370
FXUS66 KMFR 231813
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1013 AM PST Sun Nov 23 2025

...Updated AVIATION discussion for 18Z TAFs...

.DISCUSSION...Fog remains in area valleys and basins this morning,
although there are signs of clearing on Tripcheck roadcams. Dense
fog remains near the Medford and Klamath Falls airports, and may
be present along parts of I-5 through Medford. Visibility and
traction may be affected by lingering fog, so extra caution while
traveling is advised.

A combination of daylight and an approaching front should help to
clear out lingering fog. Light rain showers remain in the forecast
for areas west of the Cascades this afternoon into early Monday
morning, while activity east of the Cascades will be more
isolated.

Please see the previous discussion for more details on the short-
and long-term forecasts. -TAD


&&

.AVIATION...23/18z TAFs...Fog around the Medford and Klamath Falls
terminals and low ceilings over the Roseburg terminal are keeping
levels at LIFR this morning, although there are slight signs of
improvement to start the TAF period. Low ceilings and visibilities
in these areas could continue into the late morning or early
afternoon.

Above the fog, high and midlevel clouds are moving in ahead of an
approaching weak front. Rain showers will be possible west of the
Cascades this afternoon into early Monday morning. For some low-
lying areas, refreshed surface moisture may help fog return later
tonight into early Monday morning. -TAD


&&

.MARINE...Updated 300 AM PST Sunday, November 23, 2025...Steep
seas will continue today due to long period west to northwest
swell. A weak front will bring a brief period of south to
southwest winds along with some rain through this evening. Sub-
advisory north winds return overnight into Monday. A warm front
will pass by to the north Tuesday and this will bring another
round of southerly advisory level winds around midweek. -Spilde

&&

.BEACH HAZARDS/HIGH SURF...Updated 300 AM PST Sunday, November
23, 2025...Wave heights of 10-15 feet with periods of 15-17
seconds will bring an increased risk of sneaker waves at the
beaches through this evening. A Beach Hazards Statement is in
effect for sneaker waves that can run up significantly farther on
beaches than normal. 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
today. -Spilde


&&

.PREV DISCUSSION... /Issued 326 AM PST Sun Nov 23 2025/

DISCUSSION...Leveraging GOES-West nighttime microphysics
satellite imagery early this morning, have decided to go with a
dense fog advisory for portions of the Rogue, Illinois,
Applegate, Umpqua and Coquille valleys until 10 am PST. Web cams
are even foggier across a larger area than they were yesterday,
basically all up and down I-5 from Roseburg to Medford and also
the state highways (199, 42, 62, 140, 238, 138) that branch off
from I-5. Please use extra caution if traveling this morning.
Cyclists and pedestrians should also wear bright or reflective
clothing to make it easier for drivers to see you. In addition to
the dense fog, which could limit visibility to below 1/4 of a mile
at times, temperatures are near or even a touch below freezing,
especially in the Rogue Valley around Medford. This could result
in some slick spots on roadways, especially those that are
elevated like bridges and overpasses.

Some areas had difficulty getting rid of the fog/low clouds
yesterday (it`s getting to be that time of year with low sun angle
and shorter days), but there is a front approaching from the NW
today and expect this to lift the fog (at least somewhat). Some
high clouds are already advancing into the area and we expect some
stratus to develop with light precip (rain) breaking out along
the coast this afternoon. Precipitation then spreads inland this
evening/overnight. Upper level support for this front is meager,
so while precipitation will make it to the mountains (Cascades
and the Siskiyous of western Siskiyou County), it will mostly fall
apart south and east of there. Amounts in the west side valleys of
0.05-0.15" will be common with 0.20-0.40" most likely along the
coast and in the mountains (maybe isolated amounts up to 0.50").
Highway 97 could get a little late tonight/early Monday too, but
most east side areas and NorCal will get skipped over.
Accumulating snow with the front will be mostly above 5500 feet
(2" or less). Snow levels drop to around 3500-4000 feet Monday
morning, but precip should be mostly done by then.

It dries out all areas Monday afternoon/night with surface high
pressure building in, so we`ll go back into a nighttime/morning
low clouds/fog regime for west side valleys. Tuesday/Wednesday, a
warm front will pass by to our north and west. This will allow
snow levels to surge back to around or even above 7000 feet. Most
areas will remain dry, but this could result in some light rain
across NW sections. Highest PoPs (~60-70%) will be along the coast
north of Cape Blanco and along the Lane/Douglas County border.
Overall, travel weather leading up to Thanksgiving Day should be
OK, except for the potential for low clouds/fog during the
nights/mornings.

The upper trough offshore will eventually bring a cold front to
the coast Thanksgiving Day/night. There are many different
scenarios with this system, but the gist remains the same,
highest PoPs from the coast to the Cascades with little, if any
precip reaching south and east of the mountains. In fact, PoPs in
NE California don`t get above 10% until Friday. While uncertainty
in the details is fairly high for late in the week into next
weekend, models are fairly consistent in amplifying an upper ridge
along 140W into eastern Alaska. In these scenarios, usually we
get a system to come southward along the BC coast and eventually
carve out an upper trough in the western US/Great Basin. Best
estimate on timing of the initial system would be Friday
night/Saturday, followed by a shot of colder air (below normal
temps) and lower snow levels pushing southward out of western
Canada behind that. Given the expected position of the ridge
(between 130-140W), the coldest air would be felt east of the
Cascades. We`ve got plenty of time though to assess the details
though, so stay tuned. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Beach Hazards Statement through this evening for ORZ021-022.

     Dense Fog Advisory until 10 AM PST this morning for ORZ021-023-
     024-026.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 AM PST Monday
     for PZZ350-356-370-376.

&&

$$