832
FXUS66 KMFR 101203
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
403 AM PST Mon Nov 10 2025

.DISCUSSION...A weak upper trough and surface frontal boundary
will settle southward and dissipate over the area today. Our area
is still under the influence of an upper ridge centered over
southern California. Like yesterday, this morning`s satellite
imagery is showing lots of high clouds streaming over the top of
the ridge (and in advance of the weak upper trough to the north).
Beneath the high clouds, low-level moisture is bringing foggy
areas to many west side valleys. Looking at web cams this morning,
the fog looks pretty dense along I-5 and in the vicinity of
Roseburg and Grants Pass. There has also been some lower
visibility here in Medford in the last hour. We have gone ahead
and issued a Dense Fog advisory, which is in effect through 9 AM
PST this morning to alert folks of the poor visibility conditions
expected through mid-morning. Conditions should improve later this
morning and into this afternoon. The upper trough will bring some
minor rain chances to the coast and into northern Douglas County,
but we`re really not expecting much, and it might be difficult to
find many locations where precipitation is measurable. South and
east of the Rogue-Umpqua Divide, after the fog this morning, it`ll
be a dry, mild day with some filtered sunshine through high
clouds.

The dry, mild pattern will persist through midweek, but breaks
down Wednesday as a deep upper trough approaches the coast. Models
are showing a fairly strong pressure gradient and mid-level flow
initially of (~50-60 kt) during the day Wednesday, which will
result in strengthening south winds along the coast and also in
the usual spots -- the Shasta Valley and over the East Side. It
doesn`t appear it will come together soon enough to meet High Wind
criteria along the coast, but gusts of 45-55 mph are expected.
Breezy to windy conditions will develop Wednesday farther inland,
especially in the Shasta Valley and over the East Side, but also
perhaps here in the Rogue Valley. It is these areas that will
likely need some sort of wind headline beginning Wednesday and
carrying into Wednesday night. Models show mid-level flow
increasing to and peaking at 65-75 kt Wednesday evening/night, so
most likely will need a High Wind Watch Shasta Valley and parts of
the East Side.

Once again snow levels will initially be very high, so
precipitation, even in the mountains, will begin as rain. It
does look like snow levels drop to around 5000 feet by Thursday
morning, then as low as 3700-4000 feet Thursday night into Friday.
Some snow will accumulate above 5000 feet, but preliminary
accumulations are generally 2-6". In terms of rainfall, this looks
like another Coast Range and into Siskiyou County event, where
amounts of 1-3 inches will be common. West side valleys will have
a good amount of downsloping, so amounts there will be less than
that (bulk of precip coming late Wednesday night into Thursday
morning), but post-frontal showers continuing Thursday in moist,
onshore flow. It`ll remain breezy and turn cooler compared to
earlier in the week. Friday is shown to be the coolest day of the
stretch with temperatures struggling to get out of the 40s in the
valleys west of the Cascades (we do have highs in the low 50s),
and most of the East Side peaking out in the upper 30s to near
40F. Snow levels will be at their lowest point Friday morning
(~3700 feet) with the trough axis shifting east of the Cascades,
but warm advection could result in high PoP, low QPF from the
coast to the Cascades. Precip chances south and east of the
mountains will be lower and generally 50% or less.

It`s a bit too early to speculate much about the weekend. Models
do try to lift the main moisture axis to our north Saturday, but
we`ll maintain a high PoP forecast along the coast and west of the
Cascades (50-90%) with much lower chances south and east of the
mountains (10-40%). The next front is indicated to approach the
coast Sunday. -Spilde

&&

.AVIATION...Dense fog has been causing havoc on TAF forecasts this
morning, going in and out of LIFR and VFR. The only one that has
behaved and maintained LIFR steadily has been Roseburg. Fog has
been coming and going at Medford, but LIFR ceiling has persisted.
The lower conditions are likely to persist through mid-late
morning before clearing to VFR in most places. Expect additional
lower ceilings due to low clouds and fog tonight into Tuesday
morning. -Spilde

&&

.MARINE...Swell dominated seas will remain below advisory
criteria today with increasing northerly winds, highest south of
Cape Blanco. North winds and steeper seas tonight into Tuesday
could result in borderline hazardous conditions to small craft.
Winds briefly ease Tuesday night, then a strong front and low will
bring gusty south winds, possibly to gale force, and steep to
very steep seas Wednesday into early Thursday followed by a high
and steep west swell Thursday into Friday. -Spilde


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Dense Fog Advisory until 9 AM PST this morning for ORZ021-023-
     024-026.

CA...Dense Fog Advisory until 9 AM PST this morning for CAZ080-081.

PACIFIC COASTAL WATERS...None.

&&

$$

MAS/MAS/MAS