790
FXUS66 KPQR 182042
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
142 PM PDT Sat Jul 18 2026

.SYNOPSIS...A steady warming trend will continue through the
weekend as high pressure strengthens across the region. Inland
temperatures will rise into the 80s this weekend, then into the
upper 80s to mid 90s early next week. Hot and dry weather is
expected to persist through at least midweek, with increasing
heat impacts possible across the interior lowlands.

&&

.DISCUSSION...Tonight through Friday...A synoptic scale pattern
shift continues through the weekend and into next week. High
pressure over The Great Basin will continue to strengthen
resulting in a warming and drying trend across the CWA through
at least the middle of next week. While high pressure will build
in the mid and upper levels of the atmosphere, onshore
(north/northwest) flow will persist near the surface and provide
some temperature mitigation, or in simpler terms: Onshore flow
will help to keep the region slightly cooler. Even with onshore
flow, inland temperatures will warm day by day, while coastal
areas remain noticeably cooler, but still experience a warming
trend even with the persistent onshore flow.

Sunday, most inland locations are expected to reach the mid 80s
to low 90s. Along the coast, highs will remain relatively cooler,
with daytime highs in the mid 60s to mid 70s. Higher elevations
will will see daytime highs in the upper 70s to upper

Monday through Wednesday, The Great Basin ridge is expected to
peak in strength. This is resulting in high confidence in
Monday`s forecast, with interior lowland highs in the upper 80s
to low 90s. The coast will have highs in the mid 60s to mid 70s,
with higher elevations having highs in the upper 70s to upper
80s. Tuesday and Wednesday, uncertainty grows significantly. The
majority of the uncertainty can be tied to two features within
the eastern Pacific. The first id a low off the California
coast, which could drive some monsoonal moisture into the
region. The second feature is what tropical moisture remains
from Tropical Storm Elida, which is currently centered near
19.45 N/-123.57 W, which places it southwest of the Baja
Peninsula. TS Elida, is forecasted to weaken through the early
part of next week as it continues to push northward into the
central and northeastern Pacific. So, with all that in mind,
even modest increases in cloud cover or moisture could easily
influence afternoon temperatures and is reflected in ensemble
guidance as well as WPC 500 mb clusters, which show a fairly
even spread between the four different clusters through the
middle of next week.

Despite that uncertainty, the overall message remains the same:
Tuesday and Wednesday still appear likely to be the hottest days
of the period for many inland locations. Probabilistic guidance
continues to support a moderate to high chance of 90-degree
temperatures across much of the interior lowlands, with the
higher odds on Tuesday and Wednesday. There is also a meaningful
chance (20-30% chance on Monday, 30-50% chance on Tuesday and
Wednesday) that some of the traditionally warmer valleys push
into the mid 90s. With several consecutive hot afternoons and
only limited overnight cooling, Moderate HeatRisk appears
increasingly likely for portions of the interior lowlands,
especially for those without effective cooling or for anyone
spending extended time outdoors. There is also a lower-end
chance (15-35%) for pockets of Major HeatRisk if temperatures
end up on the warmer side of the forecast envelope.

By Thursday and Friday, guidance still favors a slight easing
of the heat as the two, aforementioned systems, combined
broader upper-level low coming from the Gulf of Alaska, will
help to push The Great Basin high eastward. Even with a pattern
change for the latter part of next week, daytime highs look to
remain a few degrees above normal for late July. /42

&&

.AVIATION...Southwest to westerly flow aloft continues through
the TAF period as an upper low moves through British Columbia.
Predominately VFR conditions across the airspace. Another marine
push is expected tonight into tomorrow morning. MVFR/IFR cigs
expected to form along the coast again, initially near KAST by
04-06z Sun, spreading south to KONP by 08-12z Sun. Additionally,
there`s a 35-45% chance of MVFR ceilings developing between 10-14z
Sun inland stretching from the Portland metro to KSLE, including
KPDX and KTTD. Any lowered flight conditions are expected to
improve to VFR by 18-21z Sun. Expect north to northwest winds to
8-12 kts inland, up to 15 kts along the coast with gusts up to
20-25 kts. Winds decrease less than 8 kts by 06-09z Sun.

KPDX AND APPROACHES...Predominately VFR conditions through the
TAF period. There is a 30-45% chance of MVFR CIGs 12-18z Sun.
Northwest winds around 8-12 kt with occasional gusts up to 20 kt,
decreasing after 04-06z Sun. -03

&&

.MARINE...A typical summertime pattern will continue through
early next week with persistent north to northwest winds over
the coastal waters. Winds will be strongest during the afternoon
and evening hours each day, especially through weekend for the
waters south of Cape Falcon. Expect wind gusts up to 25 kt over
the central and southern waters this weekend, with seas becoming
steep on Sunday due to a fresh northwest swell around 6-7 ft at
7-8 seconds. By Sunday afternoon, these gusty winds and steep
seas will expand into the waters north of Cape Falcon. Between
the increasing winds and steepening seas, conditions will become
hazardous to small craft. As such, Small Craft Advisories are
in effect from Saturday afternoon through late Sunday.

Winds decrease below 20 kts early Monday morning, with seas
becoming less steep through the day Monday as the swell decreases.
Benign conditions expected Tuesday into late next week.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory from 2 PM Sunday to 2 AM PDT Monday for
     PZZ251-271.

     Small Craft Advisory from 5 PM this afternoon to 2 AM PDT Monday
     for PZZ252-272-273.

     Small Craft Advisory until 2 AM PDT Monday for PZZ253.

&&

$$

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