or discuss
Office: MFR
FXUS66 KMFR 012347
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
347 PM PST Mon Dec 1 2025
.Updated AVIATION Discussion...
&&
.AVIATION...02/00z TAFs...VFR conditions prevail across the region
this afternoon with a thick layer of high level cirrus streaming
west to east over the area. This should keep fog from developing
until this cirrus moves south of the area, which is expected around
06z-10z. There should be a long enough period of clear skies for
LIFR/IFR conditions in fog/low clouds to develop in West Side
Valleys before another shortwave passes through the region early
Tuesday morning. This includes areas along the coast north of Cape
Blanco if wind direction shifts far enough southeast to bring any
low clouds from the Coquille Basin to impact North Bend. This
shortwave should limit at least the duration of fog, bringing
improving conditions to VFR by for all areas by 18z Tuesday, if not
earlier. /BR-y
&&
.PREV DISCUSSION... /Issued 224 PM PST Mon Dec 1 2025/
DISCUSSION (Today through Sunday)...
Key Points:
* We continue to see overall minimal impacts through this week
* By far and large, mostly dry conditions expected through Fri
* Next reasonable chance for precipitation is Saturday
- Could be as early as Friday night
- Snowfall for elevations mainly above 5,000 ft
* Morning fog may be a common theme this week for westside valleys
Further Details:
The upper levels (500mb) can be summed up--with one caveat--as a
ridge aloft through Friday. The caveat here is the ridge does shift
westward enough on Tuesday to allow meridional flow to bring a very
progress area of PVA through the region. The moisture is lacking in
this scenario, and the main impact here may be the colder airmass
advecting in from Canada. Outside of very isolated light rainfall,
most areas will likely be dry. Tuesday night (Wed morning) is in
fact the coldest time period in the forecast and fog (or freezing
fog) may come to fruition which could lead to ice accumulation on
elevated surfaces Wednesday morning. Tomorrow morning may be another
candidate for light icing on elevated surfaces, but temperatures may
be borderline Tuesday morning (i.e. less confidence compared to Wed
morning).
Overall, deterministic and ensemble guidance are in fairly good
agreement with the general pattern this week. We do start to see
some minor discrepancies Friday as models bring in the system where
we could see widespread precipitation chances on Saturday. At this
point, the impacts look to be minimal in any solution with rainfall
expected for most areas, but some elevations above 5K feet could see
snowfall amounts around 2-5 inches. In typical fashion, coastal
areas will see the highest QPF amounts, but the Umpqua Basin and the
Cascades will also be on this list of higher QPF amounts. At this
time, flooding appears unlikely, but nuisance type flooding with
ponding on roadways will be possible. Additionally, there may be
isolated flood prone areas that have poor drainage that could see
further nuisance type flooding. That being said, not seeing any
notable river rises with this system, and we are not expecting
widespread flooding.
-Guerrero
MARINE...Updated 215 PM PST Monday, December 1, 2025...Breezy to
gusty northerly winds will continue through Wednesday, with gusts
south of Port Orford reaching Small Craft Advisory strength.
Additionally, long period west swell will build into the waters
late today and tonight, then peak on Tuesday (with west swell
building to 8 to 9 feet at 16 seconds and combined seas of 9 to 11
feet). Steep seas are expected across the waters south of Cape
Blanco through at least Wednesday, and some areas south of Gold
Beach may see Hazardous Seas Tuesday into Tuesday night. Seas may
also become steep north of Cape Blanco Tuesday night and
Wednesday. Conditions may briefly improve for Thursday, but the
pattern is likely to turn more active late in the week.
BEACH HAZARDS/HIGH SURF...Updated 215 PM PST Monday, December 1,
2025...A long period swell is expected to build to around 7 to 9
ft at 16 to 18 seconds late this afternoon into Tuesday morning
with combined seas of 9 to 11 feet. While seas will be steep, high
surf conditions are not expected along beaches. However, these
conditions will bring a risk for dangerous sneaker waves. If you
have plans to visit the coast today, 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 through Tuesday afternoon for ORZ021-
022.
CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory until 4 PM PST
Wednesday for PZZ356-376.
&&
$$
Office: PQR
FXUS66 KPQR 020023
AFDPQR
Area Forecast Discussion
National Weather Service Portland OR
345 PM PST Mon Dec 1 2025
.SYNOPSIS...A series of fronts will bring a wet period of
weather later this week into the weekend across southwest
Washington and northwest Oregon with potentially more impactful
rain next week.
&&
.DISCUSSION...Waver vapor satellite imagery this afternoon
reveals a shortwave ridge of high pressure over the eastern
Pacific. A shortwave trough is dropping southeastward towards
the Pacific Northwest. A mid level front is generating a band of
rain moving southeastward across northwest Washington this
afternoon and could bring a few sprinkles to the northern
portions of the CWA later this evening. Meanwhile, the low
level front is just beginning to push into the Olympic Peninsula.
REFS guidance is in general agreement it will move onto the
south Washington and north Oregon coast late this evening
to around midnight before pushing into the Willamette Valley
late tonight into early Tuesday morning while simultaneously
falling apart. The net result will be a cloudy and in spots
drizzly Tuesday. Light north to northeasterly flow spreads
across the region late Tuesday afternoon into Tuesday night.
This may result in just enough clearing to allow fog and low
clouds to redevelop overnight across inland valleys. The flow
will turn more northwesterly Wednesday and open us to weak
shortwave troughs that could bring light precipitation to mainly
our far northern zones and terrain late Wednesday into early
Thursday.
Models and their ensembles are in good agreement that the upper
level ridge remains over the northeast Pacific on Thursday. WPC
cluster analysis does indicate there is a high probability of
the ridge flattening out, allowing for more westerly flow into
the Pacific NW Friday and into the weekend. This should allow
for frontal systems and attendant atmospheric rivers to bring
increased rainfall and more active weather to the area.
Ensembles are in relatively good agreement, a moderate strength
atmospheric river will spread into the region Friday into early
Saturday bringing with it mainly beneficial rains to the region.
The EC EFI does suggest some notable rainfall amounts will
occur across the Oregon Cascades and foothills Friday night
into Saturday relative to model climatology, but raw ensemble
rainfall amounts appear unlikely to produce impacts with this
first round of rain. With that said, there are handful of the 100
global ensemble members that produce enough rain that our flashiest
rivers would rise sharply and approach minor flood stage Friday
into Saturday, but at this point, confidence remains low in
this scenario panning out based on available ensemble guidance.
Additional rounds of rain will continue for the remainder of
the weekend as ensembles are in general agreement we will remain
under zonal flow in the vicinity of the baroclinic zone. Given
the westerly flow there will likely be periods where the
Willamette Valley rain-shadows out, but it may be raining, at
least lightly, for a significant portion of the weekend across
the terrain, particularly areas farther north in the CWA.
Uncertainty in the forecast details grow significantly early
next week and mainly revolve around whether or not a stronger
atmospheric river with potential impacts to area rivers will
impact the region or not. HEFS guidance does suggest a ~10-15%
chance for rivers like the Willapa, Naselle and Wilson Rivers
to reach minor flood stage at some point in the next 10 days
with that day 8-10 timeframe being the main driver of those
probabilities.
