365
FXUS66 KPQR 060356 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
855 PM PDT Sun Oct 5 2025

Updated Aviation Discussion...

.SYNOPSIS...Conditions will remain dry and breezy with clear skies
and warm afternoon temperatures through Tuesday as offshore flow
continues. Frost is likely in the Upper Hood River Valley from Odell
to Parkdale between 1-9 AM PDT Monday where winds are much lighter.
Temperatures trend cooler Wednesday onward. Uncertainty remains
regarding when rain showers will return to the area, however most
guidance holds off on precipitation until Friday night or Saturday.

&&

.SHORT TERM...Now through Tuesday night...The short term forecast is
highlighted by dry and breezy conditions with warm afternoon
temperatures and clear skies. This pattern is in response to
strengthening offshore flow in response to a thermal trough building
northward over northwest Oregon while high pressure remains in place
over the Columbia Basin. The NBM continues to suggest widespread high
temperatures in the 70s each day through Tuesday, including coastal
locations where easterly winds should be strong enough to overcome
any sea breeze circulations that will try to develop with daytime
heating. In fact, highs in the mid 70s are likely from Tillamook
southward Monday afternoon, similar to the Willamette Valley and
Portland/Vancouver metro.

East to northeast winds may gust up to 30-40 mph at times Sunday
afternoon through Tuesday morning on exposed ridgetops in the
Cascades and in the western Columbia River Gorge. Gusts up to 25
mph expected in the Willamette Valley and Cascade foothills. While
wind speeds of this magnitude are not strong enough for significant
impacts, it is worth securing any loose outdoor objects you may have.
Note winds will be relatively light in the sheltered Upper Hood River
Valley compared to the rest of northwest Oregon. Although atmospheric
conditions will be drying out with the offshore flow regime in place,
causing daytime relative humidity values to fall quite significantly,
the recent rains will limit any fire weather concerns. Still, those
burning should use caution today through Tuesday morning given the
breezy winds in place.

Lastly, a Frost Advisory has been issued for the Upper Hood River
Valley from 1-9 AM PDT Monday, which includes Odell and Parkdale.
Observed low temperatures across this zone Sunday morning ranged
between 34 and 40 degrees, with the coldest temperatures mainly
limited to the Parkdale area. With clear skies and calm winds in
place again tonight, and the NBM suggesting temperatures will be a
degree or two colder with temperatures cold enough for frost across
most of the Upper Hood River Valley (not solely the Parkdale area),
confidence is high enough for the Frost Advisory. Expect lows between
34-36 degrees from Odell to Parkdale (50-70% chance). Cannot
completely rule out lows as cold as 32 degrees (5-15% chance). Those
residing in this area should consider taking steps now to protect
tender outdoor plants from the cold. Consider temporarily moving
outdoor potted plants indoors if they are sensitive to cold
temperatures. -59


.LONG TERM...Wednesday through Saturday night...The long term
forecast remains uncertain on Thursday and Friday. However,
confidence has increased on Wednesday as models and their ensembles
are now in good agreement. Confidence is high temperatures will cool
on Wednesday, with highs most likely topping out in the 60s across
the lowlands along with a mix of sun and clouds. Winds will lighter
on Wednesday with the continuation of dry weather.

The forecast is particularly uncertain on Thursday and Friday as
ensemble guidance varies more on the synoptic scale pattern. WPC`s
cluster analysis is still showing roughly 50% of the total ensemble
space from the GEFS/GEPS/ENS favoring a closed upper level low
developing over the northeast Pacific, far enough to the west to
bring the return of offshore flow with dry weather and mild
temperatures across northwest OR and southwest WA. The remaining 50%
show the closed low developing near the coast, which would result in
the return of rain showers and cooler temperatures.

Confidence increases for rain Friday night into Saturday, as this is
when ensembles show better agreement for upper level troughing
inland. NBM PoPs and temperatures reflect this well, as 6-hourly PoPs
increase to 70-80% for all locations west of the Cascade crest on
Saturday with daytime highs in the lower 60s. There is currently a
40-60% chance for 0.25" of rain or more with the weather system on
Saturday. -59

&&

.AVIATION...Clear skies and VFR conditions throughout the
airspace prevail through the TAF period as high pressure builds
into the region. Winds will vary from northerly to easterly for
each terminal. For coastal terminals, expect mostly northeasterly
winds under 10 kt through the TAF period, with winds possibly up
to 12 kt between 18-23Z Monday. As for inland along the Columbia
River, northerly winds will be prominent until 15-16Z Monday,
then shift more easterly thereafter (KTTD will be the exception,
with easterly winds through the entire period). All other
terminals (central and southern Willamette Valley) will remain
northerly through the TAF period. Inland winds will remain under
10 kt through most of the TAF period, with winds around 8-12 kt
and gusts up to 20-25 kt possible between 18-23Z Monday.

KPDX AND APPROACHES...VFR with clear skies through the TAF period.
Northerly winds under 10 kt through 16-18Z Monday. Easterly winds
around 8-12 kt with gusts up to 20-25 kt possible between 18-23Z
Monday.
~12

&&

.MARINE...High pressure and tightening pressure gradients due to
a thermal trough developing along the coast will shift winds
northeasterly and allow winds to increase this afternoon. Small
Craft Advisories remain in effect across all the waters south of
Cape Falcon for a combination of north-northeasterly wind gusts
up to 25 kt and choppy seas. Winds remain northeasterly Monday,
but will weaken to less than 20 kts Monday morning. Winds will
increase again in the afternoon and evening hours, but gusts over
21 kts will be mainly for locations 40-60 NM west of the coast.
Confidence for widespread gusts over 21 kt across the outer water
zones was not high enough to warrant another Small Craft Advisory
for Monday afternoon/evening. Seas around 5-7 ft at 9-10 sec today
fall to 4-6 ft at 11-12 sec Monday into Tuesday.      -10/03

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Frost Advisory from 1 AM to 9 AM PDT Monday for ORZ121.

WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ252-253.

     Small Craft Advisory until 8 AM PDT Monday for PZZ272-273.
&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
x.com/NWSPortland