or discuss
Office: MFR
FXUS66 KMFR 010538
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
938 PM PST Sun Nov 30 2025
.Updated AVIATION and MARINE Discussions...
&&
.AVIATION...01/06z TAFs...Aside from persistent MVFR stratus in the
Umpqua Basin, and patchy LIFR in the Grants Pass area, VFR
conditions prevail across the region with high level cirrus
streaming overhead. Offshore flow across the area should keep fog
development limited along the coast and east of the Cascades/Klamath
Basin, so VFR conditions are expected to prevail through the TAF
period there. There could be a few hours overnight for some
scattered LIFR conditions at North Bend/Coquille Basin, but easterly
flow should keep this from persisting.
For the Rogue/Illinois/Applegate Valleys and the Umpqua Basin,
IFR/LIFR conditions are likely tonight into Monday morning, then
clear to VFR by 18-21z. High level cloud cover is expected to
continue overnight and this could limit the extent of the fog
development and persistence. VFR conditions are expected to prevail
across northern California through the TAF period. /BR-y
&&
.MARINE...Updated 800 PM PST Sunday, November 30, 2025...Northerly
winds will increase this evening, with gusts south of Port Orford
reaching Small Craft Advisory strength. The strongest north winds
will shift to the outer waters south of Cape Blanco tonight, with
steep seas expected to persist over the southern waters at least
into Wednesday. Seas may also become steep north of Cape Blanco on
Tuesday. An incoming long period west swell is expected to peak at 7
to 11 ft Monday into Tuesday with a period around 21 seconds.
Conditions may briefly improve for Thursday, but the pattern is
likely to turn more active late in the week.
&&
.PREV DISCUSSION... /Issued 343 PM PST Sun Nov 30 2025/
DISCUSSION...High pressure over the Pacific Ocean has built a
resilient ridge, with the front edge remaining over the area. With
this pattern, seasonal temperatures and mild weather looks to
continue through most of the week. Northerly or northwesterly flow
will keep midlevel or high level clouds moving through the sky
during the day. Drier air over the area tonight looks to bring
cooler temperatures into early Monday morning, and
An "inside slider" (shortwave troughs that travel down the ridge and
to the southeast into a deeper continental trough) may interrupt the
general pattern early in the week. The first slider approaches on
Monday, raising overnight lows into early Tuesday morning. Some
slight chances for rainfall (25-50%) are present along the coast and
northern Douglas County during the day Tuesday. Any rain that does
fall in these areas will likely be measured in the hundreths of an
inch. Overnight lows will drop across the area Tuesday night into
early Wednesday, and areas along and east of the Cascades will see
cooler daytime highs on Wednesday. A significantly weaker shortwave
trough is in the upper pattern late Wednesday, with some imagery
showing the trough traveling farther east. Unless this trough
deepens and shifts west, it looks to have little to no impact.
The NBM shows signs of precipitation along the coast and Cascades as
early as Thursday afternoon, but this may be optimistic by a day.
Deterministic imagery for the ECMWF and GFS models show a cold front
managing to flatten the Pacific ridge enough to bring some showers
west of and along the Cascades late Friday into Saturday. There's
some divergence beyond, with the ECMWF drying out by Sunday and the
GFS staying active through the weekend and into next week.
Meteograms for both models generally support their respective
deterministic patterns, although the ECMWF ensemble has ~20% of its
members showing continuing rainfall. If the GFS outcome holds true,
precipitation amounts and snow levels will be a focus of future
forecasts. -TAD
BEACH HAZARDS/HIGH SURF...Updated 100 PM PST Sunday, November 30,
2025...Guidance shows a long period swell arriving Monday, first
arriving at around 3 to 5 ft at 21 to 22 seconds early Monday
morning. This swell is expected to peak at around 7 to 11 ft at 16
to 18 seconds Monday afternoon into Tuesday morning. While seas
will be steep, high surf conditions are not expected along
beaches. If you have plans to visit the coast on Monday, please be
aware of this sneaker wave potential and consider rescheduling
your ventures to the beaches for another day. These waves can wash
over rocks and jetties and can suddenly knock people off of their
feet and sweep them into the ocean. They can also move logs or
other objects which could crush or trap anyone caught underneath.
While sneaker waves can occur at any time, the greatest risk is on
an incoming tide. Please be aware of the tides if venturing out
onto the beaches. Remember, NEVER turn your back on the ocean!
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Beach Hazards Statement from 7 AM PST Monday through Tuesday
afternoon for ORZ021-022.
CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM Monday to 7
AM PST Wednesday for PZZ356.
Small Craft Advisory until 7 AM PST Wednesday for PZZ376.
&&
$$
Office: PQR
FXUS66 KPQR 010534 AAA
AFDPQR
Area Forecast Discussion...UPDATED
National Weather Service Portland OR
934 PM PST Sun Nov 30 2025
Updated aviation discussion.
