304
FXUS66 KPQR 161110
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
400 AM PDT Sat Aug 16 2025

.SYNOPSIS...Rain ends from west to east early this morning in the
wake of a cold front progressing eastward over the Cascades. Mainly
dry with mild temperatures the rest of the weekend, aside from a few
stray showers. Onshore flow will maintain seasonable temperatures
early to mid next week with dry weather. Trending warmer and drier
Thursday into Friday as upper level ridging develops over the area.

&&

.DISCUSSION...Saturday through Friday night...Radar, satellite and
surface weather observations from early Saturday morning depicted a
relatively narrow band of stratiform rain extending along a
southwest-northeast oriented cold front from the Washington Cascades
down to Eugene and Roseburg. This band of rain will clear the area
from west to east this morning as the front progresses eastward over
the Cascades. Cloud cover and isolated shallow showers will persist
behind the front today, but most of the day should be dry with mild
temperatures. Note rain totals thus far have generally
underperformed, except at the coast and in southwest WA where most
locations have observed anywhere from 0.5 to 1.5 inches of rain over
the past 24 hours (highest amounts at the coast). Most locations in
the Willamette Valley and Portland metro have observed anywhere from
0.1 to 0.3 inches, except only a few hundredths in Eugene. It appears
the main reason for this is because the front stalled yesterday along
the coast and took longer than expected to reach inland areas. Once
the front finally reached the Willamette Valley, it sped up a bit and
reduced the total duration of rain for these areas.

The forecast from Sunday through Wednesday is highlighted by
persistent southwest flow aloft with low-level onshore flow. This
pattern will maintain near average to slightly below average
temperatures for this time of year with morning cloud cover likely
each day through at least Monday. Dry weather is also expected each
day, however a few stray showers are possible Sunday.

Conditions trend warmer Thursday into Friday in response to upper
level ridging and low-level flow attempting to turn offshore. Overall
model spread for temperatures is minimal on Thursday, suggesting high
confidence for high temps in the mid to upper 80s. Model spread
increases on Friday, with the NBM 10th-90th percentile for high temps
ranging from the lower 80s to mid 90s. The most likely outcome at
this time is for highs in the upper 80s to lower 90s by Friday.
HeatRisk generally remains in the Minor category, but could increase
to the Moderate category if forecast temps increase. -TK

&&

.AVIATION...At 1030z Saturday, a narrow band of light stratiform
rain extended along a southwest-northeast oriented cold front from
the south Washington Cascades to KEUG. Rain was beginning to end
from west to east and should end at all terminals by 12-13z
Saturday as the front progresses eastward. Behind this front,
expect isolated rain showers through 12z Sunday, especially at the
coast. Otherwise expect a mixed bag of flight conditions this
morning. Cigs will mainly be in the MVFR to low-end VFR range
through this morning. Cigs should generally lift to VFR at all
terminals Saturday afternoon, aside from KONP where there is a
30% chance cigs stay below 2000 ft through the day.

PDX AND APPROACHES...Light rain will come to an end by 12-13z
Saturday, bringing improving surface visibilities. Cigs should
generally stay VFR today, however there is a 20-30% chance for
cigs below 3000 ft at any time between 12-18z Saturday. A few
stray showers are possible this afternoon. -TK

&&

.MARINE...Winds have decreased this morning in the wake of a cold
front that finished pushing inland early Saturday morning. Buoy
observations from 3 AM Saturday showed seas hovering around 6 to 7
ft at 8 seconds, primarily driven by a fresh westerly swell.
Expect very little change to the overall sea state through the
weekend as a westerly swell continues around 7 ft, albeit with
wave periods likely increasing to around 10 seconds. This will
result in seas becoming slightly less steep. Winds will remain
weak through the weekend.

High pressure will gradually build over the waters next week,
with winds shifting from southerly on Monday and Tuesday to
northerly Tuesday night into Wednesday. Seas will also lower to 4
to 5 ft. -TK

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
     PZZ251>253-271>273.
&&

$$

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