428
FXUS66 KMFR 051753
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
952 AM PST Thu Nov 5 2026

...Updated AVIATION discussion for 18Z TAFs...

.KEY MESSAGES...

* High pressure will continue to build into Thursday and Thursday
  night with more fog and freezing fog Thursday night.

* Temperatures trend warmer Friday into Saturday.

* Another cold front will bring wetting rain to locations west of
  the Cascades Saturday night into Sunday morning.

* The active weather pattern continues into next week.

&&

.DISCUSSION...

Not a lot going on this morning other than the freezing fog east
of the Cascades and some fog and low stratus closer to the coast.
The freezing fog is the bigger issue as KLMT visibility is
dropping below 1/4 a mile at times. Last night some wind seemed to
push visibilities higher. We`re not under a really strong ridge,
so thinking the visibility could bounce around a bit this morning
with a little wind, so we`re not issue a freezing fog advisory.
None the less, some surfaces could still be slick this morning.

A dissipating cold front is providing some lift over the region
and the front actually kicked off a few showers near the coast.
High pressure should be building into the day with 500 mb heights
rising into 9Z Friday. However, models show a mix of mid level
and high level clouds moving over the forecast area this afternoon
and evening.

Fog and freezing fog should fill into the valleys yet again as
this mini ridge sets up Thursday night. The rapid refresh
ensemble forecast system (REFS) is showing scattered high cloud
cover Thursday night into Friday morning. However, we`ve seen fog
form many times under these thinner clouds over the last few days.

By Friday, a deeper southwest flow will set up over the region
with the leading edge of an atmospheric river hitting Washington
state and parts of British Columbia. This warmer flow should
result in some warming temperatures by Friday and more notably
into Saturday with highs in the upper 60`s and perhaps some 70`s
within valleys west of the Cascades.

Heading into Sunday, models show a low deepening to the west of
Canada. That low will launch a cold front into the Pacific
Northwest by Saturday night. The cold front isn`t that dynamically
strong, although we`ll see some gusty southerly winds along the
coast in addition to wetting rain. The latest PoP forecast has a
90% chance of rain along the coast with those probabilities
lowering farther to the east with dry conditions in Lake and Modoc
Counties Sunday morning. We`re not expecting any impacts with this
rain during the weekend.

Heading into next week, we still have moderate to low confidence
in the forecast. Ensembles are showing an active weather pattern,
although where the atmospheric river and moisture hit is still in
question. Some ensemble members show all the precipitation well to
our north while others hit southern Oregon and northern
California. Some ensemble members are definitely on the drier side
with some light rain or no rain while others bring a heavier rain
with 2 to 3 inches falling over 6 hours. In any case, the PoP
forecast is pretty consistent in the 20-40% range for most of
next week, although it does move a bit higher towards 60% by
Thursday the 12th.

-Smith

&&

.AVIATION....05/18Z...Fog or low ceilings remain in some valleys
across northern California and southern Oregon, although there are
signs of improvement. North Bend has cleared out and visibilities in
the Umpqua Valley are starting to improve while fog remains at the
Klamath Falls terminals. With stable weather expected today, buildup
looks to dissipate by the afternoon. Marine stratus looks to return
to the coast and freezing fog is expected to return to Klamath Falls
tonight. While some guidance also has fog returning to the Umpqua
Valley, drier conditions may also limit that possibility. MVFR
ceilings have been included in the TAF for Roseburg, but lower
visibilities would have similar timing.

Other areas generally look to remain at VFR levels through the TAF
period under passing high clouds. -TAD

&&

.MARINE...Updated 215 AM PST Thursday, November 5, 2026...Seas will
remain high as a swell around 10 to 12 feet at 15 to 17 seconds
moves through the waters. These conditions will be hazardous to
smaller crafts through the weekend. The sea state will worsen around
Sunday as another cold front could produce gale force winds. A low
deepening in the gulf of Alaska should produce a swell around 16
feet at 13 to 16 seconds Sunday afternoon or evening.

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST
     Saturday for PZZ350-356-370-376.

&&

$$