644
FXUS66 KPQR 041703 AAA
AFDPQR

Area Forecast Discussion..UPDATED
National Weather Service Portland OR
1003 AM PDT Fri Apr 4 2025

Updated Aviation Discussion

.SYNOPSIS...Warm and dry weather expected through Saturday with
high pressure over the region. Cooler and wetter weather returns
Sunday into early next week. No significant weather concerns
within the next seven days.

&&

.DISCUSSION...Satellite imagery reveals clear skies over the
region early Friday morning, which has allowed temperatures to
drop into the 30s overnight across the interior valleys of
northwest Oregon and southwest Washington. A Frost Advisory
remains in effect until 9 AM this morning for most of these
locations as temperatures bottom out in the low to mid 30s
around sunrise. The exception will be the coast and the
Portland/Vancouver metro where temperatures will stay a bit
warmer in the upper 30s to low 40s. After the chilly start
today, temperatures will warm well into the 60s across most of
the area this afternoon as a highly amplified upper level ridge
builds over the region from offshore. NBM probabilistic
guidance continues to give the Portland area around a 50/50
chance to reach 70 degrees this afternoon, with closer to a
10-20% chance elsewhere in the Willamette Valley. Do not
anticipate any further frost concerns tonight as overnight lows
increase into the 40s across most of the area. Saturday remains
on track to be the warmest day of the week as the ridge axis
moves directly overhead, with most interior valley locations
likely to reach 70 degrees (70-90% chance). The warmth will not
extend to the coast as continued marine layer influence keeps
those locations more mild into the weekend.

The warm and dry stretch comes to an end on Sunday as the ridge
shifts east of the Cascades and allows the next front to move
into the region, dropping temperatures back into the low to mid
60s and bringing the next round of widespread rain to the area
beginning Sunday afternoon. Expect seasonably mild and wetter
weather to then persist through the middle of next week as
ensemble clusters indicate upper level troughing over the NE
Pacific and Pacific NW. NBM guidance depicts a 15-20% chance of
thunderstorms across much of the area on Monday as colder air
arrives over the region in association with the upper level
trough. Otherwise, expect mostly benign weather through the end
of the period as daytime highs hover close to seasonal norms in
the upper 50s and precipitation remains sporadic and light
enough to minimize any hydro concerns. /CB

&&

.AVIATION...Widespread VFR under mostly clear skies for all
terminals through the TAF period. Expect easterly to northeasterly
winds generally less than 10 kt across most terminals today.
However, easterly winds are expected to increase as the day
progresses. This will likely result in easterly gusts up to 25 kt
impacting KTTD and this will also bring predominately easterly
winds to KPDX. Also, KONP and locations southward, will see some
terrain focusing of easterly winds as well, which will maintain
gusts up to 25 kt. These gusty, easterly winds are expected to
persist as a weak thermally induced trough will persist through at
least the TAF period.

The KAST anemometer remains inoperative. Therefore, KAST TAFs are
limited to CIG and VIS.

PDX AND APPROACHES...VFR under clear skies. Light and variable
winds will become easterly around 19Z-22Z Friday and will persist
through the remainder of the TAF period. /42

&&

.MARINE...High pressure building over the Pacific Northwest will
maintain benign marine conditions today into Saturday. With higher
pressure inland and lower pressure offshore, expect easterly to
northeasterly winds around 5 to 10 kt today. Seas remain around 3
to 5 ft at 8 seconds through Saturday.

Winds will shift southerly around 10 to 15 kt Saturday morning
ahead of the next approaching front. This front will push through
Saturday night into Sunday, strengthening southerly winds. There
is a 30 to 50 percent probability for Small Craft level wind gusts
up to 25 kt with the frontal passage Saturday night into Sunday
morning. A west-southwesterly swell will also push through the
waters during this time, building seas to 6 to 8 ft at 10 seconds
by late Saturday night and 11 to 13 ft at 17 seconds by Sunday
afternoon. This swell will increase the threat for sneaker waves
on Sunday.

Active weather continues early next week with a stronger front
forecast late Monday night into early Tuesday morning. Guidance
currently suggests a 40 to 60 percent probability for Gale force
wind gusts up to 35 kt with this stronger front.       -Alviz

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

www.weather.gov/portland

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