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288
FXUS66 KPQR 101700 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1000 AM PDT Thu Jul 10 2025

Updated Aviation and Marine Discussions

.SYNOPSIS... Dry with seasonable temperatures for interior
valleys this afternoon. High pressure builds Friday into the
weekend, leading to much warmer temperatures. Increasing
potential for triple digits inland next Tue/Wed.

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.SHORT TERM...
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Now through Friday night...Expect another day with
near normal temps as weak troughing remains in place across the
PacNW. The day will start out party to mostly cloudy, clearing
through the day. Highs in the upper 70s to low 80s expected
inland with low to mid 60s expected along the coast. Friday will
see temps jump 8-12 degrees for most inland locations as high
pressure builds across the northeast Pacific along with
thermally induced low pressure over the Willamette Valley. Highs
in the upper 80s to around 90 degrees expected inland while the
coast warms a few degrees into the mid 60s to low 70s. -Batz


.LONG TERM...Saturday through Tuesday...For the weekend, the heat is
on. WPC 500 mb cluster guidance continues to show very good
agreement as a ridge of high pressure building and strengthening
over the Eastern Pacific and Pac NW through at least early next
week. There are some slight variations in exact strength and
placement of the ridge over the region, but a prolonged period
of upper 80s to low 90s throughout the Willamette Valley look
good. There is also a decent chance (30-70%) for widespread
triple digits throughout the Willamette Vally and interior
lowlands next Tuesday and Wednesday.

Probabilities for highs to reach 95 or greater from Salem to Eugene
on Saturday are 30-50%, on Sunday it is 70-90% and on Monday it is
30-50%. Probabilities around the Portland/Vancouver Metro on
Saturday are 10%, on Sunday 30-50% and Monday to 10-20%. At this
time, HeatRisk is expected to remain moderate through Monday. There
is a slim chance (around 10%) for a few locations in the central and
southern Willamette Valley to reach 100 Sunday and Monday. Chances
for triple digits increase dramatically Tuesday and Wednesday as the
ridge strengthens. Probabilities for highs to reach 100 or greater
for various locations in our Forecast Area on Tuesday and Wednesday
(7/15/2025, 7/16/25):

Portland/Vancouver Metro: 30-60%, 50-80%
Salem: 60-70%, 50-70%
Eugene: 50-70%, ~50%
Battle Ground: 30-40%, 40-50%
Kelso/Longview: 15-30%, 30-40%
Astoria: less than 1% both days
Hood River: 15-30% both days
Newport: less than 1% both days
Oakridge: 5-10% both days

Temps have trended toward the upper 90s to low 100s for Tuesday and
Wednesday, pushing HeatRisk values to Major for portions of the
Willamette Valley and Columbia River Gorge.

In addition to the upper level high pressure, models are also
showing the development of a thermally induced trough slowly
spreading northward into the Willamette Valley towards the start of
next week. If this solution within the models does manifest, then
will likely result in offshore flow. Lastly, expect most of the area
to remain dry through the end of the long term IE no precipitation
in the forecast at this time. However, models are hinting at a
possible pattern change come Wednesday/Thursday and that could bring
some very light precipitation into the forecast, but model
probabilities are too low to warrant inclusion of any precipitation
in the forecast for now, but will continue to monitor as models
start to better resolve this feature in the coming days.
-Batz/42
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&&

.AVIATION...
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Marine stratus across the air space will slowly scour
out resulting in a mixture of VFR/MVFR conditions for inland
locations and a mixture of all flight conditions along the coast,
with most locations along the coast being in VFR or MVFR
conditions. Currently, winds variable under 5 kts, but northerly
winds pick up around 20Z Thursday and continue through 02Z Friday
with gusts up to 20 kts possible at all terminals.

Westerly flow continues across NW Oregon and SW Washington through
the TAF period. As a result, expect similar conditions as to what
has been observed over the past 24-48 hours. Expect coastal
conditions to develop IFR/LIFR conditions around 00Z-03Z Friday
For inland locations, while onshore flow will be present, it will
be northerly and this pattern will mitigate any marine stratus
infiltrating through the gaps and flows as well as the Columbia
River. However, models are showing some backbuilding clouds off
the Cascades and that could bring some MVFR flight conditions to
northerly (KPDX,KTTD,KVUO) and south/central (KSLE and KEUG)
terminals. These conditions will likely start around 10Z-12Z
Friday. Aftewards, across the airspace expect any lowered flight
conditions that developed to slowly improve starting around
12Z-15Z Friday.

PDX AND APPROACHES...Predominately VFR conditions through the
majority of the TAF period. Backbuilding clouds off the Cascades
will likely bring MVFR conditions to the the terminal and eastward
starting around 12Z Friday. Conditions expected to improve back
towards VFR around 16Z-18Z Friday. Winds variable under 5 kts,
but northerly winds pick up around 20Z Thursday and continue
through 02Z Friday with gusts up to 20 kts possible. /42
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&&

.MARINE...
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North/northwest winds across all waters and persist
through the weekend as a broad area of high pressure and a
thermally induced trough spreads northward. As the high pressure
and associated thermally induced trough mature, expect gusty
northerly winds and choppier wind driven seas, particularly south
of Cape Falcon. Winds and seas will be strongest off the central
coast of Oregon and will typically peak in the afternoon and
evening hours over the inner waters each day through the weekend.
/42
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&&

.PQR WATCHES/WARNINGS/ADVISORIES...

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OR...None.
WA...None.
PZ...None.
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&&

$$

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