282
FXUS66 KPQR 251029
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
329 AM PDT Sun Oct 25 2026

.SYNOPSIS...A wetter and more active pattern is expected as a
broad low moves into the region for the start of the week. A
brief reprieve is expected on Tuesday, but by the middle of the
week an active pattern is expected to return as multiple
systems bring repeated rain chances with continued near-normal
temperatures.

&&

.DISCUSSION...Today through Saturday...A broad area of low
pressure will slowly push eastward across the Pac NW for the
start of the week. Rain and cooler temperatures are expected as
a cold frontal boundary will spread southward along the coast
early this morning, then push inland into the Willamette Valley
by late this morning. Behind the initial rain band, scattered
to numerous post-frontal showers this evening will linger into
early Tuesday morning before trending drier. The break from
rain showers may be brief as another shortwave tracks overhead
late Tuesday, followed by yet another upper low from Wednesday
through the remainder of the workweek. While rain is unlikely to
persist through this entire period, these systems will bring
repeated chances for rain at the end of what has been an unusually
dry October in the Pacific Northwest. Ensemble mean 48-hour
rainfall totals from 5 AM today through 5 AM Tuesday are 0.50-1.10
inches, with the reasonable high-end amounts of 1.50-2.25 inches
also likely insufficient to support any flooding concerns.

Temperatures through the period will remain near seasonal
norms, namely afternoon highs in the low 50s to low 60s and
overnight lows in the mid 30s to mid 40s. Increased cloud cover
will help limit the threat of freeze or frost conditions until
late next week when there is a chance of clearer overnight
skies allowing for colder temperatures.

Now, what people might want to know about is: Will this system
bring any chance of snow to the Cascades? Well, snow levels are
expected to fall towards 5000 ft as 850mb temperatures look to
drop towards 1C to -1C through the start of this week. This
will allow for light accumulations in the Cascades above pass
level through Wednesday, with accumulations to lower elevations
possible later in the week as 850 mb temperatures look to reach
0C to -2C by Friday. So, don`t be surprised if to look towards
the peaks of Mount Hood, Mount Saint Helens and The Three Sisters
and see some snow. With that in mind, now is the perfect time
to check on any winter weather equipment and emergency supplies
for your household and vehicles. /42-36

&&

.AVIATION...Through 12Z Monday...Generally VFR conditions with
high clouds throughout the airspace. However, these conditions are
expected to only last through around 13Z-15Z Sunday as radar and
ground observations show a cold front slowly pushing inland this
morning. This frontal system has already brought MVFR conditions
along with rain to KAST and these conditions are expected to
slowly develop for all other TAF locations. KONP should see
these conditions by 11Z-13Z Sun, with inland terminals seeing them
by 14Z-16Z Sun (from north to south). Through the TAF period,
probabilistic guidance is suggesting a mixture of high-end
VFR/low-end MVFR with a 10-20% chance of IFR conditions at any
given time through the TAF period across the airspace.

Expect southerly winds to develop before the frontal passage and
persist through the TAF period. Gusts up to 25 kt are expected
along the coast with gusts up to 20 kt for inland locations
through 00Z Monday. Could see some LLWS near KPDX from 17Z-19Z
Sunday as the frontal passage is expected around that time.

Chances of MVFR conditions decrease toward the end of the TAF
period for inland locations with predominately VFR conditions
expected after 03Z Monday. Coastal locations will likely maintain
predominately MVFR conditions after 03Z Monday and through the
remainder of the TAF period.

KPDX AND APPROACHES...Expect VFR conditions with high clouds until
around 15Z Sunday as a frontal system is expected to start to
impact the terminal around that time. As the frontal system
arrives, expect rain and a 30-60% chance of intermittent MVFR
conditions and 10-15% chance of IFR conditions at any given hour
from 15Z Sunday through 03Z Monday. South/southeast winds will
persist through the TAF period around 5-10 kt. Chances of MVFR
conditions decrease toward the end of the TAF period with
predominately VFR conditions expected after 03Z Monday.

Could see some LLWS near KPDX from 17Z-19Z Sunday as the frontal
passage is expected around that time. /42

&&

.MARINE...A slow-moving and steadily weakening area of low
pressure will traverse waters through today. Expect southerly
winds across all waters with gusts approaching 30 kt and seas
building towards 9-12 ft. Current buoy observations at 46089 as
of 0100 AM show seas around 10 ft with southerly gusts around
20-25 kt. Am expecting similar conditions to slowly spread across
all waters, to include the Columbia River Bar through early this
morning. Therefore am maintaining the current suite of Small
Craft Advisories, with staggered onset times as hazardous
conditions spread from northwest to southeast.

Small Craft conditions are expected to persist across all waters
through at least very early Monday morning, with winds and seas
most likely starting to subside by Monday morning for our northern
water zones. These sub Small Craft conditions are expected to spread
from the northwest to southeast as well. Current guidance is
showing a brief period of relatively calmer conditions through
Tuesday. However, there is a 30% chance that another system
approaching the waters mid-week that could yield in another round
of Small Craft Advisory conditions. /42-36

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Monday for PZZ210-251-271.

     Small Craft Advisory until 11 AM PDT Monday for PZZ252-272.

     Small Craft Advisory from 8 AM this morning to 5 PM PDT Monday
     for PZZ253-273.

&&

$$

www.weather.gov/portland

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