093
FXUS66 KPQR 101752 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1052 AM PDT Mon Aug 10 2026

Updated Aviation Discussion...

.SYNOPSIS...Warm and dry conditions continue through the upcoming
week as temperatures moderate towards August normals. Onshore flow
will keep smoke east of the Cascades, while precipitation chances
remain very low through the end of the week. Temperatures may trend
warmer late this week as a ridge of high pressure develops offshore.
Increasing potential for afternoon convection over the central OR
Cascades Friday into the weekend.

&&

.DISCUSSION...Today through Sunday...Fairly typical summer weather
will continue early this week as near average temperatures are
expected today and Tuesday. This is in part due to zonal flow aloft
and onshore flow in the lower levels. Relatively shallow marine
stratus at the coast will retreat, giving way to mostly sunny skies
this afternoon, while a brief period of clouds will be possible this
morning up the lower Columbia River Valley into the Portland metro
area. Otherwise, mostly sunny skies will allow afternoon
temperatures to warm into the lower to mid-80s for interior
lowlands, and into the mid-60s to low 70s at the coast. Expect
similar conditions on Tuesday.

By Wednesday, there is increasing confidence for upper level
troughing dropping out of British Columbia into Washington and
Oregon. Model forecast soundings are showing a deepening of the
marine layer which would allow for deeper stratus to push into SW
Washington and the northern Willamette Valley, as well as the
potential for squeezing out some drizzle at the coast. This would
also allow for afternoon temperatures to drop a few degrees,
depending on how long morning clouds linger.

Still some uncertainty late in the week in daytime high temperatures
as model spread remains relatively large Thursday and Friday. If
troughing were to linger around, cooler (or near average)
temperatures would be more likely, but a warming trend is also
possible with highs returning into the mid to upper 80s, with at
least a 25% chance of reaching 90 degrees on Friday. Cluster
analysis of the ensembles indicates the potential for upper level
ridging to build offshore with varying degrees of troughing or upper
level low pressure developing near central California. This feature
is also bringing the potential for more convective weather
developing near the central OR Cascade crest both Friday and
Saturday afternoons with the northward push of some monsoonal
moisture. Temperatures are likely to persist near to slightly above
normal into next weekend, with warm and dry conditions likely. /DH

&&

.AVIATION...Through 18Z Tue...Westerly flow aloft continues as we
remain in a zonal pattern through the TAF period. As of 17Z Mon,
marine stratus remains pushed into the coast at an angle,
resulting in stratus over KTMK and KAST, including up the lower
Columbia River into the Portland Metro. The marine stratus has
begun to burn off, resulting in low-end MVFR CIGs scouring out to
VFR at KTMK and terminals around the Portland Metro as of 18Z Mon.
Expect KKLS and KAST to improve back to VFR by 19-21Z Mon
(earliest to latest from KKLS to KAST).

Looking ahead, Willamette Valley terminals will stay VFR through
the TAF period, with the exception of a possible marine stratus
push bringing a 20-30% chance of MVFR CIGs between 12-18Z Tue.
Additionally, there is a 35-45% chance of MVFR CIGs at KKLS
beginning around 11Z Tue. As for coastal terminals, another marine
stratus push will bring a mix of MVFR/IFR/LIFR conditions between
03-18Z Tue. Guidance suggests majority of this time range to
consist of a 70-90% chance of MVFR, 40-60% chance of IFR, and
20-40% chance of LIFR conditions (highest chances at KAST).
Otherwise, north to northwesterly winds increase to 10-15 kt this
afternoon and evening with gusts up to 25 kt along the coast and
up to 20 kt inland.

KPDX AND APPROACHES...VFR conditions with clear skies through the
TAF period. However, there is a 20-30% chance of MVFR CIGs between
12-18Z Tue. Northwest winds 4-6 kt increase to around 10-12 kt
with gusts up to 20 kt by 00Z Tue and weaken by 06-08Z Tue.
~12

&&

.MARINE...High pressure offshore will maintain northerly winds
through much of next week. Surface pressure gradients tighten
again this afternoon with gusts up to 25 kt possible south of Cape
Foulweather through this evening. Will maintain the Small Craft
Advisory in effect today. Winds look to ease slightly on Tuesday
with much lower chances (30%) of wind gusts exceeding 21 kt.
Similar conditions persist through late in the week. Wind driven
seas are expected to remain around 3 to 6 ft through the week. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ253.

     Small Craft Advisory from 3 PM this afternoon to 11 PM PDT this
     evening for PZZ273.
&&

$$

www.weather.gov/portland

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