Klamath River, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

378
FXUS66 KMFR 232233
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
233 PM PST Tue Dec 23 2025

.SYNOPSIS...A deepening trough over the eastern Pacific will be the
persistent weather player this week, sending two impactful systems
into the region this week. A quick moving surface low will
strengthen inside 130W tonight as it moves south to north along the
Oregon Coast through Wednesday morning. After a relative lull in the
weather Wednesday afternoon, another surface low will strengthen
just inside of 130 W, but remain farther offshore compared to the
first. This second low pressure will linger offshore through the day
Thursday (Christmas), then finally move westward Thursday night into
Friday morning. Once this trough and surface system push to the east
late Friday into early Saturday, upper level ridging will nudge into
the region and persist through at least mid-week next week.

&&

Key Points:

 *Impactful weather expected through the Christmas Holiday, with a
  brief lull between systems expected during the day Wednesday.
 *Widespread strong winds expected tonight into Wednesday
  morning, with another round expected Wednesday night through
  Thursday.
 *Strongest winds expected tonight into Wednesday
 *High snow levels through Wednesday morning (6000-7000 ft),
  lowering Wednesday afternoon through Thursday (4500 ft).
 *Moderate to heavy snow expected across northern California
  Wednesday through Thursday night.

.SHORT TERM (through Friday morning)...A one-two punch pattern
will impact the region tonight into Wednesday morning and again
Wednesday night through Thursday. The two main impacts from these
fronts will strong winds and moderate to heavy precipitation with
snow above 4500 ft and rain below.

First the winds: There is still some degree of uncertainty regarding
the path of the offshore compact surface low tonight into Wednesday,
and this will have a significant impact on the wind forecast. The
most likely solution (favored by the bulk of model solutions,
including the GEFS, NAM, and high resolution models) takes the low
up the coast just offshore of southern Oregon. This scenario
produces MSLP gradients of -10 to -15 across the area and southerly
mid level winds in excess of 85 kt. This translates to significant
wind impacts for most of the area, with strong gusty winds reaching
nearly all of southern Oregon and far northern California. A
gradient of -8 is all that is typically needed for a High Wind
Warning at the coast (with gusts of 70 mph to potentially as high as
100 mph along the coastal headlands), and for many locations inland
such as the Shasta Valley and across the East Side where gusts could
easily approach 60 to 70 mph, especially if precipitation helps to
drag winds down closer to the surface. With this storm track as the
most likely scenario, and with the Christmas holiday just around the
corner, have issued several High Wind Warnings and Advisories.
Details on these can be found at PDXNPWMFR.

The next most likely scenario, but less likely than the first
(favored by the majority of the EC ensemble members) brings the
surface low onshore to our south, which cuts the coast and much of
the West Side off from the stronger winds. Conditions would still be
quite breezy in those locations, while the East Side, Shasta Valley,
and high terrain would still be under the threat of the same strong
gusty winds. Therefore, overall confidence in the official forecast
and the high wind headlines is much higher generally along and east
of the Cascades than it is to the west.

Another scenario worth mentioning is the potential for very strong
winds Wednesday morning into early afternoon.  A "stinger" jet
wrapping around the back side of the low could impact areas along
the coast and coastal mountains on the back side of the low as it
slides north Wednesday morning, producing a quick burst of sustained
west winds that could exceed 60 mph with hurricane force gusts.
There is a low chance this occurs, roughly 5 to 10%, but if it does,
significant impacts would result, with downed trees, damaged power
lines, and potential structure damage.

Winds diminish Wednesday evening into Wednesday night, then another
storm approaches the area Christmas Day. The low looks to remain
farther offshore, but lingers a bit longer than the previous one,
with MSLP gradients much weaker (-1 to -5), and mid-level winds
still strong but weaker than the previous system. That being said,
this storm could still be significant in its own right, and current
thinking is that wind headlines may be needed in the Shasta Valley
and southern Rogue Valley, where winds better align with the
terrain, and across the East Side where mid level winds are
strongest. Have held off on issuing any new warnings or advisories
with this event to prevent any confusion with this first storm, and
to allow confidence to improve across the model solutions. Updates
are likely over the next 24 hours. -BPN

Precipitation/Snow: Snow levels are currently rising from east to
west today as a front lifts north and west. Snow levels will hover
around 6000-7000 ft through tonight, so we don`t anticipate any
winter impacts aside from the highest peaks as the first front moves
through the region by late Wednesday morning. Snow levels lower to
around 4500-5000 ft behind the front late Wednesday morning and
hover at those levels through Thursday morning. Meanwhile a second
front pushes into the region later in the day Wednesday and persists
through the day Thursday. Since these will be southerly flow
systems, the heaviest rain/snow will be focused south of the OR/CA
border and into the Curry County mountains.

As for precipitation totals, 1 to 2 inches is expected along the
coast and across western/southern Siskiyou County through Wednesday
morning, with generally 0.25-0.50" along the Cascades and west of
the I-5 corridor. Downsloping winds will limit precipitation amounts
here in the Rogue Valley and across the northeastern areas. For the
second front, similar amounts are expected, with the higher amounts
focused a little farther south. While there may be some ponding on
roadways during periods of heavy rain, all river forecasts currently
remain below flood stage and even remain below action stage.

