608
FXUS66 KMFR 142342
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
442 PM PDT Tue Oct 14 2025

...Updated AVIATION discussion for 00Z TAFs...

.DISCUSSION...After a cloudy start to the day, skies have cleared
across most of the region. Some lingering stratus remains banked
up against the east slopes of the Warners and Cascades north of
Crater Lake, but this is gradually eroding as well. High
temperatures are running around 5 to 10 degrees warmer than this
time yesterday, but will still max out at around 5 degrees below
normal for this time of year. There are some light returns on the
radar across eastern Lake and Modoc Counties as that area remains
on the far northwestern periphery of the low pressure that passed
through the region yesterday. These light showers could continue
into the overnight period, but we don`t expect much to amount from
them.

Meanwhile, guidance shows skies remaining clear across most of the
area tonight, which will allow for much cooler overnight
temperatures compared to this morning, especially east of the
Cascades. Am skeptical of how much clearing guidance wants to hold
on to for the West Side Valleys tonight given the time of year and
recent moisture. It`s more likely that low clouds will develop again
tonight in the Rogue/Illinois/Applegate/Umpqua so temperatures
should remain above frost/freeze thresholds there. Additionally,
dewpoints are expected to remain in the upper 30s, so even if skies
do remain clear, temperatures should still remain above those
thresholds. For the Scott/Shasta Valleys in California, temperatures
will be a bit cooler, but should also remain above frost/freeze
thresholds. As high pressure nudges in and northerly flow sets in on
Wednesday, expect more widespread clearing of skies for Wednesday
night, and this is when temperatures will drop for areas east of the
Cascades (mid-upper 20s) and across northern California (low to mid
30s). At this time, it looks like a widespread frost is possible for
the Scott/Shasta Valleys, and potentially in the colder portions of
the Rogue/Illinois/Applegate Valleys Wednesday night. Confidence is
lower for the valleys north of the OR/CA border due to the potential
for another night of cloud cover. After seeing if or what the extent
of cloud cover develops tonight, it should help boost confidence one
way or the other on where Frost Advisories are warranted for
Wednesday night. From Thursday night onward through the weekend,
overnight temperatures trend warmer so frost/freeze concerns
diminish.

Otherwise, quiet weather is in store for much of the week with
afternoon highs staying on the cool side and hovering around 5
degrees below normal (upper 60s for the West Side/upper 50s across
the East Side). Temperatures trend slightly warmer on Friday and
even more so on Saturday as high pressure moves over the Pacific
Northwest. Active weather returns late in the weekend with models
and ensemble guidance in rather good agreement on the next system
arriving at the coast late Saturday night/early Sunday morning.
/BR-y

&&

.AVIATION...15/00Z TAFs...VFR levels are present across northern
California and southern Oregon to start the TAF period. Circulation
low pressure system passing to the southeast is supporting some
areas of cloud cover and slight chances for showers in southernmost
Modoc County, but overall the TAF period looks to be free of active
weather.

Stratus development is still somewhat expected for west side valleys
given the amount of precipitation over the weekend, but these
developments are absent in current guidance. Forecast conditions for
tonight do include drier air in west side valleys, which would limit
or prevent overnight development. The observations at the 06Z
forecast will help to further gauge chances for stratus development.
For this TAF period, lower flight levels remain absent from the
forecast. -TAD

&&

.MARINE....Updated 200 PM PDT Tuesday, October 14, 2025...Seas will
remain steep to very steep today, highest over the outer waters,
then will gradually diminish tonight through Wednesday. Meanwhile,
lighter winds return Wednesday into Thursday morning. North winds
and steep seas increase again Thursday afternoon into Friday with
small craft advisory level conditions likely south of Cape Blanco.
Long period swell could arrive Friday. -Spilde/BPN

&&

.BEACH HAZARDS...Updated 230 PM PDT Tuesday, October 14,
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 (7-9 ft at ~17-19 seconds) arriving later this week,
probably sometime Friday and lasting into Saturday before decaying.
This could 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.
We`ll be evaluating this potential and a beach hazards statement may
be necessary at some point. -Spilde/BPN

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT
     Wednesday for PZZ350-356-370-376.

Hazardous Seas Warning until 5 PM PDT this afternoon for PZZ370-
     376.

&&

$$

MNF/BPN