356
FXUS66 KMFR 162122
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
222 PM PDT Thu Oct 16 2025

.DISCUSSION...Low clouds and fog have just cleared from portions
of the Umpqua Basin just in time for high clouds to start moving
in overhead. These higher clouds are associated with a weak upper
level trough that is passing just to our north, and will have very
little other effect on our forecast area.

Through Saturday, conditions will be relatively quiet across
southern Oregon and far northern California, with temperatures
gradually warming each day, no rain expected, and overnight/early
morning fog and/or low clouds along the coast and in area valleys
each day.

The first system of concern arrives late Saturday into Sunday as
an upper level trough and associated front pass through the
region. Models have backed off considerably on wind speeds and
rainfall amounts with this system, mainly as a result of a
northward shift in the storm track. With snow levels remaining
above 6000 feet during the bulk of the pre-frontal precipitation,
and dropping only to about 5000 with post-frotnal showers, no
significant winter impacts, if any, are expected. Light rain will
likely begin at the coast late Saturday evening, spread to the
rest of the area overnight, then taper off by Sunday afternoon,
although some post-frontal showers could persist later in the day
within the Umpqua and Coquille valleys due to ongoing onshore
flow. Rainfall amounts will be light, more of a nuisance to
outdoor activities than a beneficial rain. Breezy winds are
expected as well, but nothing out of the ordinary for this time of
year.

Next week, the area will remain under weak ridging aloft, and
although a weak trough may pass by Tuesday, there is little
moisture associated with it so rain chances will be very low.
Otherwise, temperatures will be very seasonable, staying right
around or just above normal for this time of year.

Of note, there is a system that is expected to arrive late in the
week or early next weekend that could have more significant
impacts in wind, rain, high surf, and mountain snow. Just about
every member of all the model suites shows this system arriving in
our area, but there is a wide range of timing and strength
between the solutions, so confidence is low for any given forecast
parameter. We will be keeping a close eye and will update the
forecast as details become apparent. -BPN



&&

.AVIATION...16/18Z...Along the coast and just offshore. VFR
conditions will continue into most of tonight, with IFR ceilings and
visibility developing between 9-11z, including North Bend. Some of
the guidance suggest lower conditions could develop prior to 9z, but
light offshore flow is expected which should delay the onset of low
clouds and fog.

Elsewhere, VFR conditions will continue into most of tonight, with
stratus likely to form in the Umpqua Basin, Illinois Valley and
portions of the Rogue Valley. The lower conditions will likely
result in IFR ceilings and visibility at the Roseburg terminal.
Medford airport should remain VFR through the TAF period, but patchy
fog in the vicinity of the terminal is possible towards 14z.

East of the Cascades, VFR conditions will prevail through the TAF
period. Patchy shallow fog with limited vertical visibility could
form at Klamath Falls after10-11z, but  confidence is not high
enough to include it in the TAF. Later shifts will need to take
another look at this. -Petrucelli


&&

.MARINE...Updated 200 PM PDT Thursday, October 16, 2025...Moderate
to occasionally strong north winds will persist through Friday night.
The strongest winds and highest steep wind driven seas will be south
of Cape Blanco. Additionally, a long period northwest swell will move
into the waters late Friday afternoon and lasting through Saturday
afternoon with swells getting close to 12 feet.

Seas will briefly diminish Saturday night into Sunday morning, then
another long period northwest swell will move into the waters Sunday
afternoon through Sunday night. Guidance shows swells peaking out
between 18-19 feet Sunday night, before gradually diminishing
during the day Monday.

A weak cold front will move through the waters late Saturday night,
with a brief uptick in south winds, then winds will shift to the
west and diminish early Sunday morning as the front moves onshore.
-Petrucelli


&&

.BEACH HAZARDS...Updated 300 PM PDT Thursday, October 16,
2025...We`re heading into the time of year where distant storms
generate swells with long periods. These long-period swells harbor
more energy than a typical set of waves and have the ability to run
up much farther on the beaches. Model guidance is showing a long-
period swell (9-11 ft at ~17-19 seconds) arriving Friday afternoon,
with the hazard peaking during the night, and lasting through the
Saturday morning. This will pose a threat for sneaker waves at area
beaches. We call them "sneaker waves" because they aren`t
particularly large or even high waves, but because they exhibit such
high energy, they can suddenly wash over rocks, logs and jetties
without much warning. -Petrucelli


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Beach Hazards Statement from Friday afternoon through Saturday
     morning for ORZ021-022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 PM PDT Saturday
     for PZZ356-376.

     Small Craft Advisory from 8 PM Friday to 8 PM PDT Saturday for
     PZZ350-370.

&&

$$