Happy Valley, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

364
FXUS66 KPQR 062059
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
1259 PM PST Fri Mar 6 2026

.SYNOPSIS...Light widespread rain today transitions to isolated
showers in the terrain and far northern Oregon/SW Washington on
Saturday. Mild temperatures near to slightly above seasonal
normals over the weekend. Colder air moves in from the north
early next week, bringing low chances for low elevation
rain/snow mix and light to moderate Cascade snow. Then, a non-
impactful atmospheric river takes aim at northern Oregon and
Washington Wednesday into Thursday, pushing out the cold air and
bringing the return of widespread rain.

&&

.DISCUSSION...Friday afternoon through Thursday...Radar imagery
Friday afternoon shows a band of light rain moving through much
of NW OR and SW WA as a weak front approaches the coast.
Although high pressure is set up over the eastern Pacific, the
Pacific NW remains on the eastern periphery of the flow, which
is allowing moisture to continue streaming into the area from
the north into the weekend. Once again daytime temperatures
will be below normal for early March, peaking right around 50
degrees for the interior lowlands, low 50s along the coast, and
low 40s to upper 30s over the Cascades. As high pressure over
the eastern Pacific spreads east into the Pacific NW tonight
into Saturday, the front will push to the north, also pushing
precipitation chances north. Mostly dry weather is expected for
Saturday, though can`t rule out a few stray showers along the
coast, Cascades, and inland locations north of Highway 20,
especially in SW WA. Temperatures will also warm around 8-10
degrees on Saturday, peaking in the upper 50s to low 50s for the
interior lowlands, just slightly higher than normal (which is
in the mid 50s). A low pressure system moving south from Alaska
along the northern Canadian coast will cause the upper level
flow to become zonal over the PacNW on Sunday. This will allow a
weak front to push south through the Pacific NW on Sunday along
with another round of widespread light precipitation.
Temperatures will lower around 5 degrees, peaking in the mid 50s
for the interior lowlands.

A bit of a pattern change is expected early next week due to
cold air intrusion into the region, leading to the potential for
low elevation snow. Ensemble guidance remains in good agreement
that cold air from Canada will funnel into the PacNW behind the
front, especially as the upper flow continues deepening
slightly Monday into Tuesday. About 75% of the GEFS, EPS, and
GEPS members indicate 850 mb temperatures falling to -4 to -6
degrees C or colder by early Monday morning at PDX with nearly
80% of the members falling to -6 to -8 degrees C or colder
Monday night into early Tuesday. Additionally, precipitation
chances continue Monday into Tuesday as moisture continues
streaming over the eastern Pacific ridge, and a weak shortwave
along the flow pulls that moisture south into the region.
Daytime temperatures each day will be well above freezing in the
lowlands, so the main time period for any lowland snow
potential is in the late overnight to morning hours when
temperatures are the coldest.

Snow levels will likely fall to around 1500-2500 ft by Monday
morning as the cold air pushes into the region. For elevations
lower than this, on Monday morning, there`s only a 10-25% chance
of low temperatures falling to freezing for elevations below
500 ft, though there is a 25-50% chance for elevations above 500
ft. However, precipitation chances are expected to be showery
and light, leading to low probability (less than 10% chance) for
any accumulating snow. Coldest temperatures are expected late
Monday night into Tuesday morning with a 50-70% chance of
temperatures falling below freezing for elevations below 500 ft
except for the Portland metro area (not including Vancouver),
where probabilities are closer to 10-25%. Above 500 ft,
probabilities increase to 70-90% chance. However, there are
also lower chances for precipitation with light accumulations
during this time, except for in the Cowlitz Valley. This is
leading to only a 5-20% chance of 0.1 inch of snow for the
Portland/Vancouver metro area and south, except for up to 30%
chance for elevations above 500 ft. Chances increase to 30-45%
for the Cowlitz Valley. Probability of 1 inch of snow is now
less than 5% for locations below 1000 ft, except for 10-20% in
the Cowlitz Valley. The other thing to take into account is road
temperatures will likely be on the warm side since overnight
temperatures will be in the 40s leading up to early next week.
This will make it difficult for snow to accumulate on roadways
as it will likely melt on contact. Ultimately, the most likely
scenario is no accumulating snow below 500-1000 ft, though some
snowflakes or slushy rain may be observed.

