Damaging Wind and High Wind in Oregon, November 5 to 6, 2025

Area Forecast Discussion
National Weather Service Portland OR
545 AM PST Wed Nov 5 2025

.SYNOPSIS...Strong low pressure over the Gulf of Alaska will
send impactful fronts toward the region through Thursday.
Expect widespread rain and gusty winds with each frontal
passage. There is around a 20-35% chance of thunderstorms on
Wednesday, highest at the coast. A few thunderstorms may be
marginally severe with the main threat being strong winds and
possibly waterspouts or weak tornados. In addition, minor tidal
overflow flooding is expected along portions of Highway 101 and
Fraser Road in Tillamook County around high tide on Wednesday
and Thursday from 10 AM to 3 PM PST. Conditions likely trend
drier late Friday into Saturday.

&&

.SHORT TERM...Now through Wednesday night...Light rain continues across the region as a strong low pressure
system supported by an upper level trough impacts the PacNW.
The trough is expected to become negatively tilted, turning the mid-
level flow more southwesterly. A cold front associated with the
aforementioned low will move through the region later this
morning. Snow level are only expected to fall to around
5000-6000 ft, so not anticipating any snow at pass levels.
However, a good bout of rain is expected with this system. IVT
values along the coast are expected to peak around 750 kg/m/s
and remain above 500 kg/m/s for close to 24 hours leading to a
moderate AR. IVT values inland around the foothills will be
lower, peaking short of 500 kg/m/s but staying above 250 kg/m/s
for 24-30 hours. Expect another 1.0-1.5 inches of rain along
the coast and Coast range through tonight, another 0.5- 1.0
across the interior lowlands, and 1.5-2.5 inches along the
Cascades and Cascade Foothills with locally higher amounts on
the peaks.

The offshore pressure gradient between The Dalles and Troutdale will
continue to support easterly wind gusts around 30-40 mph through
Wednesday morning. Winds turn to the south areawide as the cold
front passes through the area. Gusty winds will continue with
this system as winds turn to the southwest. There is a 15-30%
chance for wind gusts to reach 45 mph (Wind Advisory criteria)
from Salem southward in the Willamette Valley and a 10-20%
chance wind gusts along the coast reach 58 mph (High Wind
Warning criteria, no advisories for coastal areas). Most likely
will see wind gusts around 30-40 mph inland and 45-50 mph at the
coast, with gusts up to 55 mph along beaches and headlands.
This would be strong enough to result in some tree damage and
power outages, but would not be strong enough for widespread
downed trees and significant impacts.

With the cold front passing through the region this morning and
the upper level trough tilting negatively, an unstable
atmosphere will be in place come the afternoon and evening hours
leading to a 15-30% chance for thunderstorms. The environment
will be supportive of low- topped convection with the highest
probabilities along the coast through the threat extends
areawide. Guidance suggests "skinny" surface based CAPE peaking
around 250-500 J/kg in the afternoon and strong wind shear as
850 mb southwesterly winds persist at around 50 kt and 0-3 km
SRH increases to around 150-250 m2/s2. SPC has maintained the
marginal threat for severe thunderstorms wast of the Cascades
for northwest Oregon and southwest Washington. Given the decent
SRH, storms may rotate and support weak waterspouts or tornados
if they come onshore with a 2-4% probability mainly along the
coast and extending into the western Willamette Valley. The
threat for wind is is 5-14% for areas west of the Cascade crest
with a similar threat for 1 inch or greater hail. /19

.LONG TERM...Thursday through Monday...The next system is expected
to move into the region on Thursday, bringing another round of
rain and gusty winds. Wind speeds with this front look to be
fairly similar to Wednesday, though probabilities for stronger
wind gusts have increased slightly, but a shorter duration of
these stronger winds is expected as the front moves through.
This frontal system is also on track to produce lower rainfall
amounts. WPC QPF amounts from 4am Thursday through 4am Friday
range between 0.75-1.0 inches for inland valleys, 1.0-2.0 inches
for the coast and Cascade foothills, and 2-3 inches for the
Coast Range and south WA/north OR Cascades. Given all the rain
that is forecast to fall prior to the system on Thursday, rising
river levels will be a concern. The main question that remains
is whether or not enough rain will fall for some rivers to reach
flood stage on Wednesday and/or Thursday. According to the
latest HEFS guidance, the probability for any given river to
reach minor flood stage is generally 10% or less, except a 15%
chance for the Wilson River near Tillamook. Another river of
concern would be the Grays River near Rosburg. Small creeks and
streams are more likely to see some minor flooding. Lastly,
minor urban flooding will also be possible, especially in low-
lying areas with poor drainage.

