rockies.
Temperatures are likely to warm well into the 60s across the area on
Saturday (near record highs) before a frontal system spreads rain
across the Pacific Northwest late Saturday into Sunday. All that
being said, no significant precipitation impacts are expected with
any of these weather systems over the next 5 to 7 days, and snow
levels hold around 5000-6000ft before lifting again this weekend.
Keep in mind storm drains tend to get easily clogged this time of
year. However, beyond day 7 into next week (11/11-11/15), a large
number of ensemble systems are beginning to show a growing consensus
for a potentially more impactful and active weather pattern.  DH/99

&&

.AVIATION...Through 12Z Thursday...Light northwest flow aloft
becoming westerly later this morning as an upper level ridge of
high pressure moves across the region. A few broken mid-level
clouds persist over northern portions of the forecast area, but
where clearing is occurring dense fog has develops, particularly
within the southern Willamette Valley. LIFR conditions likely
persist through 18z at KEUG, while reduced VISBY are likely this
morning at KHIO, KUAO and KSLE to around 2-4SM. Meanwhile, light
easterly winds and the lingering clouds should maintain VFR
conditions at KTTD and KPDX. Calm winds along the coast may also
allow for some mist to form, though increasing offshore flow may
decrease chances for lower flight conditions at KAST and KONP.
As of 11z, satellite imagery is showing some MVFR marine stratus
developing just west of KAST. A front will approach the area later
this afternoon, bringing a brief period of rainfall and lowering
CIGs. At this time, VFR conditions are likely to hold on through
04-06z with MVFR CIGs likely developing behind the front. Breezy
south winds ahead of the front are likely with gusts up to 20 kt.

KPDX AND APPROACHES...Predominately VFR conditions are expected
through 06z Thursday. There is around a 20% chance for surface
visibilities below 3SM between 12-17z Wednesday. Light rain is
expected to begin this evening sometime between 00-01Z Thu ahead
of an incoming front. Chances for ceilings below 3000 ft increase
after 06Z Thu to around 50%. Southeast winds around 4-7 kt are
expected through this evening. /DH

&&

.MARINE...An active pattern arrives as a series of frontal
systems will impact the coastal waters beginning today and
continuing through the weekend. Southerly winds are expected to
increase through this afternoon into early this evening as a
frontal system moves across the waters. Small Craft Advisories are
in place for winds gusting up to 25-30 kt through 10 PM. Winds
shift southwest to westerly behind the front as it pushes onshore
tonight. Winds ease, but a westerly swell will begin moving into
the waters late tonight, building seas to around 9 to 11 ft at 14
seconds by Thursday morning. Therefore, have extended Small Craft
Advisories through Thursday evening.

After a brief lull in winds, southerlies increase again late
Thursday into Friday as another frontal system approaches the
waters. There is around a 50-70% chance for gale force wind gusts
north of Cape Falcon on Friday. Steep and hazardous seas will also
be possible later Friday as significant wave heights likely build
into at least the mid-teens, though currently just a 10% or less
chance for seas reaching 20 ft.

A potentially stronger front is expected to quickly approach the
area late Saturday, bringing more widespread chances for Gales
(40-80%, highest to the north) across the coastal waters. Another
westerly swell will likely build seas into the mid to upper teens,
with around a 15-30% chance of wave heights exceeding 20 ft. The
active weather pattern likely continues into early next week. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Dense Fog Advisory until 10 AM PST this morning for ORZ116>118.

WA...None.
PZ...Small Craft Advisory from 1 PM this afternoon to 10 PM PST this
     evening for PZZ210.

     Small Craft Advisory from 7 AM to 10 PM PST Thursday for PZZ210-
     253-273.

     Small Craft Advisory from 1 PM this afternoon to 10 PM PST
     Thursday for PZZ251-252-272.

     Small Craft Advisory from 1 PM this afternoon to 7 PM PST this
     evening for PZZ253-273.

     Small Craft Advisory from 10 AM this morning to 10 PM PST
     Thursday for PZZ271.
&&

$$

www.weather.gov/portland

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