Lake Oswego, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

780
FXUS66 KPQR 130428
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
928 PM PDT Thu Jun 12 2025

Updated aviation discussion.

.SYNOPSIS...Expect mostly dry weather the next few days besides
a 10-15% chance for light drizzle across our coastal areas
Friday morning. Onshore flow should keep temperatures near
normal through the forecast period. Early next week chances for
light rain increase although amounts still appear rather light
overall.

&&

.SHORT TERM...Now through Sunday night...Headed through the end
of work week into the weekend our onshore flow regime which has
sat overhead the last couple of days will continue keeping
temperatures close to normal for this time of year. Tonight into
Friday conditions will trend just a touch cooler with 850 mb
temps decreasing several degrees aloft thanks to a weak passing
shortwave trough aloft. While it won`t produce widespread
precipitation this feature will help deepen the marine layer
compared to past days resulting in a 10-15% chance of light
drizzle at the coast and increasing chances for morning cloud
cover for inland valleys, mainly to the north of Salem. Thus,
confidence is high daytime temperatures only rise into the low
70s across the inland valleys - upper 50s for locations along
the coast.

We`ll trend warmer again on Saturday once this weak shortwave
passes well to the east towards the rockies, heights build
aloft, and morning stratus decreases in coverage. Then Temps
trend a few degrees warmer still on Sunday, which is currently
expected to be the warmest day of the week with the highest
chance for highs of 80 degrees or warmer over inland valleys
(20-50% chance). -Schuldt


.LONG TERM...Monday through Wednesday night...The long term forecast
is highlighted by chances for light rain Monday night through
Wednesday morning in response to an upper level trough. While most
ensemble members from the 00z/June 12th iteration of the
ENS/GEFS/GEPS show at least some measurable rain with this trough
(generally under 0.1-0.2" with the highest amounts at the coast and
the lowest amounts from Salem to Eugene), there are significant
timing differences evident; some members bring rain into the area as
early as Monday, while others hold off until late Tuesday. In
addition, there is a small handful of members showing no rain at all,
mainly from the GEFS/GEPS. Nevertheless, the NBM is showing a 20-40%
chance for 48-hr rain amounts of 0.1" or more from 5am Monday to 5am
Wednesday, except 50-60% across southwest WA and 60-75% along the
coast. As if often the case this time of year, coastal locations and
more northern locations are favored to see the most rain, assuming
rain does occur with this system.  -TK

&&

.AVIATION...Upper level low pressure remains over the PacNW
through the TAF period, continuing north to northwest surface winds
over NW Oregon and SW Washington. Winds expected to become light
around 3-6 kts after 06-08z Fri for all terminals. Winds increase
again after 18-21z Fri with inland winds 7-10 kts with gusts to 18-
20 kts and coastal winds 10-15 kts with gusts 20-25 kts.
Predominately VFR conditions expected through the TAF period except
for KAST where there`s an 80-90% chance of MVFR ceilings through 18-
21z Fri and KPDX and KTTD where there`s a 40-60% chance of MVFR
ceilings from 11-17z Fri.

*KTTD ASOS is currently out of commission except for altimeter and
will be AMD not SKED.

PDX AND APPROACHES...Predominately VFR conditions through the TAF
period except for a 40-60% chance of MVFR ceilings from 11-17z Fri.
North to northwest winds decreasing to 3-6 kts after 08z Fri,
increasing again to 8-11 kts with gusts up to 18 kts after 21z Fri.
-HEC

&&

.MARINE...North/northwesterly flow continues as a a broad, upper
level trough pushes inland through tomorrow. Winds generally
10-15 kt with gusts up to 25 kt through Friday morning. Seas 7 to
9 ft at 8 to 9 seconds. This will result in steep and choppy
conditions at times across all waters. Added the inner waters to
the current Small Craft Advisory and extended all Small Craft
Advisories through at least Friday night as seas are expected to
remain elevated. Will note that conditions are marginal so
conditions may not be met at times. /42

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 11 PM PDT
     Friday for PZZ251>253.
     Small Craft Advisory until 11 PM PDT Friday for PZZ271>273.
&&

$$

www.weather.gov/portland

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