Winter Storm Warning 1, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
1021 AM PST Fri Jan 2 2026

.DISCUSSION...Updated aviation, marine and coastal flooding
discussions.

.AVIATION...02/18Z TAFs...We're in a relative break between
weather systems today. Conditions are LIFR in fog/low clouds in the
valleys west of the Cascades, including at Medford and Roseburg.
It'll take a while, but we do expect conditions to break out this
afternoon as pressure gradients increase allowing the low-level
inversion to break. With flow aligning with the Rogue Valley, we
also expect SE winds to mix down to the surface and become gusty at
the airport around or after 3 pm. It isn't out of the question we
see some gusts approach 35 kt, so an Airport Weather Warning (AWW)
could be necessary. Winds will also increase at Klamath Falls with
possible peak wind gusts in the 30-35kt range. We'll continue to
monitor for AWW. Persistent upslope flow into the Mt. Shasta region
will maintain light precip there with a mix of IFR/MVFR conditions,
but downslope into the Shasta Valley will bring VFR there. It pretty
much goes without saying that this type of pattern results in at
least low-level turbulence out there, and also the possibility of
low-level wind shear (LLWS). So, be aware of those potential
hazards.

The next front will approach from the SW this evening and winds
aloft will continue to increase. LLWS potential increases at most
TAF sites where low-level flow is blocked/capped under an inversion.
Light rain will spread northward into the area which could result in
areas of MVFR and higher terrain obscuration. Models are showing
fog/low clouds again in some areas (Roseburg/Medfrod). While this is
possible (I've seen it all here), it is less likely tonight,
especially in Medford, due to the stronger winds aloft. It would
take winds to die off quickly and a stronger low-level inversion to
redevelop. This is most likely at Roseburg, so we've indicated that
there and left it out of Medford for now. -Spilde

&&

.MARINE...Updated 900 AM PST Friday, January 2, 2026...Seas will
continue to build today as southerly winds increase. Conditions
worsen beyond 10 nm from shore this afternoon with gales and very
steep and hazardous seas expected. Winds will be comparatively
lighter (but still gusty) over the inner waters, which will maintain
steep seas hazardous to small craft.

Saturday and Saturday night, another stronger front moves into the
waters with low pressure nearing the coast. Expect widespread gales
and very steep seas for all waters which will then linger into
Sunday. Expect the strongest winds with this front with seas
forecast to peak near 20 feet Saturday night, dominated by wind seas
and fresh south swell. South winds persist but trend lower on Sunday
and very steep seas may continue through the day. Then, late Sunday
night into Monday, models support steep seas with a mix of northwest
swell and lingering fresh south swell. -Spilde

&&

.COASTAL FLOODING...Updated 900 AM PST Friday, January 2, 2026...
High astronomical tides and storm systems offshore the next few days
could result in minor coastal flooding of Coos Bay and estuaries
during times of high tide. The highest risk of coastal flooding will
be associated with the high tides (1-2 hours before and after) this
morning into early this afternoon and again Saturday morning into
early Saturday afternoon. -Spilde

&&

.PREV DISCUSSION... /Issued 840 AM PST Fri Jan 2 2026/

DISCUSSION...Fog has settled into the Rogue Valley, with road
cams showing low visibilities between Phoenix and Central Point.
Fog appears to be present into Grants Pass and the Umpqua Valley
as well, but to a lesser degree. The lighter fog should clear out
through the morning, while the thicker fog in central Medford may
stick around into the afternoon. Light showers continue in parts
of Siskiyou County, but overall precipitation expectations are
minimal today. A combination of high tides and gusty winds make
coastal flooding a concern for low-lying roads and estuaries near
Coos Bay this morning into Saturday morning. A Coastal Flood
Advisory is in place to further highlight these concerns.

An approaching low pressure system will bring widespread
precipitation tonight into Saturday, with the highest amounts in
western Siskiyou County and the Mount Shasta region. Snow levels
look to remain at 5500-6500 feet, keeping winter weather concerns
to the highest terrain. Hazardous winds are also expected tonight
and into Saturday for the Shasta Valley and east side terrain,
with gusty winds possibly flowing into the southeast Rogue Valley.

