110
FXUS66 KPQR 111745 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1045 AM PDT Fri Jul 11 2025

Updated aviation and marine discussion.


&&

.SYNOPSIS...High pressure builds over the area, supporting
warmer temps in the upper 80s to low 90s today through Sunday.
Expect morning marine clouds along the coast and over the
waters. Temperatures cool slightly on Monday, but still remain
very warm and dry. An Extreme Heat Watch is in place for some
interior valley locations from Tuesday to Wednesday next week as
temperatures between 95 to 105 degrees are possible with
overnight lows struggling to fall below 65 to 70 degrees.

&&

.SHORT TERM...Now through Saturday night...Conditions begin to
heat up today as high pressure builds back into the region.
Afternoon highs in the upper 80s to low 90s expected across
interior valleys while the coast remains mild in the 60s to low
70s with onshore flow. Expect breezy northwesterly winds along
the coast with gusts up to 25 mph, while northerly winds gust up
to 20 mph across the Willamette Valley. The strongest winds
will be in the afternoon when pressure gradients are tightest.
High pressure persists on Saturday, maintaining similar
temperatures with generally northerly flow. -Batz/Alviz

.LONG TERM...Sunday is still expected to be the warmest day of
the weekend with highs jumping into the low to mid 90s
throughout the Willamette Valley, Portland/Vancouver Metro, and
western Columbia River Gorge. This will lead to widespread
Moderate HeatRisk - this level of heat affects most individuals
sensitive to heat, especially those without effective cooling
and/or adequate hydration. Conditions are still below Heat
Advisory criteria but if highs trend warmer in future guidance a
headline may be warranted for the day. Monday sees highs cool
5-10 degrees across much of the area as a shortwave trough
passes overhead in the mid levels.

All eyes are on Tuesday to Wednesday as there is potential for
extreme heat. An Extreme Heat Watch is in place from Tuesday
afternoon (July 15) to late Wednesday evening (July 16) across the
Greater Portland/Vancouver Metro, Western and Central Columbia River
Gorge, the Corbett area and the Hood River Valley, Lower Columbia
River and Cowlitz River Valleys, and Central Willamette Valley.
Dangerously hot conditions with temperatures between 95 to 105
degrees are possible. Low temperatures between 65 to 70 degrees are
expected Tuesday night, which would limit overnight relief.
Currently, this Watch encompasses areas where overnight low
temperatures may struggle to fall below 65 to 70 degrees.

The latest guidance suggests that there is a 40-80% chance that
Tuesday night low temperatures remain above 65 degrees for most
locations outside of the coastal areas. Probabilities for lows
to remain at 70 or above have come down to 20-40% and are mainly
around urban areas and the coast range where locations may
remain in the thermal belt. As a reminder, an Extreme Heat
"Watch" is issued when dangerous heat is possible. An Extreme
Heat "Warning" is issued when dangerous heat is happening or
about to happen.

Major HeatRisk is currently forecast for areas within the Extreme
Heat Watch. This level of heat would affect anyone without effective
cooling and/or adequate hydration. Heat related illnesses increase
significantly during extreme heat events.

In addition to the upper level high pressure, models are also
indicating a thermal trough developing over the Willamette Valley on
Tuesday. If this occurs, then it would lead to more offshore flow.
Currently, the easterly winds forecast with this thermal trough are
not looking very strong, and will mainly be through the Columbia
River Gorge and Cascades. Current guidance shows pressure gradients
of -2 to -4 mb through the Gorge Tuesday and Wednesday, which would
lead to wind gusts up to 20-25 mph in that area. Min RH values both
days may also drop into the 20-30% range which combined with the
gusty east winds, may lead to Red Flag Warning conditions. Potential
for heightened fire weather danger will continue to be
monitored. -Batz/Alviz


&&

.AVIATION...Satellite imagery shows the cloud cover inland
dissipating quickly and the coastal terminals losing their fog
from this morning. Winds are going to be northerly, increasing in
speed over the next few hours. Along the coast and the Willamette
Valley winds will be strongest with gusts up to 25 kt. Confidence
is low in the exact start time of the winds, but generally after
20Z Friday. VFR conditions over the next 24 hours. Overnight IFR
to LIFR CIGs and VIS will return over the coastal terminals.
15-25% chance of MVFR CIGs after 13Z Sat north of KUAO.

PDX AND APPROACHES...VFR through the period. Increasing northerly
winds in the afternoon. End time is estimated but if temperatures
drop sooner then winds will dissipate faster. Overnight there is
a 25-25% chance of MVFR CIGs redeveloping. -Muessle

&&

.MARINE...UPDATE: Have extended the Dense Fog Advisory until 1400.

Currently marine fog over much of the inner coastal waters,
resulting in visibility dropping below 1 NM.

North/northwest winds across all waters will 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. Small Craft Advisory still on track for
Zones PZZ273, PZZ253, PZZ272, and PZZ252 starting Friday morning
and continuing through at least early Saturday morning. On-and-off
Small Craft Advisory conditions through the weekend afterwards.
-42/JLiu

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Extreme Heat Watch from Tuesday afternoon through Wednesday
     evening for ORZ108>115-119>122.
WA...Extreme Heat Watch from Tuesday afternoon through Wednesday
     evening for WAZ204>207-209-210.
PZ...Dense Fog Advisory until 2 PM PDT this afternoon for
     PZZ251>253.
     Small Craft Advisory from 2 PM this afternoon to 11 PM PDT
     this evening for PZZ252-272.
     Small Craft Advisory until 2 AM PDT Saturday for PZZ253-273.
&&

$$

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