Happy Valley, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

423
FXUS66 KPQR 250559 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
958 PM PST Wed Dec 24 2025

...Updated aviation and marine discussion...

.SYNOPSIS...the low pressure system that brought breezy winds
has since exited the area with lingering showers. Isolated gusty
conditions with passing rain. Another low pressure system will
spin off of the coast ushering in more rain to the region.
Slight wind increases in the southern Willamette Valley in the
afternoon. Friday will bring Cascade snow followed by ridging
for the remainder of the forecast. Cold overnight temperatures
expected Saturday and Sunday.

&&

.SHORT TERM...Now through Friday Night...The low pressure system
that was slated to bring the gusty winds today ended up tracking
in an unfavorable direction for strong winds. However, that
meant that the impacts from strong winds were not widespread.
Still continued to see gusts around 30-35 mph in the interior
valleys, with strong easterly winds this morning through the
Columbia River Gorge. Behind the low, showers continue to fall
with breezy outflow winds. Cannot rule out an isolated gust up
to 40 mph or so, but not expected to be widespread.

A closed low pressure system will move eastward on Thursday,
moving over the OR/CA border by Friday morning. This low will
remain nearly stationary just offshore which will increase the
pressure gradient in the area. while some models suggest another
round of breezy winds, the overall pattern is not nearly as
favorable. In addition, there is not as much direct support
aloft for this system which will make it more difficult to
deepen fully to the extent to warrant wind headlines.

By Friday, this low will make its leap inland with strong
onshore flow developing. Weak shortwaves embedded in the flow
around the low will move up and over the Cascades with the
heaviest precipitation expected within the Oregon Cascades.
Given the cooler temperatures, lowering snow levels, and added
precipitation, we will see a trend towards advisory level snow.
6-11 inches of snow is expected along the Cascades above 4000
ft. Because Friday will be an active travel day with breezy
winds up to 40 mph, and accumulating snow at the passes, have
issued a Winter Weather Advisory for this snowfall. Heaviest
snow will be above pass level. Snow will begin to taper late
into Saturday morning with lingering snow showers persisting
Saturday morning. -27


.LONG TERM...Saturday night through Wednesday...High pressure
begins to build in on Saturday which will a)erode the low from
Friday, and b) clear skies causing temperatures to drop.
Overnight Saturday into Sunday, temperatures will fall to or
near freezing temperatures. There is around a 90% chance of
temperatures below freezing within the southern Willamette
Valley, near 70% in the northern Willamette Valley and around
15% in the Portland-Vancouver Metro area. The coast also has a
non-zero chance of seeing freezing temperatures Sunday morning.
The probability of 25 degrees is far less with less than a 10%
chance within the southern Willamette Valley and less than 3%
chance elsewhere. During the day, conditions will be dry and
clear.

Similar conditions expected on Monday and Tuesday mornings with
slightly warmer conditions each day.-27


&&

.AVIATION...Satellite imagery and terminal observations as of late
Wednesday evening show mostly VFR conditions with some patchy fog
development across the Willamette Valley. Clearing skies and calm
winds will favor fog development across the Valley through 12z Thu,
leading to LIFR VIS/CIGs. Conditions should remain VFR along the
coast as offshore flow prevails. After 10-12z Thu, a low pressure
system offshore will increase shower activity from south to north.
Mixing will increase, dissipating fog and improving conditions back
to MVFR/VFR. Shower activity decreases after 18-20z Thu with
predominately VFR CIGs. Guidance suggests a 20-40% chance for MVFR
CIGs throughout the day Thursday, mainly for the Valley. Easterly
winds along the coast and Portland/Vancouver Metro remain under 10
kt, with light northwesterly winds elsewhere. Winds turn more
southerly tomorrow, with gusts up to 20 kt along the central Oregon
coast.

KPDX AND APPROACHES...LIFR VIS/CIGs due to fog through 12z Thu.
After 12z Thu, increasing shower activity due to low pressure will
scatter out fog and improve conditions back to VFR. Predominately
VFR conditions 12z Thu through the end of the TAF period, with a 20-
40% chance for MVFR CIGs between 18z Thu-00z Fri. Easterly winds
around 5-10 kt.      -10


&&

.MARINE...Easterly winds will increase over the waters tonight
as another low pressure system approaches from the southwest. The
east winds will gust up to 25 kt beyond 10 NM. The winds will turn
southeasterly and strengthen Thursday morning as the low nears. A
Gale Warning has been issued for the waters south of Cape Falcon and
beyond 10 NM for southeasterly wind gusts up to 40 kt. Elsewhere,
Small Craft Advisories remain in effect for wind gusts up to 30 kt.
Seas also build on Thursday due to a combination of wind waves and a
southerly swell. Seas within the Gale Warning may build to 18-22 ft
at 10-12 sec, while other locations build to 13-16 ft at 11-12 sec.
Hazardous seas and small craft conditions continue into Friday
before marine conditions settle down this weekend.       -11/10

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Winter Weather Advisory from 4 AM Friday to 4 PM PST Saturday
     for ORZ126>128.

WA...None.
PZ...Small Craft Advisory from 10 AM Thursday to 4 AM PST Friday for
     PZZ251>253.

     Small Craft Advisory from 1 AM to 7 PM PST Thursday for PZZ271.

     Hazardous Seas Warning from 7 PM Thursday to 4 AM PST Friday
     for PZZ271.

     Small Craft Advisory from 1 AM to 10 AM PST Thursday for PZZ272-
     273.

     Gale Warning from 10 AM to 10 PM PST Thursday for PZZ272-273.

     Hazardous Seas Warning from 10 PM Thursday to 4 AM PST Friday
     for PZZ272-273.

&&

$$

www.weather.gov/portland

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