Please see the previous discussion for more details on the short-
and long-term forecast. -TAD

AVIATION...02/12Z TAFs...A warm front is lifting north of the area
tonight. Some light precipitation is lingering in the mountains and
along the coast, but steadier precipitation persists due to upslope
flow in northern California (especially the Mt. Shasta region). MVFR
to IFR conditions have redeveloped overnight in parts of the Umpqua
Basin, and fog is bringing LIFT conditions to the Rogue Valley. This
will linger this morning. Breezy south to southeast winds impact the
Shasta Valley, East Side, and the southern half of the Rogue Valley
this afternoon and through the evening. This should bring improving
ceilings to most areas, though upslope areas like the Mt. Shasta
region could hold onto lower conditions.

The next chance of rain arrives towards the end of the TAF period,
and it has been added for the coast first before making its way
inland. Fog has been added to the Medford TAF, however it will
depend how quickly the stronger winds of the afternoon wind down.
-Spilde/-9

MARINE...Updated 200 AM PST Friday, January 2, 2026...Steep seas are
present in all waters. Southerly winds will increase today.
Conditions worsen beyond 10 nm from shore this afternoon with gales
and very steep and hazardous seas expected. Winds will be
comparatively lighter (but still gusty) over the inner waters, which
will maintain steep seas hazardous to small craft.

Saturday and Saturday night, another stronger front moves into the
waters with low pressure nearing the coast. Expect widespread gales
and very steep seas for all waters which will then linger into
Sunday. Expect the strongest winds with this front with seas
forecast to peak near 20 feet Saturday night, dominated by wind seas
and fresh south swell. South winds persist but trend lower on Sunday
and very steep seas may continue through the day. Then, late Sunday
night into Monday, models support steep seas with a mix of northwest
swell and lingering fresh south swell. -Spilde

PREV DISCUSSION... /Issued 243 PM PST Thu Jan 1 2026/

SHORT TERM...Active weather will continue through the weekend as
a couple low pressure systems move through the region. This will
bring a potential for impacts due to strong, gusty winds and
mountain snow.

Key Points
* Light rain today with high snow levels above 6500 ft

* Expect a break during the day Friday with mainly dry weather,
  except some areas of rain likely in southern Siskiyou County.

* The next system moves in late Friday with gusty winds in the
  Shasta. Rain and higher mountain snow (above 6000 ft).

* On Saturday, a low moves along the coast, with strong winds
  possible, especially at the Curry Coast and in the Shasta
  Valley. Heavy snow possible in the mountains above 5000 ft in
  Siskiyou County.

* Rain and mountain snow continues on Sunday, heaviest in the
  Mount Shasta region and over Curry County.

* King Tides may result in localed flooding along the coast this
  Friday and Saturday.

Rain is spreading over the area today as a low moves inland to the
south. Snow levels are high, generally above 6500 feet.
Precipitation will lift north tonight with mainly dry weather
expected during the day Friday, except in the Mount Shasta region
where light rain may persist.

This break will be brief as a low pressure and a front to the
west will approach the area on Friday. This front moves inland
Friday evening through Saturday morning and will send another
round of light to moderate rain and mountain snow into the area.
Snow levels are expected around 6000 feet during this period, so
any snow impacts will be limited. Ahead of the front, the
National Blend of Models (NBM) and ensembles support gusty winds
developing in the Shasta Valley and over higher terrain. Gusts of
45 to 55 kt are likely with a potential for brief gusts to 60 mph.
The HREF shows a probability of 80% of winds gusting to 50 mph
near Weed and Gazelle and 40% chance for winds gusting to 60 mph.
We have issued a wind advisory for these conditions in the Shasta
Valley, with strongest winds expected in the Gazelle to Weed area
late Saturday afternoon through Saturday night.

Then, for Saturday afternoon through Sunday morning, ensembles
are showing good agreement with a surface low moving towards the
southern Oregon coast, inside of 130W longitude. This low will
send a strong front onshore Saturday afternoon and evening.

Strong winds Saturday into Saturday night:

As the front moves onshore, expect a strong low level jet to move
over the area. This is likely to bring strong, gusty winds to the
area, strongest for the Curry coast, mountains and Shasta valley.
Along the coast, models indicate a 70 to 80 kt 925 mb jet moving
onshore late Saturday afternoon and early evening. Inland, models
show a 60 to 70 kt 700 mb jet moving overhead. Additionally, the
Medford to Redding surface pressure gradient is forecast to
increase to -7 to -8 late Saturday afternoon and Saturday
evening, based on latest model solutions. This combined with a 60
to 70 kt jet aloft at 700 mb supports the potential for strong
winds to surface in the Shasta Valley. Gusty winds are also
possible across higher terrain east of the Cascades and in the
Summer Lake area. Current high resolution models support gusts up
to 45 mph in the Summer Lake area and mountains east of the
Cascades and gusting to around 30-40 mph in valleys east of the
Cascades. West of the Cascades, breezy to gusty winds in valleys
are likely on Saturday. Models indicate gusts up to 35 mph in the
southern Rogue Valley, near Ashland, and in the Scott Valley in
western Siskiyou County. We will monitor this with additional
model runs as the exact track of the low may result in changes in
the wind forecast.

