024
FXUS66 KPQR 191110
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
310 AM PST Sun Jan 19 2025

.SYNOPSIS...High pressure will remain in place through next
week, maintaining dry conditions, mostly sunny skies, and chilly
overnight temperatures. Could see some increased cloud cover
Monday night into Tuesday as a dry front approaches the area.
Guidance suggests high pressure breaks down Thursday to Friday,
with potential return for precipitation. High uncertainty
remains with this system at the end of the week.

&&

.SHORT TERM...Now through Tuesday Night...Upper level pattern
remains largely unchanged over the last 24 hours with deep
troughing over the continental US and a narrow, amplified ridge
axis just off the West Coast. Clear overnight conditions
supporting efficient radiative cooling with inland lows dropping
below the freezing mark for most locations. Drier conditions
are keeping stratus and fog from developing except for the far
southern Willamette Valley around Eugene which seeing patchy
dense fog. Expect another quiet and dry day to end the weekend
with inland temps reaching into the low to mid 40s, coastal
areas could see temps closer to the 50 mark while the Cascades
will stay in the 30s.

The offshore ridge axis will shift inland late Sunday into Monday,
leading to another clear and cold night across the region. Many
locations west of the Cascades are expected to drop into the low to
mid 20s, slightly warmer around metro in the upper 20s and along the
coastal areas. A Cold Weather Advisory remains in effect for areas
west of the Cascades and throughout the Columbia River Gorge and
Upper Hood River Valley.

Monday will be dry and mostly sunny as the ridge shifts overhead,
but an approaching upper level shortwave trough will return high
cloud cover by Monday night. The shortwave is not expected to bring
any precipitation to the area. Overnight lows will still be chilly
Monday night into Tuesday morning but confidence is lower for
meeting Cold Weather Advisory criteria as cloud cover could keep
temperatures a few degrees warmer. High pressure rebuilds behind
this trough, clearing skies by Tuesday afternoon. -Batz


.LONG TERM...Wednesday through Friday...The majority of
ensemble members from the WPC cluster analyses are in agreement
on upper level ridging continuing Wednesday, maintaining dry
weather with mostly clear skies and chilly nights. On Thursday,
the clusters all begin to show the ridge beginning to weaken as
a system begins to dip southward from Canada. Thursday night to
Friday, about 75% of ensemble members show the ridge completely
breaking down or shifting eastward. This would return chances
for precipitation at the end of the week, however, there is
still high uncertainty with the exact timing, magnitude, and
track of this potential system. -Alviz

&&

.AVIATION...Generally clear skies and VFR across the area, with
the exception of fog in the southern Willamette Valley (KEUG).
Weak northeasterly flow throughout the region, continuing through
Sunday, bringing dry cold air that should generally inhibit fog
formation. Fog at KEUG should begin lifting around 18-20z Sunday,
after which VFR conditions will return for the majority of daytime
hours. KTTD also will be an exception, with easterly flow through
the Columbia River Gorge increasing throughout the period.
easterly winds with gusts up to 25 kt possible after around 03-05z
Mon. Otherwise, most terminals see clear skies and weak
northeasterly flow under 8 kts throughout the period.

PDX AND APPROACHES...VFR throughout the period, with generally
weak northeasterly flow turning easterly during daytime hours on
Sunday. Winds remain under 10 kt throughout the period, however.
Clear skies for the duration of the TAF period. /JLiu

&&

.MARINE...Light to moderate north-northeast breezes persist across
the coastal waters this afternoon as high pressure remains
anchored offshore, with winds remaining under 15-20 kt for the
foreseeable future. Little change expected through the weekend as
high pressure persists. Long period swell entering the waters at
around 7 ft at 20 seconds; this rises to 8-9 ft at 18 seconds
through Sunday evening. Afterwards waves come back down slowly
over the next few days. Winds shift more offshore early next week,
with a few stronger gusts possible in the nearshore waters out of
gaps in the coastal terrain. Generally benign conditions expected
to persist well into next week as seas reside in the 5-7 ft range
dominated by mid period westerly swell at 13-15 seconds. /CB/JLiu

&&

.BEACH HAZARDS...A long period westerly swell continues to impact
the region, with seas at 7 ft around 20 seconds as of 3am Sunday.
Enhanced sneaker wave threat at beaches until Sunday night as
the swell persists at 7-9 ft at 18-20 seconds. Beachgoers should
remain vigilant for waves occasionally running up much farther
onto the beach than background wave conditions. Stay off of
rocks and jetties and never turn your back to the ocean. /CB

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Cold Weather Advisory from 10 PM this evening to 10 AM PST
     Monday for ORZ101>125.

WA...Cold Weather Advisory from 10 PM this evening to 10 AM PST
     Monday for WAZ201>210.

PZ...None.

&&

$$

www.weather.gov/portland

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