Higher chances for snow are expected for elevations above
1000-1500 ft Monday into Tuesday, including the Coast Range,
Willapa Hills, Cascade foothills, and Cascades. However, limited
precipitation amounts lead to limited snow forecast over the
majority of these areas. At this point, accumulating snow looks
to be mainly for locations north of Highway 20, with a 40-60%
chance of snow reaching 6 inches in 48 hours ending at 5 AM on
Wednesday. The far northern Oregon Cascades and SW Washington
Cascades are forecast to receive more precipitation. These
locations have an 80-95% chance of at least 6 inches of snow and
a 60-80% chance of at least 12 inches of snow in the same 48
hour timeframe.

On Wednesday, moisture associated with a non-impactful
atmospheric river will begin pushing into the region, pushing
out the colder air mass as widespread precipitation returns to
the region. Quite a bit of uncertainty remains in the timing of
both the steady precipitation initiation as well as when the
colder airmass begins warming. This is leading to a 20-40%
chance for morning low temperatures below freezing for lowland
locations outside of the Portland metro area (which has a less
than 10% chance). This is once again leading to the potential
for a rain/snow mix for some locations below 1000 ft, but
similar to Monday, there is low chance for accumulating
snow at the lower elevations. As the warmer air associated with
the atmospheric river moves inland, snow levels are expected to
rise above 4500-5000 ft by Wednesday evening. Additional
moderate to heavy snow is possible in the SW Washington Cascades
Thursday into Friday, but not much else south of this.

In terms of other impacts, rain amounts will be steady, but
flooding is not expected with this event. Current 48 hour rain
totals ending 5 AM Friday are 0.5-1.5 inches for the interior
lowlands and 0.75-2.5 inches for the coast, Coast Range, and
Cascades. Higher rain amounts in general are expected to be
north of Highway 20 as current guidance suggests the atmospheric
river will aim towards far northern Oregon and Washington.
Additionally, winds could get a little breezy at times, though
potential for impactful winds has gone down. There`s now only a
5-20% chance for wing gusts of at least 35 mph for inland
valleys and 20-35% chance for wind gusts of at least 40 mph for
coastal communities. Next week is shaping up to be active, so
keep an eye on the forecast! -03

&&

.AVIATION...Moist, north to northwest flow aloft continues today
as a weak front pushes across the region. This will maintain
light, steady rainfall at local terminals while conditions are
expected to gradually deteriorate through the day and into
tonight. Expect conditions to continue to trend toward
predominately MVFR this afternoon as the front continues to push
inland and CIGs lower. There is around a 20-40% chance of IFR CIGs
after 22-00z at interior lowland terminals due to the potential
for both lowering CIGs and reduced VISBY. Higher chances (50-60%)
for IFR along the coast after 00-03z Saturday. Winds generally
remain southerly around 5-10 kt.

KPDX AND APPROACHES...As of 21z, MVFR conditions are in place
with CIGs around 1500 ft and light rain reducing vsbys slightly.
Expect these conditions to persist near the lower end MVFR, with
around a 20-30% chance of IFR conditions after 22z this afternoon.
Southerly winds around 4-7 kt expected to persist through the
period. /DH

&&

.MARINE...A weak cold front will push across the coastal waters
today, bringing southwest to westerly winds with gusts up to 15
kt. A persistent northwesterly swell will maintain seas at around
6 to 8 ft at 10-11 seconds through Saturday. Another weak front
will drop across the coastal waters on Sunday, with northwest
winds behind the front likely producing gusts up to 20 kt, though
there is about a 30-50% chance that winds reach Small Craft
Advisory criteria, highest across the northern waters. The
northwest swell is also expected to increase slightly, building
seas to around 8 to 10 ft into Monday. A progressive weather
pattern continues, with the potential for a stronger system
arriving to the coastal waters by the middle of next week. At this
time, there is around a 40-50% chance for Gale force wind gusts on
Wednesday. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.
&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
x.com/NWSPortland