695
FXUS66 KPQR 131743 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1043 AM PDT Sun Jul 13 2025

Updated aviation, marine and hazards.


&&

.SYNOPSIS...A Heat Advisory remains in place today for most
interior valleys. Expect sunny skies across the area with
morning marine stratus/fog along the coast. Temperatures cool
slightly on Monday, but still remain warm and dry. An Extreme
Heat Watch continues for some interior valley locations from
Tuesday to Wednesday, as afternoon temperatures between 90 to
100 degrees and low temperatures between 65 and 70 degrees are
possible.

&&

.SHORT TERM...Now through Monday Night...Today`s temps are
forecast to jump up a few degrees from Saturday as the upper
ridge persists and the overall airmass continues to warm- up.
850 mb temperatures are expected to increase to 20-23 C and will
mix down to the surface on Sunday, leading to high temperatures
in the mid to upper 90s for interior valleys. There is a 20-40%
chance for a few locations throughout the Willamette Valley to
reach 100. Expect widespread Moderate HeatRisk, which means that
this level of heat affects most individuals sensitive heat,
especially those without effective cooling and/or adequate
hydration. A Heat Advisory is in effect across the Willamette
Valley, Portland/Vancouver Metro Area, Columbia River Gorge,
Upper Hood River Valley, and lower Columbia-Cowlitz County
lowlands from 11 AM Sunday to 10 PM Sunday. Take necessary heat
precautions as hot temperatures may lead to heat illnesses.

Onshore northwest to northerly winds will again increase during the
afternoon as surface high pressure offshore and low pressure east of
the Cascades increases the pressure gradient. Expect wind gusts up
to 20-25 mph inland, while gusts up to 30 mph will be possible along
the central Oregon coast.

The upper ridge axis retrogrades over the Pacific as an upper level
trough drops out of British Columbia into Washington on Monday. This
will likely push 850 mb temps back down into the mid-teens,
resulting in surface temperatures cooling around 10 degrees, toward
near normal values for July. Could also deepen the marine layer
along the coast enough to push up the lower Columbia into the
Portland metro by Monday morning. -Batz/DH

.LONG TERM...Tuesday through Saturday...Tuesday and Wednesday
remain the hottest days next week. Deterministic values for
Tuesday have come up a bit but the 10th- 90th percentile spread
for Tuesday remains around 10 degrees across the inland valleys,
generally from low 90s to around 100. Deterministic highs on
Wednesday remain in the mid to upper 90s inland. The spread
between the 10th-90th percentiles has shrunk, ranging from the
low 90s to low 100s.

The latest guidance suggests a 20-50% chance that temperatures reach
100 degrees or hotter across the Willamette Valley on Tuesday.
Tuesday night low temperatures between 65 and 70 degrees are
expected especially around the Portland/Vancouver Metro Area and
Columbia River Gorge. Guidance suggests a 40-70% chance that Tuesday
night lows remain above 65 degrees and a 20% chance low temperatures
remain above 70 degrees, which would limit overnight relief. Will
continue the Extreme Heat Watch for now, though NWS HeatRisk
continues to trend toward widespread Moderate Risk rather than Major
Risk.

Days 6 and 7 in this forecast continue the large uncertainty trend
with potential for a big cool down or another day of hot conditions
on Thursday. Deterministic values are suggesting low to mid 90s
throughout the inland valleys but the 10th-90th percentile spread is
significant, ranging from upper 70s to low 100s. Ensemble
guidance is really struggling with the pattern for the latter
half of next week with a 50/50 split between troughing or weak
ridging across the PacNW. Model spread should decrease as the
lead time becomes shorter. Guidance does show higher confidence
of temperatures trending into the mid-80s by next Saturday with
dry conditions persisting. -Batz

&&

.AVIATION...General area of high pressure to the west. Satellite
shows upwelling along the coast promoting IFR and LIFR VIS and
CIGs this morning. Will continue to see these conditions in the
vicinity of some coastal terminals even though observations are
showing it dissipate. Continue to be alert for this patchy dense
fog. Inland, VFR through the next 24 hours. Northerly winds through the day with gusty winds in the
afternoon.

On Monday, conditions will shift as a weak shortwave passes over.
Will start to see cloud cover develop overnight where there is
around a 40% chance of MVFR CIGs along the Columbia River
extending into KTTD and down the Willamette Valley north of KUAO.
Will still see clouds forming aloft, but generally to the north.
In addition, there is another chance for fog to reform along the
coast.

PDX AND APPROACHES...VFR conditions persist through the TAF
period. Expect northerly to northeasterly surface winds less than
10 kts with wind gusts aloft between FL015-FL025 up to 25 kt.
These winds will likely mix down to the surface and thus increase
winds. There is around a 50% chance of gusts up to 25 kt.
Overnight there is a 40% chance that MVFR CIGs will develop.
However, given the depth of dry air it will be difficult to form.
If it does it would be for a short period of time. -Muessle

&&

.MARINE...Upwelling along the coast is keeping marine stratus in
place with marine fog expected through this morning. A Dense Fog
Advisory remains in effect for the inner waters and Columbia Bar
with visibility of 1/2 NM or less expected through Sunday early
afternoon. Confidence is low in the exact dissipation time frame
due to the unpredictable nature of the upwelling.

Strong high pressure over the waters continues into midweek. A
strengthening thermal trough over western CA and OR is tightening
pressure gradients, causing gusty north winds into Monday.
Strongest winds will be today with gusts up to 25 kts for the
waters north of Cape Falcon and up to 30 kts for the waters south
of Cape Falcon. A Small Craft Advisory is in effect for all
waters. Seas remain around 7-9 feet at 10 seconds through Monday
afternoon, though seas could briefly raise to 10 feet for the
outer waters Monday night into Tuesday morning. -Muessle/HEC

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory until 10 PM PDT this evening for ORZ108-109-111-
     112-114>118-120>122.
     Extreme Heat Watch from Tuesday afternoon through Wednesday
     evening for ORZ108>115-119>122.
WA...Heat Advisory until 10 PM PDT this evening for WAZ204>207-209-
     210.
     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 PZZ210-
     251>253.
     Small Craft Advisory until 5 AM PDT Monday for PZZ251>253-
     271>273.
&&

$$

www.weather.gov/portland

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