Welches, Oregon Weather Forecast Discussion

617
FXUS66 KPQR 191835
AFDPQR
Area Forecast Discussion
National Weather Service Portland OR
1133 AM PDT Fri Sep 19 2025
.SYNOPSIS...
Onshore flow will persist through the weekend and into early
next week, maintaining seasonable conditions. A deeper trough
moving in from the Gulf of Alaska will bring a cool-down and
increasing rain chances late in the weekend. The most impactful
system arrives Sunday with widespread precipitation, including a
period of elevated chance of wetting rain (CWR), and there
remains a low potential for isolated thunderstorms in the
Lane/Linn County Cascades on Friday and a bit more widespread on
Sunday. A weaker, less certain system could bring additional
precipitation midweek.
&&
.SHORT TERM...Now through Saturday...Tranquil weather will
dominate most of the area during the short term period. High
pressure offshore will maintain mostly clear skies through
today, though some clouds may drift into eastern Lane/Linn
Counties tonight as a weak surface low over northern California
shifts northward. Overnight lows will be near average, in the
upper 40s along the coast and lower 50s inland.
Temperatures today will rise into the 80s inland, with only a
10-20% chance of exceeding 85 degrees. Coastal highs remain in
the 60s. A narrow 5-10% chance of a shower or isolated
thunderstorm remains over the Lane/Linn County Cascades Friday
afternoon and evening, but the rest of the area is expected to
remain dry. Saturday will see slightly cooler conditions, but
highs should still reach the low 80s inland and 60s along the
coast. Winds will shift westerly and eventually southwesterly
late Saturday night as a strong front approaches the coast.
.LONG TERM...Saturday Night through Thursday...Rain chances
increase late Saturday into Sunday as a strong shortwave trough
digs southeast from the Gulf of Alaska. The associated cold
front is expected to reach the coast around midnight Saturday
night, then progress inland near daybreak Sunday (~5 AM). that
said, confidence in exact timing remains low at this time.
Probabilities for precipitation increase to around 40% across
much of northwest Oregon and southwest Washington, with
localized values up to 80% as the front moves through.
Chance of wetting rain (CWR) rises to 30-60% through Sunday
during the frontal passage, mainly along the coast and across
southwest Washington. A low-end chance (~10%) for isolated
convection lingers into Sunday morning across southwest
Washington and northwest Oregon. Temperatures Sunday will cool
noticeably under cloud cover and frontal passage, generally
topping out in the low 70s inland and 60s along the coast.
Early next week, temperatures moderate back to seasonable levels
with inland highs in the mid to upper 70s and 60s along the
coast. There is a 20-40% chance for inland highs to reach 85
again on Tuesday. Precipitation potential has shifted later in
the period, with only 20-40% of ensemble clusters now suggesting
measurable precipitation by midweek. For now, a 10-20% chance of
showers is maintained from Wednesday through at least Thursday,
though details remain uncertain.
~Hall
&&
.AVIATION...High pressure aloft and low level northwesterly to
westerly winds will bring predominantly VFR conditions through
18z Saturday for inland terminals and extended periods of IFR to
LIFR conditions along the coast. The main exception to that
statement along the coast will be fog and low clouds along the
coast should push back to just offshore for most, if not all, of
the afternoon and result in a several stretch of VFR conditions
before the fog and low clouds surge back into the coastal TAF
sites between 00-03z Saturday. The marine layer appears likely to
deepen overnight, which should allow marine clouds and fog to push
farther into the Coast Range gaps overnight, but the probability
that IFR conditions reach KEUG from the southwest is 20% and KPDX
from the northwest is less than 10%.
KPDX AND APPROACHES...High pressure aloft and low level
northwesterly winds will bring predominantly VFR conditions
through 18z Saturday. There is a less than 10% chance for high
end IFR conditions briefly impacting the terminal around 15z
Saturday.
&&
.MARINE...Northerly winds will gradually ease today with gusts
generally remaining below 20 kt. Dense fog has developed across
the inner waters this morning. This may temporarily dissipate
midday before consolidating again late this afternoon and evening
so additional dense fog advisories appear likely.
Seas are currently around 6 to 7 ft at 9-10 seconds where seas
should remain through Saturday. The next frontal system arrives
this weekend from the northwest with winds turning southerly
beginning Saturday afternoon across the waters. There is a 70-80%
chance that winds increase into Small Craft Advisory thresholds
with gusts of 25 kt Saturday night across at least the northern
waters. The strongest winds appear most likely to occur within 10
NM of the north Oregon and south Washington coast as a weak
coastal jet develops. There is a 80% chance that seas climb into
the 8-11 ft range by the end of Sunday night as a fresh swell
moves into the water.
High pressure then returns to the northeast Pacific. This will
result in northerly winds returning to the waters on Monday. A
weakening front then approaches the waters midweek.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Dense Fog Advisory until 1 PM PDT this afternoon for PZZ210-
     251>253.
Small Craft Advisory until 11 AM PDT this morning for
    PZZ272-273.
&&
$$
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NWS PQR Office Area Forecast Discussion