FXUS66 KPQR 290412 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
912 PM PDT Fri Mar 28 2025

Updated aviation and marine discussion, and hazards.


.SYNOPSIS...Active weather will continue through Saturday, with
cool, near normal temperatures and persistent showers. Saturday
night into Sunday a brief break in the precipitation as well as
a slight warming trend is expected as a shortwave ridge quickly
moves across the forecast area. However, this will be short
lived as a broad area of low pressure will bring a return of
rain and light Cascade snow by late Sunday night/Monday which
will persist through the middle of the upcoming week.

&&

.SHORT TERM...Today through Sunday Night...Continued troughing
impacting the area, with persistent showers and near seasonable
daytime temperatures through Saturday. Stratiform precipitation
accumulation was somewhat robust throughout last night over areas of
geographic enhancement (Coast Range, Willapa Hills, Cascades), with
several stations reporting total accumulation between 2-3 inches over
the course of Wednesday night. Rain is currently transitioning to
post-frontal showery rainfall, with weaker accumulations expected for
the next 24 hours. Only around a 5-10% chance of 24 hr rainfall
between 5pm Fri to 5pm Sat exceeding 0.25" in the Willamette Valley
and SW Washington lowlands, closer to 50-80% in the Coast Range and
immediate coast. Winds currently are fairly breezy from the south
throughout the region, with peak gusts around 30-35 kts. Winds
gradually weaken beginning this afternoon and into the evening, with
weak south-southwesterly flow around 5-10 kts by the end of Friday
night.

CAPE values remain around 150-250 J/kg this afternoon, and the
possibility of thunderstorms remains around 10-20% this afternoon,
though severe impacts such as hail or destructive winds are not
expected due to a poor convective environment. That said, weak
thunderstorms will be possible throughout Friday afternoon and
evening throughout the area.

Heading into Saturday night, shortwave ridging pushes into the area,
bringing brief drier and slightly warmer temperatures. Daytime highs
on Sunday have a 40-70% chance of exceeding 60 degrees on Sunday,
particularly in the northern Willamette Valley/Portland metro area.
At the coast, a high around the mid-50s is expected Sunday. Ridging
will be fairly short lived as the next system begins pushing in
Sunday night/Monday morning. 							-JLiu

.LONG TERM...Monday through Thursday...Broad troughing returns to the
area late Sunday night/early Monday morning, bringing cooler
temperatures and showery weather again. WPC 500 mb cluster analysis
continues to show near universal agreement in troughing persisting
throughout the majority of the coming week. Overall, no particularly
impactful rainfall is expected at this time. Early ensemble guidance
shows snow levels around 2000-3500 ft, and mountain snow can be
expected at times throughout next week. Currently evaluating
potential for Winter Weather Advisory-level snow in the mountains
with the initial front, particularly in the Lane County Cascades.
Continuing to monitor model output regarding this as we get closer to
this pattern change.									-42/JLiu


&&

.AVIATION...Post frontal showers persist with periods of gusty
winds and even small hail. Showers will continue to dissipate
through the night into Saturday morning. Generally VFR with
periods of MVFR CIGs during heaviest rainfall. CIGs will drop to
around 1000 AGL over the Coast Range, Cascades and areas around
KKLS early this morning. There is around a 40% chance of MVFR CIGs
within the Willamette Valley with around a 50-70% chance from KPDX
northward. Due to cloud breaks this evening, more cooling is
possible. If cooling occurs enough, saturation will cause CIGs to
lower. Confidence is low though as conditions may be mixing just
enough to keep conditions more favorable. The coast will be a
mixture of MVFR and VFR. The other component of the forecast is
winds. Winds have been gusty through the day today with speeds
exceeding 35 kt. A steady decline is occurring and winds will
slowly shift westerly through Saturday. The timing will vary based
on local terrain but generally around the 19-23Z Saturday time
frame.

PDX AND APPROACHES...Rain showers in the vicinity. In heavier
showers, small isolated areas of pea sized hail possible, though
those chances will end around 08Z Saturday. Generally VFR, but
around a 50% chance of MVFR CIGs. Due to mixing with the showers,
trending towards more of a VFR scenario. However, if enough
clearing occurs and the lower atmosphere stabilizes, cannot rule
out lower end stratus. 								-Muessle


&&

.MARINE...Low pressure continues to shift inland tonight with
residual showers. The impacts of the front are beginning to
subside as winds slowly ease, and seas lower. Starting to see
periods increase and wave heights decreasing this evening which
will continue over the next several hours. Still sitting in the
low end hazardous seas range, but will quickly see small craft
advisory level seas/winds become dominate early Saturday morning.
Have issued a Small Craft Advisory starting Saturday morning.
Otherwise, conditions will continue to settle through the weekend.
The next instance of more amplified conditions occurs on Monday
when another frontal system arrives. Will see an increased
southerly wind wave which will become the more dominate feature
for seas. -Muessle

&&

.BEACH HAZARDS...Beachgoers and those participating in the
upcoming razor clam digs should be aware of a moderate risk of
sneaker waves through Saturday afternoon. Be sure to never turn
your back to the ocean and keep a close eye on incoming waves, as
sneaker waves can catch beachgoers by surprise, sometimes
resulting in injury or death. Avoid jetties, large logs, and large
rocks.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Hazardous Seas Warning until 3 AM PDT Saturday for PZZ210-
     251>253-271>273.
     Small Craft Advisory from 3 AM to 8 AM PDT Saturday for PZZ210.
     Small Craft Advisory from 3 AM to 11 AM PDT Saturday for
     PZZ251>253-271>273.
&&

$$

www.weather.gov/portland

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