.SYNOPSIS...High pressure continues over the region today with
mostly dry conditions expected through Monday. Chilly
temperatures expected Monday morning. A weak front will bring
chances for light rain Monday night into Tuesday. Dry again on
Wednesday. Active weather returns as a series of frontal systems
bring increasing chances for rain later Thursday through the
weekend. Seasonable temperatures continue through the week.
&&
.SHORT TERM...Now through Tuesday Night...High pressure over the
area will keep today and Monday dry and generally clear with
cool overnight temperatures. While there have been a few
fluctuations in the forecast overnight lows, the overall impacts
will see little change. Continue to see high probabilities for
widespread frost in the lower elevations. Frost probabilities
are lowest within the Cascade valleys, the greater Portland-
Vancouver Metro, and exposed areas to higher winds. Elsewhere
(aside from the coast), there is greater than a 50% chance of
frost. In some rural areas it may be impactful enough to damage
any lingering vegetation. Those cooler temperatures will be
short lived though as a warm front moves over the area late
Monday into Tuesday. This front will bring rain to much of the
area but the main focus will be to the north and along the
terrain. 24 hour precipitation totals ending at 10 PM Tuesday
have lower end amounts of anywhere from 0.01-0.04" along the
coast with nearly nothing inland. higher end amounts though
range from 0.2-0.3" along the coast and up to 0.1" inland. In
southwest Washington though there is a 10% chance of 0.25" of
rain. Snow levels remain elevated so there is no risk for snow
in the lower elevations. -27
.LONG TERM...Wednesday through Sunday...Ensembles are consistent
in a high pressure ridge rebuilding on Wednesday. This ridge
will aid in pushing the front eastward and keep conditions
fairly "boring" through Thursday. Based on the global ensembles
there is around a 10% of some light continued precipitation
through the day on Wednesday but precipitation doesn't start
ramping up until Thursday morning. This precipitation is
expected to be light through the day but picking up overnight.
On Friday there is a trend towards yet another warm frontal
system. This front is associated with a low pressure system over
the Alaska Panhandle. Stratiform rain will fall with the GFS
being the more robust system. With atmospheric warming this time
of year there is generally a concern for Atmospheric River (AR)
conditions. Based on the IVT values of both the GFS and ECMWF
there is a trend to a low to moderate AR that will persist
from the 4th through the 6th. When looking at the track,
vectors are pointing straight easterly which would bode well for
periods of heavy rain. Given the long duration, will have to
consider watching for any flooding impacts. The GFS continues to
be the most rain heavy scenario with around a 5% chance of
2-2.5" in 24 hours ending Saturday morning around Astoria, and
less than a 5% chance of greater than 1.25" around Salem.
Rain persists through Sunday. I will note that some models are
suggesting around a 10% chance of flooding after Sunday.
However, these values are likely being triggered by the GFS that
is running much higher than it's other global ensemble
counterparts. -27
&&
.AVIATION...High pressure building offshore will maintain VFR
conditions through 06z Tuesday. Light and variable winds are
expected for all inland terminals through 06z Tuesday, except at
KTTD and KONP where east winds around 8-13 kt will continue
through approximately 18z Monday, strongest at KTTD. Not
expecting fog to develop tonight as the airmass in place is
relatively dry, favoring frost development instead of fog as
temperatures dip into the low to mid 30s.
Towards 05-06z Tuesday, probabilities for MVFR cigs around 3000 ft
increase to near 30% at KAST. Light rain showers are likely to
develop at KAST shortly after 06z Tuesday.
KPDX AND APPROACHES...VFR conditions expected through the period
with beneath scattered high clouds. Light and variable winds
around 5 kt or less are expected to continue through 06z Tuesday.
&&
.MARINE...Benign weather continues across the coastal waters with
weak offshore flow at 5-10 kt and seas of 5-8 ft. Building high
pressure offshore will see flow turn increasingly out of the north
through Monday night while seas remain around 5 ft. A weak front
traversing the waters Monday night into Tuesday will see northwest
winds increase to 15-20 kt while a long-period westerly swell will
build seas to 9-11 ft on Tuesday. Winds and seas then ease midweek
before a more active weather pattern develops late in the week. At
this point, there are 25-40% chances seas rise above 10 ft again
Friday into next weekend, but this potential hinges on the track
and intensity of any potential weather system. -36
&&
.BEACH HAZARDS...A long-period westerly swell is expected along
the northwestern Oregon and southwestern Washington coasts from
late Monday through Wednesday next week. Wave heights increasing
to 8 to 10 ft on Tuesday may not appear to present a safety risk
to those on area beaches, but these energetic waves will present a
moderate to high risk for sneaker waves, waves which can run
significantly farther up a beach than normal, including over rocks
and jetties. In addition, a period of perigean spring or "king"
tides means these waves will have an even easier time reaching
high up onto beaches, limiting the areas which may be safe from
wave action.