Saturday/ Sunday Rain and Mountain snow:

Rain and mountain snow will be concerns Saturday through Sunday
as this front moves gradually moves across the area. Snow levels
are expected to lower to around 5500 feet by Saturday evening and
then down to 5000 feet Saturday night into Sunday morning.
Heaviest precipitation is expected across Curry, southwest
Josephine and western and southern Siskiyou counties. This
combined with lowering snow levels is expected to bring some
impacts from heavy snow to the mountains in western and southern
Siskiyou County, above 5000 ft. This will mainly affect the higher
roads and passes, including higher portions of Sawyers Bar road
and the Mt. Shasta ski park road. Gusty winds over exposed
mountain areas will also result in limited visibility in falling
snow. A winter storm watch remains in effect for mountains in
Siskiyou county. For southwest Oregon, expect mainly light to
locally moderate snowfall, mainly over the Southern Oregon
Cascades, including in the Diamond Lake and Crater Lake areas ,and
higher portions of the Siskiyous. Light snow is also likely for
higher mountains east of the Cascades.

Rain will be moderate to heavy for many areas west of the
Cascades, especially across Curry and southwest Josephine below
5000 ft in western/southern Siskiyou County. Current hydrologic
forecasts from the National Water Model support stream rises but
only isolated or limited potential for minor stream flooding,
mainly in south- central Siskiyou County near and south of Mount
Shasta City. Localized, minor stream/urban flooding due to heavy
rain, especially if there are blocked ditches or storm drains, is
the main concern. Ponding on roadways in heavy rain is also
possible.

Rain and snow will lessen from west to east on Sunday as the front
moves to the east. However, another weak low may move into
northern California reinforcing precipitation, especially over
Siskiyou County Sunday afternoon and evening.

King Tides:

Another impact along the coast will be King Tides. These are high
astronomical tides. These tides combined with an increase in
surge associated with storm systems offshore are expected to
result in minor coastal flooding at times of high tide, mainly
Friday morning and early Friday afternoon and again Saturday
morning into early Saturday afternoon. Please see the coastal
flood discussion below and the CFWMFR for details.

LONG TERM...Sunday nigh through Thursday...Sunday night into
Monday, ensemble solutions point to another low and upper trough
moving into the region from the northwest, bringing another round
of precipitation. This low may shift south of the area Monday
night and Tuesday. However, an active jet stream to the north,
will likely send another front and upper trough into the region
Tuesday night through Thursday. As the upper trough moves in, this
scenario would result in a showery pattern and colder air over
the area late Wednesday into Thursday. There is lower confidence
on the exact timing and details for this period. This scenario
would result in lower snow levels (with the NBM showing snow
levels down to around 2000-3000 ft)and the highest probability of
precipitation will be for the coast and Douglas County northward.

COASTAL FLOODING...Updated 200 PM PST Thursday, January 1,
2026...High astronomical tides and storm systems offshore the next
few days could result in minor coastal flooding of Coos Bay and
estuaries during times of high tide. The highest risk of coastal
flooding will be associated with the high tides (1-2 hours before
and after) Friday morning and early Friday afternoon and again
Saturday morning into early Saturday afternoon. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 4 PM this afternoon to 4 AM PST Saturday for
     ORZ026.

     High Wind Watch from Saturday morning through late Saturday
     night for ORZ022.

     Coastal Flood Advisory until 1 PM PST Saturday for ORZ021.

CA...Winter Storm Watch from Saturday afternoon through Sunday
     evening for CAZ080-082-083.

     Wind Advisory from 4 PM this afternoon to 4 AM PST Saturday for
     CAZ081.

     High Wind Watch from Saturday morning through late Saturday
     night for CAZ081.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST this
     evening for PZZ350-356.

     Gale Warning from 10 PM this evening to 7 AM PST Sunday for
     PZZ350-356.

     Gale Warning until 7 AM PST Sunday for PZZ370-376.

&&

MAS/MAS/MAS