Winter Storm in Oregon, January 3 to 5, 2026

Area Forecast Discussion
National Weather Service Medford OR
537 PM PST Fri Jan 2 2026

Updated AVIATION discussion

.DISCUSSION...An upper trough around a low pressure system will
guide activity across northern California and southern Oregon
through the weekend. For this evening, rainfall will generally be
limited to coastal counties as well as Josephine and Siskiyou
counties. Gusty winds in the Shasta and southern Rogue valleys are
expected to reach Advisory gusts tonight into Saturday morning.

On Saturday, southerly flow around the low pressure system will
focus moderate to heavy precipitation over Curry and southern
Josephine counties as well as the Mount Shasta region in Siskiyou
County. Other areas will see lighter precipitation through the day.
Saturday morning snow levels of 6500 feet drop to 5500 feet by the
evening. Heavy snowfall is expected over terrain in Siskiyou County
and moderate snowfall will be possible over the Cascades, with 40-
70% chances of Cascades snowfall rates reaching 1 inch per hour
early Sunday morning. A Winter Storm Warning for Siskiyou County
terrain and a Winter Weather Advisory for portions of the Cascades
around Crater Lake and Diamond Lake are in place from Saturday
evening into Sunday afternoon. Winds in the Shasta Valley are
expected to increase to Warning speeds late Saturday morning and
Advisory winds are expected across the Klamath Basin as well as Lake
and eastern Modoc counties.

Early Sunday morning, snow levels fall to 4500-5000 feet while
another round of precipitation arrives. In this period, snowfall
rates over the Cascades around Crater Lake and Diamond Lake have a
40-70% chance to reach 1 inch per hour. Gusty winds also continue
into Sunday morning, but are expected to ease by the afternoon as
the low pressure system weakens. Snow levels could reach 4000 feet by
Sunday evening, but decreasing amounts are expected to fall below
hazard product thresholds.

Please see the text products at NPWMFR for wind concerns and WSWMFR
for winter weather concerns for full timing and details of expected
weekend hazards.

On Monday, the last of the trough looks to push inland and to the
north while a cutoff low splits and moves south. This pattern looks
to bring another round of precipitation, although currently
widespread impacts are not expected. Periods of Advisory-level
snowfall are possible along Sawyers Bar Road west of Etna as well as
additional snowfall over terrain around Mount Shasta.

Activity eases on Tuesday morning before a Pacific front arrives in
the afternoon and brings another round of precipitation through
Wednesday. This front may bring winter weather concerns across the
Cascades, as current guidance has 10 to 15 inches of snowfall
through Wednesday. With snow levels of about 3000 feet expected,
passes through the Cascades may be impacted. Areas west of the
Cascades would see light to moderate showers, with terrain in
western Siskiyou County also expected to see 10 to 15 inches of
snowfall. Only minor activity is expected east of the Cascades on
Wednesday.

Long-term guidance generally shows a stable period on Thursday and
Friday, but ensemble agreement is not unanimous. Meteograms for both
the ECMWF and GFS ensembles show signals for activity continuing
through the end of next week, but with the lack of overall agreement
there's no clear idea on if any continued active weather would be
hazardous. -TAD

&&

.AVIATION...03/00Z TAFs...A mature cyclone lingers in the Pacific
this evening with strong southerly winds persisting across the
forecast area. Low level wind shear will develop over the valleys
later tonight as surface winds weaken below the strong southerly
aloft. Medford(MFR) and Roseburg(RBG) seem most at threat,
although we could see some LLWS near North Bend(OTH) as well.

Some model guidance is hinting at more fog, although that seems
unlikely given how much we drier air we mixed into the Rogue
Valley and the turbulence around the boundary layer tonight.
However, RBG never mixed out and LIFR ceilings will persist
overnight.

Thunderstorms could develop along and just off the coast Saturday.
There is some potential instability and at 55 knots 2000 feet
above ground level. LLWS is a concern again near KOTH and perhaps
some inland valleys. Outflows from heavier showers or weak
thunderstorms could produce gusts to 60 mph along coastal areas.

Overall, VFR will prevail through the TAF period with higher
ceilings in this chaotic weather, although MVFR ceilings are
possible with some IFR visibilities under heavier showers.

-Smith

&&

.MARINE...Updated 200 PM PST Friday, January 2, 2026...Conditions
will worsen across the waters tonight with gales and very steep seas
beyond 10 NM this evening gradually expanding to the inner waters
overnight into Saturday morning.

Widespread gales are expected Saturday through Saturday night with
very steep seas peaking near or just above 20 feet dominated by very
steep wind waves and south fresh swell. Breezy conditions with steep
to very steep seas linger into Sunday with conditions gradually
improving Monday into Tuesday with a mix of northwest swell and
lingering fresh south swell. -Spilde

&&

.COASTAL FLOODING...Updated 200 PM PST Friday, January 2, 2026...
High astronomical tides and storm systems offshore the next couple
of 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 tide (1-2 hours before and
after) Saturday morning into early Saturday afternoon. This could
occur again during Sunday morning's high tide, but will be evaluated
for potential extension in the next couple of shifts. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 10 AM PST Saturday for ORZ026-029>031.

     High Wind Warning from 10 AM Saturday to 4 AM PST Sunday for
     ORZ022.

     Coastal Flood Advisory until 1 PM PST Saturday for ORZ021.

     Winter Weather Advisory from 4 PM Saturday to 1 PM PST Sunday
     for ORZ027.

CA...Winter Storm Warning from 4 PM Saturday to 4 PM PST Sunday for
     CAZ080-082-083.

     Wind Advisory until 10 AM PST Saturday for CAZ081-084-085.

     High Wind Warning from 10 AM Saturday to 4 AM PST Sunday 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.

&&