Rain chances remain in the forecast Friday, however ensemble
guidance suggests rain amounts will be lighter and less impactful.
WPC 500 mb cluster analysis shows good agreement for an upper level
ridge axis too be positioned along the west coast and into the PacNW
which would support dry conditions. Cluster and ensemble
analysis have trended drier Sunday into early next week.
Clusters depict the ridge remaining most the most influential
feature over the region into Tuesday. Expecting NBM trends to
catch up with this drier solution. Ensembles from the Euro and
GFS only show about 1/3 of members bringing light precipitation
to the region Monday and Tuesday. Will continued monitor this
trend. /19

&&

.AVIATION...VFR conditions across the region with light rain
continuing to stream in along southerly flow. Models suggest
wind speeds between 1000-2000 ft AGL are around 40-50 kt.
Therefore, have included mention of LLWS into some of the
forecasts. Areas where this will be most prevalent will be in
the northern Willamette Valley where surface winds are northerly
and winds aloft will be southwesterly with the front. Expect
light to moderate rain to increase this morning as the cold
front moves through, turning more showery behind the cold front
this afternoon. Winds will increase from the south with the
passage of the front with gusts to 25-35 kt along the coast and
20-30 kt inland. CIGs expected to remain largely VFR but
scattered MVFR CIGs are possible with a 20-60% probability
behind the front, due to the more convective nature of the
precipitation.

Thunderstorms are also possible after 16-18z Wednesday with best
chances for locations west of the Cascades. Thunderstorms could
cause erratic and gusty winds up to 45-50 kts, small hail, heavy
rain, and possibly funnel clouds or waterspouts. Periods of heavy
rain could cause rapid reduction of visibility to IFR/LIFR
conditions. The limiting factor will be whether or not we
experience enough clearing during the day.

KPDX AND APPROACHES...Rain with generally VFR conditions. Gusty
easterly winds with gusts up to 30 kt. Aloft, southwest winds up
to 55 kt possible thus leading to potential for LLWS up to 2000
ft. LLWS may maintain through the forecast period however will
likely rise above 2000 ft thus has been phased out later in the
TAF. Chance for thunderstorms after 20Z Wed. Can't rule out small
hail, gusty outflow winds, building cumulus, and even some funnel
clouds. Will note that there is low confidence in regards to MVFR
CIGs developing due to more persistent easterly winds through the
morning hours.											-19/27

&&

.MARINE...Winds are beginning to build over the waters with
observations showing gusts up to 35 kt at 46089 and 35 to 40 kt
at coastal buoys. These winds will continue to build as the
warm front shifts over the waters. Strong southerly flow with
convergence along the coast will develop a weak coastal jet.
Gale force winds expected with less than a 30% chance of Storm
Force Winds. If storms do form they would likely be in PZZ273.
Seas will gradually increase with wave heights in the teens.

Winds will gradually ease tonight and thus the Gale Warning will
likely end. However, seas will remain elevated all zones will
transition into a Hazardous Seas Warning. The outer waters
transition at 7 pm while the inner waters and Columbia River Bar
hold onto Gale force winds until around 10 pm.

Another system is set to bring another round of Gales to all
waters by Thursday morning. There is a 5% chance of combined
seas of 21 ft or greater. -19/27

&&

.BEACH HAZARDS...There is a Coastal Flood Advisory for minor
tidal overflow flooding during high tide from 10 AM to 3 PM
Wednesday and 10 AM to 3 PM Thursday for the Pacific County
Coast, Clatsop County Coast, and Tillamook County Coast. Minor
flooding during high tide is expected in the low lying areas
near bays, sloughs, and the lower reaches of the coastal rivers.
This is due to total tide up to 12 feet at Toke point resulting
in tide up to one foot above ground level, total tide up to 11
feet at Tongue Point resulting in tide up to one foot above
ground level, and total tide up to 11 feet at Garibaldi
resulting in tide up to one foot above ground level.

Expect flooding along portions of Highway 101, including near
Raymond, Seaside, and Fraser Road in Tillamook County. Coastal
residents in the warned area should be alert for rising water and
take appropriate action to protect life and property. Remain out
of the water to avoid hazardous swimming conditions. Minor
tidal overflow is possible again on Friday as active weather
coincides with the King Tides.

Additionally, there is a High Surf Advisory for large waves and
hazardous surf conditions from 4 AM to 7 PM on Thursday due to a
strong westerly swell. Destructive waves may wash over beaches,
jetties, and other structures unexpectedly. People can be swept
off rocks and jetties and drown while observing high surf. Minor
beach erosion may damage coastal properties and buildings. Higher
than normal water run-up is expected on beaches and low-lying
shoreline. Remain away from the shoreline to avoid these conditions.
-03

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Coastal Flood Advisory from 10 AM this morning to 3 PM PST this
     afternoon for ORZ101-102.

     Coastal Flood Advisory from 10 AM to 3 PM PST Thursday for
     ORZ101-102.

     High Surf Advisory from 4 AM to 7 PM PST Thursday for ORZ101>103.

WA...Coastal Flood Advisory from 10 AM this morning to 3 PM PST this
     afternoon for WAZ201.

     Coastal Flood Advisory from 10 AM to 3 PM PST Thursday for
     WAZ201.

     High Surf Advisory from 4 AM to 7 PM PST Thursday for WAZ201.

PZ...Gale Warning until 10 PM PST this evening for PZZ210-251>253.

     Hazardous Seas Warning from 10 PM this evening to 7 AM PST
     Thursday for PZZ210-251>253.

     Gale Warning until 7 PM PST this evening for PZZ271>273.

     Hazardous Seas Warning from 7 PM this evening to 7 AM PST
     Thursday for PZZ271>273.
&&

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