Humbug Ridge Trail Oregon Weather Forecast Discussion

065
FXUS66 KPQR 111848
AFDPQR
Area Forecast Discussion
National Weather Service Portland OR
1130 AM PDT Sat Oct 11 2025
.SYNOPSIS...A broad upper-level trough and embedded coastal low
continues to drive cool and unsettled weather across the
Pacific Northwest through the weekend. Expect periodic rain,
mountain snow, and below-normal temperatures. Conditions
gradually moderate midweek as a ridge builds over the region,
though model uncertainty grows toward late week.
&&
.DISCUSSION...Now through Friday...Satellite and radar imagery
early this morning depict a compact upper-level low now centered
near the Oregon coast, with widespread cloud cover and
intermittent light to moderate rain inland. As of 4 AM,
overnight temperatures have dipped into the low 50s to upper 40s
across the interior valleys, and a Frost Advisory remains in
effect for Hood River County until 8 AM this morning.
Uncertainty persists regarding additional frost or freeze
headlines over the next few nights. For Saturday night into
Sunday, frost formation hinges on whether clouds sufficiently
clear - confidence remains low to moderate. The Sunday night
into Monday period could see near-freezing conditions as cold
air lingers, though thicker cloud cover may limit frost
formation. Monday night into Tuesday currently appears to hold
the highest potential for a Freezing Warning, given cloud cover
is forecasted to clear through Monday.
As the coastal low drifts slowly inland today, expect another
period of widespread rain, tapering to showers by late afternoon
and evening. Rainfall totals through today are forecast to range
from 0.10-0.20 inches in the interior valleys to 0.20-0.40 inches
along the coast, Coast Range, and Cascades. Probabilities for
24 hour accumulation exceeding 0.50 inches sit around 15-30% for
the Willamette Valley and 40-80% for the coast, Coast Range,
and Cascades.
The upper low begins to move eastward late tonight into Sunday,
allowing for a transition to more showery and convective
precipitation. Model soundings and ensemble guidance suggest
around a 15% chance for isolated thunderstorms through much of
Sunday, primarily along the coast but still possible inland. By
Sunday night, a colder post-frontal air mass settles into the
region. Highs Sunday and Monday will remain in the mid 50s to
low 60s for most lowland areas and upper 30s to upper 40s
across higher terrain. Snow levels lower to around 3500-5000
ft, bringing the potential for 2 to 5 inches of wet snow near
pass level, with up to 6 to 12 inches at higher elevations above
5000 ft.
For Saturday through Monday, ensemble 72 hour total
precipitation probabilities indicate a 50-75% chance for 1 inch
or more across the interior lowlands and 75-95% for coastal and
mountainous areas. For 1.50 inches, probabilities drop to 20-40%
for the valleys and 50-80% for higher terrain.
Tuesday into Wednesday, a transition toward higher pressure and
drier weather is expected as ensemble cluster guidance favors a
ridge building over the northeast Pacific. This will bring
moderating temperatures, highs climbing into the 60s and PoPs
dropping to 10-20%. Uncertainty increases toward Thursday and
Friday. Several ensemble members rebuild the offshore low and
push it back toward the coast. If that scenario materializes,
weak onshore flow and increasing cloud cover could return,
bringing PoPs back up into the 30-50% range. Confidence in this
late week pattern remains low as ensemble spread continues to
widen regarding the strength and placement of the reemerging
trough.
~12
&&
.AVIATION...An upper level low pressure system will continue to
produce periods of showers and predominantly VFR conditions with
occasional dips into MVFR thresholds at most terminals through at
least 03z Sunday. A mix of VFR and MVFR conditions will continue
along the coast between 06-18z Sunday. However, high resolution
model guidance suggests that inland locations will see an extended
period of VFR conditions overnight before the next round of showers
arrive and produce 30-40% chance of MVFR ceilings occurring at any
given hour at inland TAF sites between 12-18z Sunday.
KPDX AND APPROACHES...An upper level low pressure system will
continue to produce periods of showers and predominantly VFR
conditions with occasional dips into MVFR thresholds. The
probability for MVFR ceilings occurring at any given hour will be
around 30% through about 03z Sunday before dropping below 10%
overnight and before then climbing to 30-40% between 12-18z Sunday.
&&
.MARINE...A weak low pressure system shifting inland will result
in northwesterly winds building across the waters this afternoon and
evening. There is a 25% chance that gusts briefly peak around 35 kt
beyond 40 NM across the northern waters, but given the brevity and
low confidence of occurrence will keep Small Craft Advisory in
place. There is an 80% chance that seas build into the 9-14 ft range
across the waters this evening into early Sunday.
The highest seas will be across the northern outer waters while the
lowest seas will be across the southern inner waters off the central
coast of Oregon.
A weak low pressure will then drop southward across the waters late
Sunday into Monday. This will usher in a reinforcing shot of gusty
northerly winds during this period. Seas will remain elevated as a
result. High pressure then looks to build back across the northern
Pacific during the middle of next week. This looks to allow seas to
drop down to around 5 ft.
There remains quite a bit of uncertainty surrounding the weather
pattern next week.  end of next week has a fair amount of
uncertainty as guidance suggests an 80% chance that significant wave
heights will be between 6 and 13 ft across the waters on
Friday/Saturday.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Frost Advisory until 8 AM PDT this morning for ORZ121.
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 11 PM PDT this
     evening for PZZ210.
Small Craft Advisory from 3 PM this afternoon to 11 PM PDT this
     evening for PZZ251>253-272-273.
Hazardous Seas Watch from this evening through Sunday afternoon
     for PZZ251>253-272-273.
Small Craft Advisory from noon today to 5 PM PDT this afternoon
     for PZZ271.
Hazardous Seas Watch from this afternoon through Sunday
     afternoon for PZZ271.
&&
$$
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NWS PQR Office Area Forecast Discussion