650
FXUS66 KMFR 172132
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
232 PM PDT Fri Oct 17 2025

.DISCUSSION...A weak upper level impulse has passed over the area,
effectively destroying itself as it moved onshore and leaving
only some residual cloudiness along the Cascades and across the
Umpqua Basin to even show that it existed. For the rest of today
and through tomorrow, 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 continued the weakening trend from yesterday,
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-
frontal showers, no significant winter impacts, if any, are
expected. Light rain will likely begin at the coast late Saturday
afternoon, 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.

Late next week and into the weekend, a potentially strong system
or series of systems is possible with significant impacts in
strong winds, heavy rain, high surf, and heavy mountain snow.
Just about every member of all the model suites depicts a very
active storm pattern 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. For instance, the models
have trended a bit farther south with the storm track in the last
24 hours, and while this would shift the locations of heavy
rainfall, it would also lower snow levels from previous
expectations, and change prevailing wind directions, thereby
altering downslope/upslope precipitation processes. We still have
about a week to go, so there are likely to be a number of changes
across the models before a consensus is reached and confidence
improves. We will be keeping a close eye and will update the
forecast as details become apparent. -BPN


&&

.AVIATION...17/18Z...Along the coast and just offshore. VFR
conditions will continue into most of tonight. Marine stratus is
expected to develop later tonight, and persisting towards the end of
the TAF period with IFR ceilings. It will be a close call as to the
inland extent of the low clouds, but North Bend could experience
patchy low clouds and fog towards 11z.

Inland, VFR conditions will continue through the TAF period. The
exception will be in the Umpqua Basin, including Roseburg where low
clouds could develop towards daybreak with ceilings hovering towards
IFR. -Petrucelli

&&

.MARINE...Updated 200 PM PDT Friday, October 17, 2025...Moderate
to occasionally strong north winds will persist through tonight. 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 this 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. Given guidance has been consistent on this, we have
gone ahead and issued a Hazardous Seas Watch for the all of the
marine waters from late Sunday afternoon into Monday morning.
However, there;s evidence supporting the seas will be steepest over
the outer waters. Therefore further adjustments to the coverage area
may be needed.

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.

North winds are expected to increase Monday afternoon as a thermal
trough develops along the Oregon coast, which will likely result in
Small craft conditions Monday afternoon into Monday evening.

Our next attention will be focused towards the end of next week into
next weekend where there has been increasing evidence supporting a
very active pattern that could bring moderate to strong winds and
very steep seas. Details are not as clear this far out, but the main
point is to keep folks informed of potential upcoming hazards in the
long term. -Petrucelli

&&

.BEACH HAZARDS...Updated 300 PM PDT Friday, October 17,
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 this 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. After a brief break, it`s becoming likely
we`ll have another long period northwest swell moving into the
waters Sunday afternoon and lasting into Monday morning resulting in
breaking waves between 20-25 feet, thus a high Surf Advisory has
been issued. -Petrucelli


&&

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

     High Surf Advisory from 11 AM Sunday to 11 AM PDT Monday for
     ORZ021-022.

CA...None.

PACIFIC COASTAL WATERS...High Surf Advisory from 11 AM Sunday to 11
     AM PDT Monday for PZZ350-356.

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

     Hazardous Seas Watch from Sunday afternoon through late Sunday
     night for PZZ350-356-370-376.

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

&&

$$