&&
.AVIATION...Statistical model guidance suggests there is a
20% chance that IFR to MVFR restrictions return to KEUG later
this evening as low stratus tries to redevelop, but given low
clouds hung on the nearby Coburg Hills, suspect it's more likely
to happen. A weak front will drop southeastward across
southwest Washington and northwest Oregon overnight. Little in
the way of wind will accompany this front. This will result in a
several hour window where ceilings will have the potential to
lower into IFR and MVFR thresholds as the lower atmosphere
saturates along the coast between 06-12z Tuesday and between
12-18z Tuesday for inland taf sites. Our best statistical model
guidance suggests a 30-50% chance (highest for KAST and lowest
farther south towards KONP) for MVFR restrictions developing at
any given hour in the 06-12z Tuesday timeframe. Probabilities
are more in the 30-40% range for MVFR conditions to develop at
any given hour in the Willamette Valley, primarily in the 12-18z
Tuesday timeframe. The highest chances for IFR conditions will
be at KAST in the 06-12z Tuesday timeframe and climb into the
20-30% range at KEUG and KHIO in the 12-18z Tuesday timeframe
and remain around 10% at other sites like KPDX and KSLE.
KPDX AND APPROACHES...VFR conditions will give way to lowering
ceilings as a weak front slides across the terminal late
tonight into early Tuesday morning. Probabilities for MVFR
ceilings start climbing between 09-12z Tuesday as the front
approaches the region and then peak around 30-40% at any given
hour between 12-18z Tuesday as the front crosses the region. The
probability of IFR conditions developing at any given hour
peaks around 10% between 15-18z Tuesday. The end result is that
conditions will turn a little soupy with flight restrictions
more likely than not, but the main uncertainty revolves around
when exactly these conditions will begin and how long they will
last into Tuesday.
&&
.MARINE...Light northeast winds around 10 kt will turn
northwesterly as a frontal boundary approaches from the
northwest. This will increase winds across the waters, mainly
the outer zones north of Cape Foulweather where winds are
expected to reach low end Small Craft Advisory conditions. Winds
15-20 kt with gusts to 25 kt will be possible from 4 am to 10
pm on Tuesday. Elsewhere, winds will increase to 10-15 kt with
gusts to around 20 kt, staying below Small Craft criteria. A
long period, westerly swell is also expected to move into the
waters with heights increasing towards 10 feet at 15-18
seconds.
Winds and seas ease midweek as high pressure returns. A more
active weather pattern develops late in the week as a series of
frontal systems is expected to moves across the waters from
Thursday into the weekend. There is a 30-60% chance of seas
rising above 10 ft again Saturday into Sunday. /19
&&
.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...Small Craft Advisory from 4 AM to 10 PM PST Tuesday for PZZ271-
272.
&&
$$
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Office: PDT
FXUS66 KPDT 012231
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
231 PM PST Mon Dec 1 2025
.DISCUSSION...
Light snow is expected (40-90%) This evening through Tonight
across the Eastern Columbia Basin and foothills of the Blue
Mountains though the Northern Blues and Wallowas, creating winter
weather conditions. Lower elevations might only get a dusting or
more of snow but the snow amounts quickly ramp up with higher
elevations. A frontal system moving though This afternoon and
Tonight will be the initial strong orographic forcing impetus,
followed by persist northwesterly momentum behind the system
continuing to promote light precipitation in the dendritic growth
zone beyond 24 hours, driving high mountain areas well above 6
inches of snow with time. Latest HREF ensemble mean hourly trends
begin Northern Blue Mountains snow in earnest around 8z/or late
evening, with snow continuing through late afternoon Tuesday. For
Wallowa county – where 4 inches is the lower end for advisory,
snow chances for 4 inches or more below 5400 ft are quite low (20
percent or less across the majority of that area). The Northern
Blue Mountains of Oregon (OR502) have a higher minimum requirement
of 6 inches for advisories. In either case the probabilities for
this magnitude of snow is not meeting in 12 hours. One local
community with a greater risk of some snow imp- acts is Tollgate
where there is a 70% chance of 5 inches of total snowfall, and
about a 50% chance to hit or exceed the low end 6” threshold for
advisories.
