199
FXUS66 KPQR 230255 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
655 PM PST Fri Nov 22 2024

.SYNOPSIS...Another round of rain showers and wind today,
windiest at the coast. Rain showers and mountain snow showers
over the weekend into early next week. Trending towards drier
weather later next week with seasonable temperatures.

&&

.DISCUSSION...Today through Thursday...Warm front is currently over
the Cascades as of 1:30 pm Fri, with most of the area seeing
post- frontal showery activity. Winds at the north coast are
currently seeing peak gusting up to 50-60 mph; for areas further
south, winds will be slowly decreasing as the low moves further
and further north towards Washington/Canada. Inland, the
central Willamette Valley saw peak gusts around noon of 35-45
mph winds; these too will be on the decline over the next few
hours. Main impacts from wind are broken tree branches and
perhaps some trees in soggy ground become uprooted, potentially
resulting in power outages and other damage. Any remaining rain
accumulations associated with this front will be fairly light;
around 0.10-0.20" for most areas, and around 0.5" for the
Cascades and Coast Range.

The possibility for coastal thunderstorms continues this afternoon
going through Sunday. Conditions still support a very low chance
(<5%) of some isolated waterspouts over the waters. Any heavier
thunderstorms still see the possibility of producing small hail and
bursts of heavier rain as well at the coast.

Snow levels are currently quite high (7000-8000 ft) following this
warm front, but will continue falling overnight tonight. Snow levels
likely fall to around 3000-3500 ft by Saturday morning. Snow amounts
during this time look to be around 1/2 foot at passes Friday night
to Sunday afternoon (48 hours), and closer to 1 ft for the volcano
peaks. At this time no winter headlines are expected.

The next wave of moisture from the parent low arrives Saturday in
the late afternoon, bringing another round of steadier rain to the
area.
Looking at 24 hr rainfall between 10am Sat and 10am Sun, only around
a 25% chance of exceeding 0.5" in the Willamette Valley. The coast
and Coast Range see slightly better rainfall, somewhere around 0.5-
1.5" of rain. Winds won`t be nearly as strong inland, with less than
10% chance of gusts over 25 mph anywhere inland. At the coast, gusts
right around 25-30 mph will be possible throughout Saturday night
and Sunday morning, decreasing afterwards.

Light weak showery activity continues through the beginning of next
week, without any particularly impactful weather expected. WPC
Cluster Analysis shows strong agreement (90%+) of upper level riding
moving in by Wednesday night, likely producing drier and warmer
weather. /JLiu

&&

.AVIATION...A low pressure system offshore has resulted in gusty
southerly winds over northwest Oregon and southwest Washington on
Friday, with the highest winds observed along the coast. This low
will continue moving northward towards Vancouver Island Friday
afternoon and evening. As the system exits the region around 00Z
Saturday, will see post-frontal showers spread from south to
north during the overnight hours with predominately VFR
conditions. Winds will also begin to weaken after 00-03z Saturday,
both inland and at the coast. Chances for MVFR cigs increase to
20-50% between 09-15z Saturday, however widespread MVFR cigs are
not expected.

PDX APPROACHES...VFR conditions expected Friday afternoon through
Friday night with a period of breezy southeast winds continuing
through 01z Saturday with gusts up to 20-25 kt. Winds weaken
thereafter while veering to the south. There is around a 50%
chance for MVFR cigs to develop over the terminal by 12-13z
Saturday, however probabilities decrease to 20% by 18z Saturday
when VFR cigs are likely to return.  -TK

&&

.MARINE...A strong low pressure system centered around 100-150
miles offshore continues to bring steep and hazardous seas along
with strong southerly winds for the coastal waters. Buoy
observations from 1-2 PM Friday showed seas around 20 ft over
the northern waters and around 15 ft over the southern waters.
Winds were generally gusting between 35-45 kt with occasional
storm force wind gusts. Although seas and winds are elevated at
the moment, expect both seas and winds to begin rapidly
decreasing Friday evening through Friday night as the
aforementioned low pressure system continues moving northward
towards Vancouver Island. By 10 PM Friday, seas should range
between 12 to 15 ft, highest over the northern waters beyond 10
nm offshore. Winds will likely be gusting between 20-30 kt at
that time, with isolated gusts to 35 kt over the northern
waters. By sunrise on Saturday, seas should be around 10 feet
with wind gusts under 30 kt.

Beyond Saturday, the weather pattern becomes relatively benign
for this time of year with no signs of significant winds or
hazardous seas. The only exception to that statement is Saturday
night and Sunday when a brief period of stronger winds is
expected as a weak small-scale surface low moves north over the
coastal waters. There is still some uncertainty regarding how
strong winds will get with this low, but as of right now it
appears wind gusts up to 30-35 kt are likely. However, cannot
completely rule out gusts as high as 40 kt (30-40% chance). Given
the short duration of these stronger winds, seas are not expected
to have enough time to build much beyond 10-12 ft. The probability
for seas over 12 ft is only around 10-20% at this time. -TK

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Gale Warning until 10 PM PST this evening for PZZ210-251-252-
     271-272.
     Hazardous Seas Warning from 10 PM this evening to 4 AM PST
     Saturday for PZZ210-251-252-271-272.
     Hazardous Seas Warning until 4 AM PST Saturday for PZZ253-273.
&&

$$

www.weather.gov/portland

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