As for snowfall, moderate to heavy snow is expected across northern
California Wednesday evening through Thursday for elevations above
4500 ft. By the time Friday morning arrives, 1 to 3 feet of snow is
expected across the Klamath mountains of Siskiyou County as well as
the Warners of Modoc County. Winter Storm Warnings remain in effect
for this, and details can be found at WSWMFR. Given the southerly
flow nature of the second system and lower snow levels, upslope flow
is expected to be enhanced in the Mt Shasta City region, which is
likely to lower snow levels down to 3500 ft later Wednesday through
Thursday. This will bring some winter impacts to the Interstate 5
corridor over the holiday with 6 to 12 inches expected in that
region. We did include this area in the winter storm warning for
both strong winds and moderate snow. Farther north to the Cascades,
we opted to cancel the Winter Weather Advisory in favor of a High
Wind Warning. The southerly flow nature of this system doesn`t favor
high snow amounts for the Cascades, and we felt that strong winds
would be the higher impact there. The heaviest snow/precipitation is
expected Wednesday night into Thursday, then winding down Friday
while snow levels lower to 3500ft.

.LONG TERM (Friday through Tuesday morning)...The upper trough
will move through the region Friday, and precipitation will
continue into early Saturday. Snow levels will hover around 3500
ft during this time, resulting in some light snow across the East
Side and continued snow (but lighter amounts/intensity) in the Mt
Shasta region.

Once this system exits out of the area by Saturday, high pressure
will nudge in from the eastern Pacific and bring dry conditions
through at least Wednesday of next week. Expect persistent valley
fog during this pattern with plenty of sunshine and warmer
temperatures in the mountains. Active weather could return towards
the end of next week, /BR-y

&&

.AVIATION...23/18Z TAFs...Some lighter rain is producing lower
ceilings in the valleys this afternoon with MVFR and IFR ceilings
across locations west of the Cascades. These lower ceilings will
likely continue through the TAF period. East of the Cascades VFR
ceilings will prevail through the TAF period.

Gusty winds are a big concern at the end of this TAF cycle as a low
strengthens off the California and Oregon coastline as it vectors to
the north. With the potential of stable air in the valleys tonight,
wind shear will show up over Medford(KMFR) and Roseburg(KRBG) later
tonight and early Wednesday morning. Those stronger winds will
likely mix down to the surface at some point in the morning hours
with gusts greater than 35 kts at KMFR and Klamath Falls(KLMT).
-Smith

&&

.MARINE...Updated 200 PM PST Tuesday, December 23, 2025...Two
potentially significant storm systems will impact the area through
Christmas. The first, quick-moving system, arrives late Tuesday
through Wednesday morning and the second, slower-moving system,
arrives late Wednesday night and persists into Friday morning.

There is STILL quite a range in solutions (and therefore, low
confidence) for the first system as it moves south to north along
the coast. This brings a wide range of possible scenarios in terms
of wind strength over the marine waters since the position of the
low is uncertain. Most of the guidance maintains that the low will
run up the coast just offshore, producing strong gale force winds
and very steep seas. This is the most likely scenario and is what
the official forecast reflects. Two other scenarios, which lie
closer to the extremes (on both ends) are possible, however.
Stronger model solutions (about a 20-30% chance) show a period of
southerly storm force winds occurring during the early morning hours
Wednesday, that quickly shift the west in the late afternoon as
winds wrap around the back side of the low. Weaker solutions
(similar %) move the low into Cape Mendocino and keep the strongest
winds to our south. With crab season well underway, and given the
upcoming holiday, have erred on the side of caution and issued a
Gale Warning, mentioning the potential for storm force gusts.

The second system remains farther offshore on Thursday and lingers
over a longer period of time into Friday morning. Confidence is
higher regarding some details with this system as guidance is in
better agreement, but another round of gales is likely with this
storm. Both systems will also bring a round of very steep and
hazardous seas and potentially hazardous bar crossings. Winds will
gradually ease late Friday, but seas are likely to remain steep into
early Saturday. Once the Christmas system moves out of the region,
the overall weather pattern looks to settle down over the weekend,
possibly into next week, and conditions will improve overall with
light to moderate north winds. -BPN/BR-y/Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Warning from 10 PM this evening to 1 PM PST Wednesday
     for ORZ021-022-025>031.

     Wind Advisory from 10 PM this evening to 1 PM PST Wednesday for
     ORZ023-024-026.

CA...Winter Storm Warning until 10 AM PST Friday for CAZ080-082>085.

     High Wind Warning from 10 PM this evening to 1 PM PST Wednesday
     for CAZ081-084-085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST this
     evening for PZZ350-356-370-376.

     Gale Warning from 10 PM this evening to 10 PM PST Thursday for
     PZZ350-356-370-376.

&&

$$

MNF/BPN/CZS