Friday through the weekend look to be a windy period with
southwest winds increasing Friday evening, remaining windy
overnight and and not appreciably diminishing until Saturday
evening. Winds will pick up again diurnally Sunday, based on NBM
trends for this period. This change to a downslope windy regime
will lead to a more marked warmup on Friday where NBM is forcing
low to mid 50s across much of the Lower Columbia Basin, Blue
Mountain foothills, central Oregon and the John Day Basin.
&&
.PREV DISCUSSION... /issued 940 AM PST Mon Dec 1 2025/
AVIATION...18z TAFs...Low clouds and patchy fog continue for PSC
this morning, otherwise VFR conditions prevail across the forecast
area. Expect bkn-ovc cigs 7-10 kft throughout the day, with some
clearing early in the evening before the next frontal system
arrives by early morning Tuesday. IFR conditions may linger in PSC
over the next couple of hours, before seeing relief by the
afternoon. Not expecting precip with this next system across most
TAF sites, however PDT and ALW may see light rain showers
beginning at or just before sunrise, ending by the end of the TAF
period. Winds will generally be light and variable today, becoming
more W/NW overnight ahead of this next front. 74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 40 27 40 / 20 60 10 0
ALW 30 38 29 38 / 40 70 10 10
PSC 25 39 24 37 / 20 30 0 0
YKM 24 45 24 38 / 10 0 0 0
HRI 27 41 26 38 / 20 40 0 0
ELN 25 44 22 37 / 10 10 0 0
RDM 26 46 21 46 / 0 10 0 0
LGD 31 41 27 41 / 40 90 20 0
GCD 30 42 27 43 / 10 50 10 0
DLS 34 51 34 43 / 10 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...71
FXUS66 KPDT 012233 CCA
AFDPDT
Area Forecast Discussion...corrected
National Weather Service Pendleton OR
233 PM PST Mon Dec 1 2025
.DISCUSSION...
Light snow is expected (40-90%) This evening through Tonight
across the Eastern Columbia Basin and foothills of the Blue
Mountains though the Northern Blues and Wallowas, creating winter
weather conditions. Lower elevations might only get a dusting or
more of snow but the snow amounts quickly ramp up with higher
elevations. A frontal system moving though This afternoon and
Tonight will be the initial strong orographic forcing impetus,
followed by persist northwesterly momentum behind the system
continuing to promote light precipitation in the dendritic growth
zone beyond 24 hours, driving high mountain areas well above 6
inches of snow with time. Latest HREF ensemble mean hourly trends
begin Northern Blue Mountains snow in earnest around 8z/or late
evening, with snow continuing through late afternoon Tuesday. For
Wallowa county – where 4 inches is the lower end for advisory,
snow chances for 4 inches or more below 5400 ft are quite low (20
percent or less across the majority of that area). The Northern
Blue Mountains of Oregon (OR502) have a higher minimum requirement
of 6 inches for advisories. In either case the probabilities for
this magnitude of snow is not meeting in 12 hours. One local
community with a greater risk of some snow imp- acts is Tollgate
where there is a 70% chance of 5 inches of total snowfall, and
about a 50% chance to hit or exceed the low end 6” threshold for
advisories.
