Corvallis, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

112
FXUS66 KPQR 021700 AAA
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
1000 AM PDT Wed Apr 2 2025

.SYNOPSIS...One more showery day across the area today as a
weak disturbance passes overhead. Drier weather expected for
Thursday, with chilly overnight lows leading to frost potential
Friday morning. High pressure brings warmer temperatures Friday
into the weekend, with the pattern then trending back towards
cooler and wetter by early next week.

&&

.DISCUSSION...Early morning radar imagery shows isolated to
scattered shower activity ongoing across northwest Oregon and
southwest Washington in northwest flow aloft. Shower activity
will be enhanced later this morning into this afternoon as an
embedded shortwave trough crosses the region. Thunderstorm
potential today will again be minimized by a relative lack of
surface based instability, but can`t rule out a rumble or two of
thunder in any over-performing cells this afternoon. Model QPF
values remain rather meager, with most locations maxing out
around a tenth of an inch through this evening, perhaps with a
few spots in the higher terrain getting closer to a quarter
inch. Minor snow accumulations will remain possible through the
Cascade passes as snow levels continue to reside around
2500-3000 ft. Shower activity will taper off tonight in the
wake of the shortwave as drier northerly flow begins to filter
into the region. Partial clearing will help temperatures drop
into the 30s in the interior valleys tonight. Current thinking
is that fog will be more prevalent than frost tonight given
recent rainfall and enhanced low level moisture. Thursday looks
to be a dry and pleasant spring day with temperatures close to
seasonal norms in the upper 50s across the lowlands. Expect
another chilly night Thursday night into Friday morning, with
frost becoming the more prevalent concern as northerly flow
continues to dry out the low levels of the atmosphere. Will
continue to monitor the eventual need for Frost Advisories for
Friday morning, with the most likely locations being the south
and central Willamette Valley as well as outlying colder areas
of the Portland/Vancouver metro such as Hillsboro and
Battleground.

Models and their ensembles continue to show excellent agreement
in warmer temperatures for Friday and Saturday as an upper level
ridge builds over the region. Expect temperatures to climb well
into the 60s on Friday afternoon, with the NBM depicting a
50-60% chance to reach 70 degrees in the Portland/Vancouver
metro and closer to a 20% chance in the rest of the Willamette
Valley. Saturday will likely be the warmest day of the week as
NBM probs to reach 70 increase above 80-90% in most inland
locations. Forecast confidence decreases on Sunday as models
continue to struggle with timing the breakdown of the ridge and
subsequent arrival of the next upper level trough. The
uncertainty is reflected across the GEFS and ECENS which both
have some members depicting rainfall arriving as early as Sunday
morning while others hold off until Sunday night. NBM maintains
a rather large spread of temperature outcomes as result, with
highs remaining in the mid to upper 70s in the case of the
slower solution but also possibly topping out in the mid 60s if
the faster solution comes to fruition. Forecast confidence
actually increases for Monday as models are in good agreement
that the ridge will have shifted east of the region by early
next week, with precipitation chances increasing and
temperatures returning closer to seasonal norms through
Tuesday. /CB

&&

.AVIATION...Radar, satellite and surface observations show mostly
generally VFR conditions with scattered showers moving into the
airspace from the northwest, as an upper level shortwave trough
moves through the area. This will result in predominately VFR
conditions with FL030 to FL050 expected throughout the day.
Showers will move from the NW to the SE and could result in brief
periods of MVFR conditions (30% probability) through 00Z
Thursday. Afterwards, conditions will gradually dry up and result
in widespread VFR as an upper level ridge moves over the airspace.
Expect westerly to northwesterly winds across all terminals
around 5-10 kt today.

KAST anemometer is still inoperative. Therefore, TAFs limited to
CIG and VIS.

PDX AND APPROACHES...Predominately VFR conditions with scattered
showers through 00Z Thursday. Any showers could result in brief
periods of MVFR conditions (30% probability) through 00Z
Thursday. Afterwards, widespread VFR. Westerly winds become more
northwesterly, generally less than 10 kt. /42

&&

.MARINE...High pressure over the northeast Pacific and lower
pressure inland will maintain northerly to northwesterly winds
under 15 kt through the end of the week. Seas 5-7 ft at 9 seconds
today will gradually decrease to 3-4 ft by Thursday. The next
front arrives Saturday evening into Sunday, returning breezy
southerly winds. As the front approaches the waters, there is a
20-30% chance for Gale-force southerly wind gusts up to 35 kt
on Sunday. At the same time, seas will likely (greater than 90%
chance) build to 10-12 ft as a westerly swell pushes into the
waters.

Another strong ebb is expected Thursday morning; however, seas
with this ebb are forecast lower around 4-5 ft so decided not to
issue another Small Craft Advisory for this ebb. -Alviz

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

www.weather.gov/portland

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