800
FXUS66 KPQR 031218
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
418 AM PST Tue Nov 3 2026

.SYNOPSIS...Mostly dry conditions expected today, followed by inland
fog and low clouds to start Wednesday. An active and wetter weather
pattern returns later Wednesday through the end of the week and
beyond, although will be mixed with periods of dry weather and
slightly warmer than average temperatures. Weather related impacts
over the next 5-7 days remain fairly limited.

&&

.DISCUSSION...Now Through Monday...A low pressure system off the
northern California coast this morning will push east as the upper
level low moves inland this afternoon. On the northwest periphery of
this system, mid-level clouds with mainly virga is streaming north
across the forecast area into southwest WA. Trace amounts of rain
has been observed early this morning. As the upper low moves inland
over northern CA, and inverted upper trough will shift across NW
Oregon, dragging the mid level clouds east of the Cascades by this
evening, with skies clearing tonight. If skies can mostly clear out
before sunset, a few hours of sunshine may allow late afternoon
temperatures to warm into the lower 60s, allowing for a pleasant
early November day. Also of note are the breezy east winds out of
the Columbia River Gorge where offshore pressure gradients are
peaking this morning with gusts to around 20-30 mph across eastern
portions of the Portland Metro area.

A transient upper level ridge then moves east across the region
later tonight into early Wednesday. Clear skies and light winds
should allow for radiational cooling as temperatures fall into the
mid to upper 30s. Chances for fog development also increase into
early Wed morning as the surface inversion deepens. Temperatures
again warm on Wednesday into the upper 50s to near 60 degrees as
southerly winds increase. Mostly dry conditions are likely to
continue through Wed afternoon. But, an upper level shortwave trough
moving across the NE Pacific will quickly push a frontal system
onshore later Wed afternoon at the coast, spreading inland by Wed
evening. Chances for widespread rain peak Wed evening through Wed
night at around 85-100%, though precipitation amounts remain
relatively low. Mean QPF values ranging from around 0.10-0.30 inch
while chances for exceeding 0.50 inch are highest along the coast
(20-40%) and south WA/north OR Cascades and foothills (30-50%). A
few lingering showers will be possible into Friday morning, though
Thursday likely will see an extended dry period with temperatures
warming again a few degrees above normal.

Late Thursday into Friday, cluster analysis of 500 mb heights looks
relatively similar with southwest flow aloft over the NE Pacific and
weak upper level ridging nudging into the PacNW. But, there are
subtle differences that will determine whether areas remain dry or
wet weather returns later this week. Largely this will depend on the
strength of the upper ridge and where the northern jet stream, which
will likely be associated with atmospheric river moisture, will be
directed towards. The latest cluster showing the wetter solution is
dominated by the European ENS while the GEFS is trending more toward
a drier solution for much of the forecast area, keeping much of the
precipitation to the north. So, still quite a bit of uncertainty in
the forecast.

There is actually higher confidence in the forecast over the weekend
as ensembles are in better agreement depicting broad troughing over
the Pacific pushing the upper level ridge farther east over the
Rockies. Temperatures are likely to warm into the 60s across the
area on Saturday before a frontal system spreads rain across the
area late Saturday into Sunday. In fact, there is at least a 50%
chance for 24-hr rainfall amounts in excess of 0.25 inch across the
forecast area.

At this point, 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. However, beyond day 7 into next week (11/10-11/14), almost
all ensemble systems are beginning to show a growing consensus for a
potentially much more impactful and active weather pattern. /DH

&&

.AVIATION...Through 12Z Wednesday...Moist, southerly flow aloft
this morning as an upper level low off the northern CA coast moves
eastward. Mid-level clouds continue to stream northward with very
light rain or virga. Predominately VFR conditions are being
observed, except for some reduced VIS around 4-5 SM at KEUG and
KUAO. Expect these VFR conditions to continue through this evening
as the mid-level clouds scatter out shift east later this
afternoon. Clearing skies and building high pressure late tonight
into Wed morning will bring increasing chances for fog development
after 09z Wed, especially at KEUG and KHIO. Light winds at most
terminals except for breezy east winds at KTTD with gusts up to 22
kt through this morning.

KPDX AND APPROACHES...VFR conditions under a mid-level cloud deck
scattering out later this afternoon. Increasing chances for fog or
low stratus (20-30%) by 10-12z Wed. Light and variable winds
around 5 kt or less expected. /DH

&&

.MARINE...Light offshore winds this morning become more variable
as high pressure settles over the area. A WNW swell continues to
maintain seas at around 9 to 10 ft at 15 to 17 seconds at buoy 29
and 50, while seas at buoy 89 have recently built to 11 to 12 ft.
Guidance suggests this sea conditions will likely persist through
this afternoon so have extended the Small Craft Advisory for the
outer coastal waters beyond 10 NM through 4 PM.

Southerly winds are expected to increase on Wednesday ahead of an
approaching frontal system. There is still some uncertainty
regarding the strength of the southerlies, but there is at least a
70% chance for wind gusts exceeding 21 kt north of Cape Falcon by
Wed afternoon. Winds shift westerly behind the frontal passage
Wed night before southerly winds return later Thursday.

Active weather continues as a series of potentially stronger
frontal systems move through the waters later Thursday into
Friday, and again over the weekend. With these systems come
increased chances for gale force wind gusts exceeding 33 kt from
around 30-70%, highest on Saturday. Incoming westerly swells are
also expected to build seas into at least the mid-teens on Friday
with around a 10-20% chance for significant wave heights exceeding
20 ft. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 4 PM PST this afternoon for
     PZZ271>273.
&&

$$

www.weather.gov/portland

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