000
FXUS66 KPQR 260934
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
229 AM PDT Fri Apr 26 2024

.SYNOPSIS...Showery and unsettled conditions continue through
the weekend and into next week as the Pacific Northwest remains
under the influence of a rather progressive spring-time weather
pattern. Beyond the more persistent chances for rainfall going
forward snow levels are expected to hold near 4500ft today, with
light accumulations expected. Still challenging to see next week, as
8-ball is rather hazy. But, could see a dry day for Wed before more
precipitation returns afterwards.
&&

.SHORT TERM...(Today through Sunday)...Upper trough will push inland
today. This will maintain plenty of clouds and coolish temperatures.
As 2 am, NOAA satellite imagery showing two lows, one near North Bend
and the other off the north Washington coast. The low near the south
Oregon coast will push inland, and maintain showers over the region
this am. The other low will slowly drop southeast and shift inland
just south of Astoria. This will act to reinvigorate the showers this
afternoon into this evening. Overall, not as much rain today as that
seen on Thursday. Generally, will see 0.25 to 0.75 inch along the
coast (heaviest over the Coast Range/Willapa Hills), as well as most
of the Cascades. Bit less across the interior lowlands, with 0.10 to
0.25 in expected.

As for the Cascades, snow levels have been lowering slowly this am.
As of 2 am, have light snow at Santiam Pass, suggesting snow level
has lowered to about 4800 ft. Will maintain current winter weather
advisory for light snow above 4500 ft, with 1 to 4 inches expected,
though may get local amounts up to 8 inches on higher peaks/ridges.

Showers gradually decreasing later tonight, as the air mass begins to
stabilize in response to weak ridging offshore shifting inland. This
main due to another fast approaching front, which will push inland
Sat afternoon. This front will bring a band of rain to the region
later Sat am into the afternoon. Front moves onshore by late
afternoon, and pushes quickly to the Cascades by early evening. With
somewhat fast movement of this front, overall rainfall amounts will
not be all that much, with 0.10 to 0.25 inch, with heaviest along the
coast. As usual, bit higher amounts over the higher terrain, with
0.25 to 0.50 inch in spots of the Coast Range/Willapa Hills and
Cascades as far south as Mt Hood area.

Cooler showery pattern resumes for Sat night into Sun, though does
appear showers will be decreasing in coverage Sun afternoon. Snow
levels holding at 4500 to 5000 ft.       /Rockey

.LONG TERM...(Sunday night through Thursday)...Through Tue,
confidence is high the pattern stays rather progressive, with steady
westerly flow off the Pacific into the Pacific NW. Another front will
push across the region Sun night. Then, cool with showers for Mon
through Tue. Snow levels lower a tad, running 3000 to 4000 ft.

Few showers linger around region on Wed, but think most of
the day will end up being mostly dry for the inland valleys, as
a weak transient ridge glides over the region. But, models show
another potent front pushing inland late Wed night into Thu. But,
models and the magic 8-ball show continue lower confidence in overall
pattern for later next week. ECMWF continues to show cool upper
trough shifting off the Pac into the Pac NW, with lots of showers for
region. But, if the GFS wins out, will have more southwest flow
aloft, with upper trough/low over the Gulf of Alaska shifting into
western BC. In this situation, would be drier and more mild for our
area. Hmm, will not make much in way of change at the moment, but
suspect GFS may end up being the way to go.  /Rockey

&&

.AVIATION...Showers continue through Friday as an upper level
trough slides west to east across the region through the TAF
period. This will result in mountain obscuration through the TAF
period, while coastal and inland locations will see a mixture of
VFR and MVFR conditions through the TAF period. For inland
locations expect cigs between 3000-4000 and for coastal locations
expect cigs between 2500-3500 with a 30-40% probability for
intermittent IFR conditions. Southerly winds along the coast with
gusts up to 25 kt through around 00Z Saturday. Afterwards, expect
winds to become more west/northwest with gusts up to 20 kt.
Persistent southerly winds with gusts up to 15 kt for inland
locations.

Notes: The ASOS at KTTD is only available via the dial in option.
The AWOS at KMMV is still out of commission. There is no
estimated time of repair.

PDX AND APPROACHES...A mixture of VFR and MVFR conditions with
passing showers through the TAF period. Cigs between 3000-4000
along with intermittent showers. Southerly winds with gusts up to
15 kt for inland locations. /42
&&

.MARINE...Post-frontal conditions persist resulting in steep and
choppy seas. Southerly winds will continue through the afternoon.
Afterwards, winds will become more northwesterly, but this will be
somewhat short lived as the next system is expected to arrive
Friday night/Saturday morning bringing a return of southerly
winds. Therefore, have extended the current suite of Small Craft
Advisories out through Saturday morning. These conditions will
likely persist through Saturday night, but timing and exact
strength is still in flux. The Small Craft Advisory for Friday
will primarily be for steep and choppy seas around 7 to 10 ft at 8
to 10 seconds. As southerly winds return on Saturday expect gusts
up to 30 kt. The latest NBM has decreased confidence in gales,
only around 10% on Saturday. /42
&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Winter Weather Advisory through this evening for areas above
         4500 feet in the Cascades zones 126-127-128.

WA...Winter Weather Advisory through this evening for areas above
        4500 feet in the south Washington Cascades zone 211.

PZ...Small Craft Advisory until 5 PM PDT Saturday for all coastal
         waters and the Columbia River Bar.
 &&


$$

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