432
FXUS66 KMFR 020554
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
954 PM PST Mon Dec 1 2025

...Updated AVIATION Discussion for 06Z TAFs...

&&

.AVIATION...02/00z TAFs...A layer of cirrus is lingering over the
area, supporting continuing VFR levels across the area. Once this
layer moves to the south, low ceilings or valley fog may be possible
in low-lying areas, especially west of the Cascades. IFR to LIFR
ceilings or visibilities will be possible late tonight into early
Tuesday morning in areas where development does occur. An
approaching shortwave trough could provide enough mixing to help
clear out any overnight development before Tuesday afternoon. VFR
ceilings are expected with the trough, and precipitation will most
likely be nonexistent or extremely isolated. -TAD

&&

.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.

&&

$$