396
FXUS66 KMFR 032305
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
305 PM PST Sat Jan 3 2026

.DISCUSSION...Activity around a low pressure system remains a
guiding influence in weather across northern California and southern
Oregon. Another front will move over the area this afternoon and
tonight, bringing impactful rain and winds tonight into Sunday
morning. Gusty winds continue in the Shasta Valley and are returning
to the Rogue Valley. Weed airport is seeing gusts over 40 mph while
20 mph gusts are reaching the Medford airport. Showers have been
minimal today but will increase this afternoon and look to continue
into Sunday. Most precipitation will be focused on the Mount Shasta
region in Siskiyou County and across Curry county, where 1 to 2
inches of precipitation is possible through the rest of today.

Snow levels remain at 5500-6000 feet this afternoon, keeping
snowfall to higher terrain. Snow levels look to drop to 4500 feet
this evening through Sunday morning. Heavy snowfall will continue
over higher terrain in Siskiyou County, which is addressed by a
Winter Storm Watch for areas above 5000 feet in western Siskiyou
County. SPC HREF guidance has 50-90% chances for 1 inch per hour
snowfall rates around Crater Lake 3 AM and 7AM on Sunday morning,
with slightly lower rates around Diamond Lake. A Winter Weather
Advisory is in place over the Cascades from Crater Lake northward
this evening into Sunday afternoon to address expected hazardous
conditions. Gusty winds continue along the coast south of Port
Orford, in the Shasta and southern Rogue valleys, and over east
side terrain into Sunday morning but look to be below product
thresholds by the afternoon.

On Monday, the upper trough splits as a cutoff low travels to the
south and the remnants of the trough pass over the area. This will
allow for one last push of precipitation across the area. Snow levels
may reach 3500 feet in areas by Monday night. The Winter Storm
Warning for Siskiyou County terrain remains in place into Monday
evening, but other areas will not see the accumulation necessary for
hazard products. Snowfall continues over the Cascades through Monday
evening. Some snow showers may reach I-5 near Sikiyou Summit or
between Weed and Dunsmuir as well as Highway 89 south of Mount
Shasta on Monday morning, but substantial accumulation is not
expected in these areas. Lower elevation areas will see light to
moderate rainfall on Monday.

Activity pauses briefly on Tuesday morning before a cold front moves
towards the area over the Pacific. Precipitation returns by Tuesday
afternoon and could continue into Thursday morning. Initial snow
levels of 4000 feet could drop to 2000-2500 feet by Thursday
morning. Current guidance would have Advisory-level snowfall around
Crater Lake and Diamond Lake, with periods nearing Warning
thresholds. Between Tuesday evening and Thursday afternoon, 8 to 16
inches of snowfall is forecast over the Cascades between 4500 and
5500 feet, with up to 24 inches possible over higher peaks and
ridgelines. Willamette Pass may also see over a foot of snowfall,
with 4 to 8 inches reaching Chemult and Chiloquin. I-5 at Siskiyou
Summit and between Weed and Dunsmuir may also see 1 to 4 inches of
snow as a preliminary forecast. Terrain in Siskiyou County could see
up to a foot of snowfall. Other areas would see light to moderate
rainfall or light snowfall.

Beyond Thursday afternoon, a stable period under a Pacific ridge
remains the overall expectation. While GFS meteogram guidance still
wants to keep some chances for activity into next weekend, EC
meteograms and deterministic imagery for both models is trending
towards a period of upper level ridging after the Tuesday-
Thursday front. -TAD


&&

.AVIATION...03/18Z TAFs...Updated 22Z...Southwest to west winds
surfaced at Medford this afternoon as frontal rain band moved
through with evaporative cooling and downward transport leading to
wind gust of ~30kt at the airport. Wind speed and direction is
tricky through this evening though as showers may erode and
southerly to southeast wind could resume before subsiding later
tonight. We think wind gusts at the airport stay just below criteria
(35 kt) for airport weather warning, so will continue to hold off
and monitor. However, at Klamath Falls, peak wind gusts should
be 35 kt or higher, so an airport weather warning is in effect there
until 1 am PST. Conditions are mostly a mix of VFR/MVFR currently
with areas of higher terrain obscuration in showers, but local IFR
is occurring in the Mt. Shasta region where upslope flow is
enhancing precipitation near the mountain. Isolated thunderstorms
are still possible over the coastal waters and along the
immediate coast into this evening, which could cause strong
wind gusts in excess of 40 kt. With winds subsiding later tonight,
this will allow for lowering ceilings and more widespread MVFR/IFR
conditions. -Spilde


&&

.MARINE...Updated 200 PM PST Saturday, January 3, 2026...Gales and
very steep seas peaking near 20 feet dominated by very steep wind
waves and south fresh swell continue in all waters through
early Sunday morning. Isolated thunderstorms could occur into this
evening. Steep to very steep seas linger during Sunday with
conditions gradually improving Monday into Tuesday with a mix of
northwest swell and lingering fresh south swell. Early indications
are for a long period swell to arrive over the waters Tuesday
night and become high and steep Wednesday into Thursday. -Spilde

&&

.BEACH HAZARDS/HIGH SURF...Updated 200 PM PST Saturday, January 3,
2026...Long period swell is forecast to arrive over the marine
waters Tuesday night, then build Wednesday into Thursday.
Early indications are showing the swell arriving at 3-6
feet at 20-25 seconds, which initially poses a risk for sneaker
waves Tuesday night into Wednesday. Then, as the swell builds to 13-
18 feet, high surf risk increases Wednesday afternoon. It`s
still several days away, so we`ll continue to monitor for possible
beach hazard and/or high surf products. -Spilde

&&

.COASTAL FLOODING...Updated 200 PM PST Saturday, January 3, 2026...
Reports of minor flooding on roadways associated with tidal
overflow (high astronomical tides and storm surge) were received
from city officials in Coos Bay during this morning`s high tide.
As such, we decided to issue another coastal flood advisory for
Sunday`s high tide (2 hours before and after), which occurs at 1204
PM PST. -Spilde


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Warning until 4 AM PST Sunday for ORZ022.

     Wind Advisory until 7 AM PST Sunday for ORZ026-029>031.

     Coastal Flood Advisory from 10 AM to 2 PM PST Sunday for ORZ021.

     Winter Weather Advisory until 1 PM PST Sunday for ORZ027.

CA...Winter Storm Warning until 4 PM PST Monday for CAZ080-082-083.

     High Wind Warning until 4 AM PST Sunday for CAZ081.

     Wind Advisory until 7 AM PST Sunday for CAZ084-085.

PACIFIC COASTAL WATERS...Gale Warning until 7 AM PST Sunday for
     PZZ350-356-370-376.

     Hazardous Seas Warning from 7 AM to 10 PM PST Sunday for PZZ350-
     356-370-376.

&&

$$