798
FXUS66 KMFR 160113
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
513 PM PST Wed Jan 15 2025

...Updated the Aviation Section...

.AVIATION(00Z TAFs)...A patch of valley fog has persisted in the
Umpqua Valley this afternoon, including Roseburg. There is also an
area of stratus near shore between Bandon and Gold Beach. Otherwise,
conditions are VFR.

Westside valley fog is expected to follow the typical diurnal
pattern tonight with LIFR developing by late evening and expanding
in coverage overnight into Thursday morning. LIFR stratus near the
coast, including North Bend and the Coquille Valley, is also
expected to expand overnight.

During Thursday, west side inland valleys are expected to follow the
typical pattern of gradual lifting and erosion of the stratus to VFR
in the afternoon. Meantime, the coastal stratus is expected to lift
to MVFR but thicken during the day.

A weak front is expected to enhance the re-formation of valley
LIFR/IFR Thursday night, primarily for the west side, but with east
side patches possible as well. -DW

&&

.MARINE...Updated 230 PM Wednesday, January 15, 2025...Wind speeds
will be relatively light the next couple of days, but a thermal
trough will return late Thursday/Friday morning. This will result in
breezy/gusty northerly winds and building steep seas in most outer
waters and possibly as close as 5 nm from Cape Blanco and Cape
Sebastian. A Small Craft Advisory is in place from Thursday at 4 PM
through Friday at 7 AM. Beyond this period, very steep and hazardous
seas are possible south of Port Orford from late Friday morning
through the day Saturday. Future products will cover the development
of very steep and hazardous seas. Areas of advisory level seas
remain in the forecast through Monday.

&&

.BEACH HAZARDS...Updated 230 PM PST Wednesday, January 15,
2025...Another episode of sneaker waves will be possible Saturday
afternoon through Sunday afternoon. This would be due to a
combination of northerly wind waves, northwest swell at 11 seconds,
and a long period west-northwest swell at 22 seconds. Improving
conditions are possible Sunday afternoon/evening.

Sneaker waves are a type of wave that can run higher up the beach
than a normal wave. Sneaker waves can possibly wash over pathways or
rock outcroppings. They can lift and carry logs, which can then
strike or pin beachgoers. Sneaker waves can knock a person off their
feet and carry them out to deeper waters, where hypothermia becomes
possible. Sneaker waves can pose a lethal threat. As these
conditions may occur while the sun is down, visibility will be
limited. Always keep your eyes on the sea and use extra caution.

&&

.PREV DISCUSSION... /Issued 249 PM PST Wed Jan 15 2025/

DISCUSSION...

Fog and low clouds are still burning off this afternoon in parts
of the Illinois and Umpqua Valleys. Temperatures are warming
quickly and we`ll see temperatures top out in the upper 40`s and
lower 50`s this afternoon. Clear skies with an inversion and
plenty of dry air aloft should help us radiate heat efficiently
later this evening into tonight. Therefore, we should see more of
the same later tonight with more dense fog and freezing fog.
Temperatures might trend a few degrees warmer compared to last
night, although freezing fog remains more likely in the Rogue and
Illinois Valleys with dense fog in the Umpqua Valley. We opted not
to go with another dense fog and freezing fog advisory as the
inversion shouldn`t be as strong, although visibilities should be
hovering around 1/4 a mile for most of the night.

Heading into Thursday, not much will change with what we`ve seen
most of this week with mostly clear skies and the fog clearing out
around the afternoon hours. Afternoon high temperatures might
trend lower in a few locations as the ridge is not as strong
Thursday afternoon.

By Thursday night into Friday morning, a dry cold front will push
down the Oregon coastline with temperatures trending cooler into
much of the weekend and next week. The probability for
low temperatures less than 28 degrees is fairly high(~80-100%)
for many inland locations Saturday morning through Monday morning.
East of the Cascades, Summer Lake and locations in the high
desert will see temperatures in the lower teens. Definitely not
extremely cold, although one could consider these lower
temperatures unusually cold even for the middle of January.
However, we`ll warm up to fairly normal temperatures for highs as
skies remain clear outside of the fog.

Overall, pretty quiet into next week with ensembles keeping the
region dry. We looked through all the ECWMF members and there are
some(~10-15%) members predicting precipitation around 18Z Thursday the
23rd and 6Z Friday the 24th. The rest keep us pretty darn dry
through the next 10 days.
-Smith

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Air Stagnation Advisory until noon PST Friday for ORZ021-023>026-
     029>031.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 4 PM Thursday to 7
     AM PST Friday for PZZ350-356-370-376.

&&

$$