Friday through the weekend look to be a windy period with
southwest winds increasing Friday evening, remaining windy
overnight and and not appreciably diminishing until Saturday
evening. Winds will pick up again diurnally Sunday, based on NBM
trends for this period. This change to a downslope windy regime
will lead to a more marked warmup on Friday where NBM is forcing
low to mid 50s across much of the Lower Columbia Basin, Blue
Mountain foothills, central Oregon and the John Day Basin. Russell/71
&&
.PREV DISCUSSION... /issued 940 AM PST Mon Dec 1 2025/
AVIATION...18z TAFs...Low clouds and patchy fog continue for PSC
this morning, otherwise VFR conditions prevail across the forecast
area. Expect bkn-ovc cigs 7-10 kft throughout the day, with some
clearing early in the evening before the next frontal system
arrives by early morning Tuesday. IFR conditions may linger in PSC
over the next couple of hours, before seeing relief by the
afternoon. Not expecting precip with this next system across most
TAF sites, however PDT and ALW may see light rain showers
beginning at or just before sunrise, ending by the end of the TAF
period. Winds will generally be light and variable today, becoming
more W/NW overnight ahead of this next front. 74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 40 27 40 / 20 60 10 0
ALW 30 38 29 38 / 40 70 10 10
PSC 25 39 24 37 / 20 30 0 0
YKM 24 45 24 38 / 10 0 0 0
HRI 27 41 26 38 / 20 40 0 0
ELN 25 44 22 37 / 10 10 0 0
RDM 26 46 21 46 / 0 10 0 0
LGD 31 41 27 41 / 40 90 20 0
GCD 30 42 27 43 / 10 50 10 0
DLS 34 51 34 43 / 10 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
Discussion...71
AVIATION...99
FXUS66 KPDT 012239
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
239 PM PST Mon Dec 1 2025
Updated Aviation Discussion
.AVIATION...00z TAFs...VFR conditions expected through the period,
with the exception of PSC which continues to deal with low cigs this
afternoon, and PDT/ALW, which may see light rain showers early
Tuesday morning from an oncoming frontal system. Confidence in the
latter two sites seeing measurable precip is on the lower end
(30-40%), so opted to mention the chance of -ra via prob30.
Otherwise, skies will gradually clear across most sites this
evening, with winds generally less than 10 kts, becoming more W/NW
Tuesday as this oncoming front moves through. 74
&&
.PREV DISCUSSION... /issued 233 PM PST Mon Dec 1 2025/
DISCUSSION...
Light snow is expected (40-90%) This evening through Tonight
across the Eastern Columbia Basin and foothills of the Blue
Mountains though the Northern Blues and Wallowas, creating winter
weather conditions. Lower elevations might only get a dusting or
more of snow but the snow amounts quickly ramp up with higher
elevations. A frontal system moving though This afternoon and
Tonight will be the initial strong orographic forcing impetus,
followed by persist northwesterly momentum behind the system
continuing to promote light precipitation in the dendritic growth
zone beyond 24 hours, driving high mountain areas well above 6
inches of snow with time. Latest HREF ensemble mean hourly trends
begin Northern Blue Mountains snow in earnest around 8z/or late
evening, with snow continuing through late afternoon Tuesday. For
Wallowa county – where 4 inches is the lower end for advisory,
snow chances for 4 inches or more below 5400 ft are quite low (20
percent or less across the majority of that area). The Northern
Blue Mountains of Oregon (OR502) have a higher minimum requirement
of 6 inches for advisories. In either case the probabilities for
this magnitude of snow is not meeting in 12 hours. One local
community with a greater risk of some snow imp- acts is Tollgate
where there is a 70% chance of 5 inches of total snowfall, and
about a 50% chance to hit or exceed the low end 6” threshold for
advisories.
Friday through the weekend look to be a windy period with
southwest winds increasing Friday evening, remaining windy
overnight and and not appreciably diminishing until Saturday
evening. Winds will pick up again diurnally Sunday, based on NBM
trends for this period. This change to a downslope windy regime
will lead to a more marked warmup on Friday where NBM is forcing
low to mid 50s across much of the Lower Columbia Basin, Blue
Mountain foothills, central Oregon and the John Day Basin.
Russell/71
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 40 27 40 / 20 60 10 0
ALW 30 38 29 38 / 40 70 10 10
PSC 25 39 24 37 / 20 30 0 0
YKM 24 45 24 38 / 10 0 0 0
HRI 27 41 26 38 / 20 40 0 0
ELN 25 44 22 37 / 10 10 0 0
RDM 26 46 21 46 / 0 10 0 0
LGD 31 41 27 41 / 40 90 20 0
GCD 30 42 27 43 / 10 50 10 0
DLS 34 51 34 43 / 10 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
DISCUSSION...71
AVIATION...74
