676
FXUS66 KPQR 132106
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
206 PM PDT Sun Apr 13 2025

.SYNOPSIS...High pressure will dominate the weather pattern
through the week with dry conditions and above normal temperatures;
perfect for those hoping to get outdoors. So, if you enjoy
being in the garden, playing pickleball or something else under
the sun, then you are in for a glorious week. Just remember to
wear sunscreen and hydrate. Currently, the hottest days during
this stretch appears to be Monday with high temperatures easily
reaching into the mid to upper 70s across the interior valleys.

&&

.SHORT TERM...Tonight through Tuesday Night...A Rex Block
pattern has enveloped the majority of the west coast, with our
region under the expansive area of high pressure of said Rex
Block, with the low centered off the coast of central/southern
California. The ridge axis of the high pressure will continue
to slowly move eastward through the start of this week. As this
blocking pattern develops, a thermally induced surface trough
will also develop within the Willamette Valley. Current guidance
has the surface trough axis falling along or just west of the
Coast Range. This scenario will enable warm, dry air to
infiltrate into the Willamette Valley from the Great Basin for
the start of the week. This set up will result in clear skies
with daytime highs on Monday reaching into the mid to upper 70s
for Willamette Valley/I-5 corridor locations and mid 60s to mid
70s elsewhere. Given weak warm advection aloft and the surface
thermal trough overhead it would not be surprising to see a spot
or two in the Willamette Valley or lower Cascade valleys to
crack 80 degrees even though the NBM only gives a 10-15%
probability to do so.

Tuesday,the ridge axis of the Rex Block should be well to our
east. This will bring about weak onshore flow, and lowering
upper-level heights as a Canadian trough will help to
destabilize the blocking pattern and this will bring about a
slight cooling trend for the middle of the week. Clear skies
will still be present, but daytime highs on Tuesday will be
around 3-5 degrees cooler across the forecast area.

.LONG TERM...Wednesday through Sunday...Most ensemble members
(75%) from the GEFS, ENS, and GEPS are in general agreement of
an upper level trough moving southward from the Canadian Rockies
into the Intermountain West on Wednesday. This trough along
with a persistent upper level ridge over the northeast Pacific
will generally lead to northerly flow over northwest Oregon and
southwest Washington. Expect predominately dry and slightly
cooler conditions on Wednesday, with only a 5-10% chance that
the aforementioned trough tracks west enough to bring measurable
precipitation (mainly from the GEFS). If anything, maybe a
stray shower or two over the Cascades. Meanwhile, the ENS and
GEPS keep us completely dry.

Conditions remain warm and dry through Friday as ridging
re- builds over the Pacific Northwest. Daytime highs are
forecast well- above normal, with upper 60s to mid 70s for
interior valleys and lows in the 40s. Still could see the
potential for breezy easterly winds returning late in the week,
but no impactful winds expected. The next sign of rain and much
cooler temps returns in the latter half of this weekend when
the majority of ensemble members are hinting at a shortwave
trough pushing into the region. -Alviz/Schuldt

&&

.AVIATION...VFR conditions under clear skies through the period
as high pressure builds over the region. Strengthening thermal
trough along the Cascades will tighten the surface pressure
gradient and support northerly winds of 10-15 kt at most sites
through 03-06z Mon, with easterly winds of 10-20 kt through the
western Columbia River Gorge affecting KTTD.

PDX AND APPROACHES...VFR through the period under clear skies.
North-northeast winds increasing to around 10 kt through 03z Mon,
diminishing closer to 5 kt thereafter. Easterly winds 10-20 kt
closer to the Gorge near KTTD. /CB

&&

.MARINE.... High pressure offshore will maintain a summer-like
pattern of moderate to strong northerly breezes over the waters
for much of the coming week as the developing West Coast thermal
trough helps to tighten the coastal pressure gradient. Small
Craft Advisories have been extended through Tuesday afternoon
based on latest model guidance and high degree of confidence in
the pattern. Expect some diurnal fluctuations as inland heating
helps to drive gustier winds during the afternoon and evening
hours each day.

Short period wind-driven seas and a modest westerly swell will
combine to produce choppy seas in the 5 to 7 ft range through
Monday. Building northwesterly swell arriving late Tuesday into
Wednesday pushes seas closer to 10 to 12 ft towards the middle of
the week. /CB

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Tuesday for PZZ251-252-271-
     272.

     Small Craft Advisory until 5 AM PDT Tuesday for PZZ253-273.

&&

$$

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