A Beach Hazards Statement has therefore been issued from 7 AM
Tuesday to 10 PM Wednesday. Sneaker waves can create potentially
life-threatening conditions in the surf zone when beachgoers can
be unexpectedly knocked off their feet and pulled out into cold
ocean waters. Caution should be used when in or near the water,
and those with children should be especially watchful. Never turn
your back on the ocean, and be sure to keep an eye on the waves.
Those participating in razor clam digs should additionally
exercise caution. -36
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.
&&
$$
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Office: PDT
FXUS66 KPDT 010546
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
946 PM PST Sun Nov 30 2025
.Updated Aviation Discussion.
.AVIATION...06Z TAFS...VFR conditions currently observed across all
sites, which will stay the course through the period. There is a
slight chance (10-20%) for fog development overnight, with best
chances at KYKM/KALW/KDLS, but confidence is low enough to not
include in forecast. Ceilings will decrease to between 4-6kft
Monday afternoon in response to an approaching system. Winds will
stay light and below 10kts for all terminals through Monday
evening. 75
&&
.PREV DISCUSSION... /issued 219 PM PST Sun Nov 30 2025/
KEY POINTS...
1. Cold overnight temperatures with patchy fog/freezing fog
2. Mountain snow returns Monday morning into Tuesday afternoon
3. Widespread rain and high mountain snow Thursday night through the
weekend
DISCUSSION...Current satellite shows portions of the region to be
clearing out with only high clouds lingering overhead. However, the
eastern mountains through the Northern Blues still have a stratus
deck overhead. The round of snow from last night averaged 1 in here
at the office with other areas reporting a skiff to 0.5 inches of
snow on the ground. Dry northerly flow has taken over today and will
continue to usher in dry and cold temperatures through Monday
morning.
Today through Wednesday...Northerly flow will keep the region under
cold and dry conditions. Low clouds have persisted over the eastern
mountains and the Blues today mainly due to upslope flow. Cold air
will continue to settle over the region through the overnight hours
which will lead to patchy to areas of fog/freezing fog overnight
into the morning through many of the valleys, basins and foothills of
the Blues as well as areas along the Columbia River. Temperatures
overnight will be below freezing across the entire region with all
locations, except through the Gorge and isolated spots along the
river, seeing temperatures below 32 degrees with well over 80%
probabilities.
Monday afternoon and into the evening, models show a shortwave ahead
of a weak trough beginning to make its way towards the region. The
shortwave will bring back snow showers to the WA Cascades and across
the eastern mountains and the Northern Blues. 24 hour Raw guidance
has 50-80% probabilities of 1-3 inches across the Northern Blues,
Eagle Caps and higher elevations of the WA Cascades Monday night
though Tuesday. Zooming in on the I-84 corridor, raw ensembles show
50-70% probabilities of near 2 inches of snow and along the I-90
corridor 30-50% probabilities of 0.5-1 inch of snow.
Models show by Tuesday night the shortwave will have mostly cleared
the region allowing northerly dry flow to dominate the region again.
Dry and cold temperatures will dominate the region Wednesday ahead of
the next incoming wave. Temperatures again will be below 32 degrees
for much of the region with only the Gorge and isolated areas along
the river seeing temperature at or slightly above freezing with 75-
95% probabilities.
Thursday onwards...Models show another round of shortwaves making
their way into the region beginning Thursday that will another round
of mountain snow spreading to widespread rain across the lower
elevations. Clusters do shift in phase a bit with the biggest
discrepancy being in the timing of the event as well as amounts of
precipitation expected. Models do show the heaviest amounts of
precipitation will occur Thursday before slowly tapering off over
the weekend. Snow levels will be over 4000 ft and increasing to
above 6000 ft before decreasing to below 4000 ft Sunday. High
elevation snow is expected, however, along the I-90 and I-84
corridors little to no fall is expected with this system with
moderate confidence (60-70%). Much of the precipitation will fall as
rain below 4000 ft with only slight chances (15-30%) through
central/north central OR, the lower Columbia Basin of OR & WA and 30-
50% chances of 0.01-0.04 along the foothills. Highest amounts will
be through the mid to upper elevations Friday. Saturday,
precipitation looks to spill over along the eastern slopes of the
Cascades and farther along the foothills with (50-70%) probabilities
of those areas seeing between 0.01-0.05 inches of rain. Sunday will
see dryer conditions across the lower elevations with only light
rain across the eastern mountains with continued snow showers along
the higher crests. All in all a moderate chance (60-70%) of having a
wet weekend. 90
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 22 38 30 40 / 0 10 40 60
ALW 26 37 31 38 / 0 20 50 70
PSC 25 37 27 39 / 0 10 20 20
YKM 24 38 25 43 / 10 10 10 0
HRI 25 37 28 41 / 0 10 30 40
ELN 22 37 25 43 / 10 20 20 10
RDM 19 49 27 46 / 0 10 10 10
LGD 21 42 31 40 / 0 10 40 80
GCD 21 47 31 43 / 0 10 30 50
DLS 31 42 35 50 / 10 20 20 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
DISCUSSION...90
AVIATION...75
