731
FXUS66 KMFR 072345
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
345 PM PST Fri Feb 7 2025

.Update AVIATION Discussion...

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.AVIATION...08/00Z TAFs...Scattered rain and snow showers will
continue through this afternoon with a mix of MVFR and VFR ceilings
gradually becoming VFR in most places. Areas of higher terrain
obscuration are still expected. A break in the action this evening
could allow some fog/low clouds to develop tonight depending on
extent of mid-level cloud cover. Model soundings show fog potential
at both Medford/Klamath Falls with some clearing this evening and a
rapid drop off in temperature. We have hinted at this potential in
the TAFs, but there`s enough uncertainty to wait and see how
conditions develop this evening. The next disturbance will also be
arriving from the northwest, which will bring additional cloud cover
and at least MVFR ceilings Saturday morning. This system will be
bring some rain showers along the coast and snow showers inland
above 1000 feet. Even some wet snow could mix in at elevations down
to around 500 feet at times (Roseburg), but little to no snow
accumulations are expected for West Side Valleys. -Spilde/BR-y

&&

.PREV DISCUSSION... /Issued 302 PM PST Fri Feb 7 2025/

DISCUSSION...A few scattered showers continue over northern
California and southern Oregon this afternoon, but otherwise
activity has significantly decreased compared to the last few days.
With a cold air mass moving over the area, overnight lows will drop
across the area tonight. For Oregon counties west of the Cascades,
this drop will be 5 degrees or so from Thursday night. For areas
east of the Cascades and across Siskiyou County, this drop could be
up to 15 degrees. Siskiyou County will see overnight lows in the mid
teens to low 20s, while overnight lows east of the Cascades will
generally be in the single digits.

Another cold front will bring additional precipitation on
Saturday. With snow levels at 500 to 1500 feet, additional
snowfall is possible but forecast amounts are unimpactful. 1-2
inches of snow is possible over southern coastal ranges and over
the Cascades, with trace amounts possible in between. Southerly
winds will pick up over elevated terrain on Saturday morning
through the evening, but will not approach advisory levels.

An extended period with little to no active weather is in the
forecast for Sunday through Wednesday. Northwesterly flow behind the
front may allow for some showers to continue over the Cascades on
Sunday, and a mostly dry cold front might bring some showers over
elevated terrain on Tuesday morning. Overnight low temperatures will
be a concern throughout this period, as they continue to drop.
Lingering snow cover will minimize surface warming and areas of
clear skies will allow for radiative cooling. In areas with these
conditions, overnight lows may drop below expected values.
Alternatively, fog may develop in low-lying or sheltered areas.
Fog can actually help to hold warmth at the surface, making for
warmer overnight lows in areas with stubborn fog. Confidence is
high enough to support a Freeze Warning for areas near the Oregon
coast early Sunday morning, with additional Freeze Warnings
possible for these areas into the week. A Cold Weather Advisory is
in place for areas along and east of the Cascades as well as
Siskiyou County for Sunday night through Wednesday morning.
Although this Advisory is present during daytime hours, it solely
addresses overnight conditions. Cold Weather Advisories may also
be needed for those counties not currently included, but
temperatures for these areas are more borderline which brings less
confidence in issuing an additional Advisory. That said, all
areas will see overnight lows below freezing in this period.
Taking the proper precautions for individuals, pets and
livestock, plants and water pipes, is encouraged in this period.

On Thursday, a deepening low pressure system approaches the area
from the Pacific. While model guidance shows some variation in the
exact placement, this system looks to bring abundant moisture and
southwesterly flow. This pattern tends to bring snowfall to the
Mount Shasta area as well as other elevated terrain. While any
guidance for almost a week away is to be taken with a grain or two
of salt, forecast snow levels of 2500 to 3500 feet do look to allow
for another round of widespread snowfall in Siskiyou County as well
as over and east of the Cascades. This even will be watched closely
as it approaches, if it remains in the forecast.

Beyond Thursday, guidance suggests an atmospheric river could supply
moisture to the area. Long term meteogram guidance shows
continuing activity for North Bend, Roseburg, Medford, and Klamath
Falls. With these combined signals, there`s moderate to good
confidence in activity continuing, although how it will develop
remains to be seen. Deterministic guidance does not show any
strong forcing mechanisms, which suggests showers may be mostly
orographic (developing over elevated terrain). While activity
continues, long term snow guidance for Medford shows little chance
for valley snow beyond Thursday`s system. -TAD

MARINE...Updated 200 PM Friday, February 7, 2025...A front will
move through the area tonight into Saturday with brief gusty winds
and steep seas. Southwest winds in advance of the front tonight
shift to northwest during Saturday. Conditions improve a bit
Saturday night, but then north winds increase over the waters
Sunday with steep seas and conditions hazardous to small craft.
Strongest winds and steepest seas are likely south of Cape Blanco
and could persist through Monday. After a period of lighter winds
and lower seas, a more significant storm is possible with strong
south winds and very steep seas late Wednesday into Thursday.
-Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Cold Weather Advisory from 7 PM Sunday to 9 AM PST Wednesday for
     ORZ027>031.

     Freeze Warning from 2 AM to 9 AM PST Sunday for ORZ021-022.

CA...Cold Weather Advisory from 7 PM Sunday to 9 AM PST Wednesday for
     CAZ080>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 4 PM PST Saturday
     for PZZ350-356-370-376.

&&

$$