772
FXUS66 KMFR 190533
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
933 PM PST Tue Nov 18 2025

.DISCUSSION...Updated Aviation Section...

&&

.AVIATION...19/12Z TAFs...Ceilings have persisted into this evening
for many valleys west of the Cascades, including most areas south
and east of the Rogue-Umpqua Divide, including Medford and
Montague/Yreka. Ceilings are around 3000 feet (borderline MVFR) and
could last through much of tonight. There is a chance ceilings lift
or even scatter out for a time by morning, and if they do, those
same valleys are likely to fog in under IFR/LIFR conditions.

With high pressure building in and plenty of low-level moisture, we
expect areas of valley fog and low clouds to redevelop this evening
and fill in again overnight into Wednesday morning. This will bring
widespread valley IFR/LIFR and to most TAF sites. Offshore flow
could prevent the fog/low clouds at North Bend, so a VFR forecast is
indicated there through Wednesday morning. Most areas should clear
to VFR by late morning or early afternoon, but some locations may
not fully clear at all. The end of the TAFs show the incoming
rainfall for sites as the next front moves inland. -Spilde/BPN

&&

.PREV DISCUSSION... /Issued 220 PM PST Tue Nov 18 2025/

DISCUSSION...Satellite image shows a lower cloud deck persisting in
the Rogue, Illinois, Applegate, and Shasta Valleys and the clouds
have been slow to erode over the past few hours. Meanwhile, lower
clouds in some of the valleys east of the Cascades, in particular
Lake County have also been slow to burn off. iIt`s possible these
areas may not break out at all or at the very least late in the
afternoon.

Guidance tonight is in pretty good agreement for low clouds and
patchy to areas of fog to form for the interior westside valleys
again later tonight into Wednesday morning, and the valleys east of
the Cascades. For the westside valleys, this should be enough to
keep temperatures from dropping near or below freezing as the cloud
layer and fog will slow down the amount of cooling tonight.

The pattern overall will remain rather quiet for the rest of the
week into next weekend. The exception will be Wednesday night into
Thursday as an upper trough will move into the area bringing
precipitation, but much like the last couple of times, the low will
split from the main flow and push south into northern Cal. This will
limit the amount of precipitation we get in our area. Snow is
expected to be confined to the mountains. Even then 24 hour snowfall
accumulation will be an inch or less along the Cascades and around
Mount Ashland and the higher terrain east of the Cascades. Meanwhile
snowfall amounts will be higher at Mount Shasta Ski area.

As the upper low splits and weakens, precipitation during the day
Thursday will diminish, but will tend to linger longer in Northern
California.

The upper low will move south into California Thursday night with
dry weather likely. However, low level moisture from Wednesday night
and Thursday morning precipitation will be high, thus setting the
table for low clouds and fog again for the interior valleys.

Friday through the weekend is likely to be dry as upper ridging
nudges in from the west as the cutoff low moves towards southern
California. The upper flow will likely remain westerly with the
ridge remaining over the area Saturday through Sunday. This will
likely keep the storm track farther north, this keeping our area
dry. There`s good agreement among the operational models with the
overall pattern this weekend. The operational models, the majority
of the individual ECMWF (88 percent), and all of the GFS ensemble
means show no precipitation in our area Sunday. Additionally, the
clusters are also in good agreement into Sunday with upper ridging
over our area and the storm track farther north. As is typical, the
NBM solution for the weekend is too high, too far south, and inland,
especially given the above mentioned. So while we have a slight
chance to chance pops in the forecast for some locations Sunday, the
reality is we`ll end up dry.

Now it won`t be until late Sunday night into Monday where a weak
upper trough will swing north of the area and this will send a
weakening front into our area early Monday morning. The front will
weaken as it moves through the area Monday, therefore it`s possible
most of the precipitation (and it will be light) will be in the
morning with most areas dry Monday afternoon.

A cooler and drier airmass will follow Monday night into Tuesday
which the operational models show, but this is not locked in stone
with some the individual ensemble members hinting at more upper
troughing which could bring cooler and possibly unsettled weather.
-Petrucelli

MARINE...Updated 200 PM PST Tuesday, November 18, 2025...North
winds and northwest swell will gradually subside tonight with
conditions improving from north to south into Wednesday. Then,
another frontal system is expected Wednesday afternoon and night
with steep wind-driven seas. After the front passes and winds
diminish, large longer period swell arrives Thursday into Friday.
Guidance is showing the swell peaking in the 16-19 foot range at
15 seconds Thursday evening. A somewhat active pattern then
continues through the weekend, with persistent elevated seas of
slightly higher than 10 feet. -Spilde

BEACH HAZARDS/HIGH SURF...Updated 200 PM PST Tuesday, November
18, 2025...Guidance is showing a long period swell arriving Thursday
morning and persisting through Friday morning. With swells peaking
in the 16-19 foot range (15 sec period) Thursday evening, this will
result in 20-24 foot breaking waves in the surf zone. A high surf
advisory has been issued. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory from 10 AM Thursday to 4 AM PST Friday for
     ORZ021-022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST this
     evening for PZZ356-376.

     Small Craft Advisory from 1 PM Wednesday to 10 AM PST Thursday
     for PZZ350-356-370-376.

     Hazardous Seas Watch from Thursday morning through late Thursday
     night for PZZ350-356-370-376.

&&

$$