376
FXUS66 KPQR 091702 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1001 AM PDT Wed Jul 9 2025

Updated Aviation and Marine Discussions

.SYNOPSIS...A weak frontal system brings more seasonable
temperatures today and Thursday, with a chance for some light
rain along northern coastal areas today. Hotter temperatures
return Friday and persist into next week as strong high pressure
builds offshore.

&&

.SHORT TERM...Now through Thursday Night...A brief break from
above average temperatures today and tomorrow as a short wave
trough moves inland across western Canada. This disturbance will
send a weak cold front through the region, bringing increased
cloud cover and onshore flow. A decent marine push is expected
to move inland after 5 am and should support mostly cloudy skies
throughout the interior valleys. Temps are expected to be
closer to seasonal averages if not a few degrees below average,
topping out in the mid to upper 70s inland and upper 50s to low
60s along the coast. The cold front won`t have an abundance of
moisture associated with it but models are suggesting a light
rain along the coast and coast range from Tillamook northward to
Pacific county in WA around the Long Beach Peninsula. Rain
totals of a few hundredths to around two tenths will be
possible. Inland locations are expected to remain mostly dry
through there is a slight chance (15-20%) for rain into the
Cowlitz Valley, leading to maybe a trace up to a couple
hundredths if anything. Thursday will remain dry with temps
around average in the low to mid 80s inland and low to mid 60s
along the coast. -Batz

.LONG TERM...Friday through Tuesday...Reprieve from the heat
will be short lived as another ridge begins to strengthen over
the northeast Pacific on Friday. Cluster guidance shows very
good agreement in this pattern developing and strengthening into
the weekend and early next week. There are slight variations in
exact strength of the ridge over the PacNW but a prolonged
chances for a stretch of daily highs in the low to mid 90s
throughout the Willamette Valley look good, with potential for a
couple days next week to reach triple digits in some locations.
Probabilities for highs to reach 95 or greater from Salem to
Eugene on Friday and Saturday are 10-40% but increase to 40-70%
on Sunday and Monday. Probabilities around the
Portland/Vancouver Metro on Friday and Saturday are 10-20% and
on Sunday and Monday jump to 30- 50%. HeatRisk is expected to
remain moderate from Friday through Monday. However, the NBM is
hinting at even warming temps Tuesday and Wednesday next week
with 25-75th percentiles ranging from 90- 102 both days for
Portland and Eugene. NBM probs for reaching 100 or greater both
days throughout the Willamette Valley are 20-50%. If temps trend
toward the 75th percentile or greater then we may see HeatRisk
for these days jump into the Major category.

In terms of precipitation, certainly expect most of the area to
remain dry through the end of the long term. However, did note that
most deterministic solutions depict a mid level impulse off of
northern California this weekend and early next week, which
maintains at least a thought for a few thunderstorms in the vicinity
of the Lane County Cascades into the long term. Model probabilities
are too low to warrant inclusion of thunderstorms in the forecast
for now, but will need to monitor this potential as models start to
better resolve this feature in the coming days. -Batz/CB

&&

.AVIATION...Onshore flow continues through the TAF period and will
result in generally improving conditions through the daytime
hours, with a return of lowered flight conditions across the
airspace as a more robust marine push is expected to start around
00Z-04Z Thursday. Currently, widespread VFR conditions continue
to develop for inland locations. At the same time the mixed flight
conditions along the coast are expected to also improve towards
MVFR/IFR over the next few hours. Starting around 00Z-04Z expect a
resurgence of marine stratus to impact the coast, this will
result in IFR/LIFR conditions returning along the coast and
persisting through at least 15Z Thursday. Inland locations will
have a bit of a delay as marine stratus will have to work
in-between the gaps and flows of the Coast Range as well as snake
down the Columbia River. So, expect generally MVFR conditions for
all inland locations to start around 10Z-12Z Thursday. There is a
10-15% probability for isolated IFR conditions, with the higher
probabilities towards KEUG. Conditions are expected to improve
back towards VFR around 14Z-16Z Thursday. Winds will be out of the
north/northwest at less than 10 kt.

PDX AND APPROACHES...VFR conditions through around 10Z Thursday
as marine stratus from the Columbia River is expected to bring
MVFR flight conditions. After 15Z Thursday conditions are expected
to improve back towards VFR. Winds out of the north/northwest at
less than 10 kt. /42

&&

.MARINE...A weak frontal passage is in the process of turning winds
southeastward over the rest of tonight. Winds will be strongest
within 20 NM of the coast, particularly from Cape Falcon northward,
but there is a 75% chance that southerly wind gusts remain below 20
kt. Once the front passes, winds will turn west to northwesterly late
in the day on Wednesday.

We will then return a more typical northerly wind pattern Thursday
into Friday as high pressure builds across the northeast Pacific
and thermally induced lower pressure returns to northern
California. This will produce 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. /Neuman /JLiu

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

www.weather.gov/portland

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