383
FXUS66 KPQR 152236
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
336 PM PDT Wed Jul 15 2026

Updated marine discussion.

.UPDATE...Thunderstorms along the Cascades appear to be over
performing in the way of lightning and potential hail. CAPE
values are higher than what we normally see for this region, and
we cannot rule out quarter inch to half in hail in some
locations near the Cascade Crest and the higher elevations of
the Cascade foothills. Continuing to watch radar this afternoon,
but with these storms over performing, there may be more
widespread thunder than previously thought and what the
probabilities may suggest. -27

&&

.SYNOPSIS...Warm temperatures feed into an evening of showers
and thunderstorms. Thunderstorm activity will be highest this
evening over the Cascades and Cascade foothills, then will
progress westward impacting the north coast by early Thursday
morning. Around a 20-30% chance of thunderstorms throughout the
area though this afternoon they have initiated a bit earlier
than previously forecast. Cooler on Thursday, then heating up
and drying out over the weekend into Tuesday.

&&

.SHORT TERM...Now through Friday Night...A tightening low aloft
is the main weather maker today as it spins in the northeast
Pacific off of the Oregon and Washington Coast. This low is
associated with an increased level of instability over the
region. Warm temperatures today as high pressure erodes and
southerly monsoonal moisture moves into the area. Radar and
satellite have detected thunderstorms already this afternoon
over the Cascades of Linn and Lane Counties and those chances
will continue as we move northward. Overall looking at a dynamic
scenario with a mix of lightning and rain. Cannot rule out hail
in some of these storms. There is around a 15-20% chance of
thunderstorms within the Willamette Valley north of Salem, and
around a 20-30% chance along the north Oregon and south
Washington coasts. Timing wise, the Cascades will mainly be
impacted this afternoon and evening while the coast will see
those storms closer to Thursday morning. Most storms will be
elevated.

On Thursday, storm activity will dissipate but showers will
linger through the afternoon. Expecting much cooler temperatures
and higher humidity on Thursday.

On Friday, the low will shift inland over British Columbia which
will allow for warmer air to fill into the region. While highs
are not expected to be exceptionally high, will still be
slightly warmer than Thursday. Overall though, looking at near
normal temperatures. -27

.LONG TERM...Saturday through Wednesday...Ridging over the
central CONUS is expected to rebuild into the PacNW, supporting
a warming trend Saturday and into early next week. The interior
lowlands can expect highs in the mid to upper 80s on Saturday,
building into the low 90s for Sunday and Monday. In this
pattern, marine stratus is likely, especially along the coast
though it could transition down the Columbia River into the
interior lowlands. If cloud cover becomes pervasive, it will
have an impact on high temperatures and minimum humidity. There
is some spread among the NBM in exact high temperatures, ranging
from the mid 80s to upper 90s in the 10th-90th percentiles so
could see adjustments moving forward. Moderate HeatRisk is
currently forecast across the interior lowlands, including the
Cascade foothills, for both of these days. Chances for major
HeatRisk are generally 10-30% for the Portland metro and
Columbia River Gorge. Warm temperatures are expected to continue
into the middle of next week as models continue to anchor the
ridge over the CONUS. -19/27

&&

.AVIATION...Southerly flow aloft will continue as an upper level
low spins offshore. Predominately VFR conditions through Wednesday.
Marine stratus is forecast to return along the coast this evening
and produce MVFR/IFR cigs, as early as 01-03z Thu at KONP and 03-06z
Thu at KAST. A stronger marine push tonight is producing a 25-45%
chance of MVFR cigs at most inland sites, higher at 50-70% at KEUG,
after 10-12z Thu. Any lowered cigs inland should improve to VFR by
18-21z Thu. Winds generally north to northwest and light, increasing
to 8-10 kts after 21-23z Wed. The except is KONP where winds are 11-
13 kts with occasional gusts up to 20 kts. Winds decrease after 03-
06z Thu.

The upper level low will approach the coast tonight through
Thursday, bringing increasing chances for showers or elevated
thunderstorms north of Salem. Initially, thunderstorm chances of 15-
20% will be limited to the Cascades between 20z Wed - 12z Thu.
Then chances spread west to the coast and increase to 15-25% from 12-
21z Thu, with best chances along the Coast Range and Coast between
12-18z. Main impact with any thunderstorms is abundant lightning and
brief erratic and gusty winds. Since probabilities are low at each
terminal, have not added to the TAFs at this time.

Smoke aloft is moving north into NW OR and SW WA from a wildfire in
southern OR north of KMFR. This may at times produce a BKN layer
around 15-25 kft.

KPDX AND APPROACHES...VFR expected to continue through Wednesday
night. Northwest winds 7-10 kt decrease after 06z Thu then shift
southerly by 12-14z Thu. There`s a 20-30% chance of MVFR cigs due to
marine stratus developing between 12-16z Thu. If this does occur,
conditions should improve to VFR by 18-21z Thu. There`s a 15-20%
chance of elevated showers or thunderstorms between 12-18z Wed with
main concern frequent lightning and brief gusty and erratic winds.
-03

&&

.MARINE...Benign conditions with a typical summertime pattern
expected through the week. Northerly winds 10-15 kt expected
with afternoon gusts reaching to around 20 kt each day. Seas
could be choppy at times with heights 4-6 feet but could see
some 7 foot seas at 8-10 seconds. There is a 30-60% chance for
Small Craft Advisory (SCA) criteria winds for all waters
Saturday afternoon into Sunday.

A SCA is in effect Thursday morning from 4 AM to 10 AM for
rough seas within the Columbia River Bar due to a very strong
ebb current leading to seas of 6 to 8 ft. -19/03

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory from 4 AM to 10 AM PDT Thursday for
     PZZ210.
&&

$$

www.weather.gov/portland

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