Callahan, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

124
FXUS66 KMFR 252303
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
303 PM PST Thu Dec 25 2025

.DISCUSSION...

Wind gusts really didn`t pan out today, especially in the valleys
this afternoon as weak mixing didn`t allow much momentum transfer.
However, some of our windier locations at elevation did reach wind
advisory criteria and the Shasta Valley was blustery as usual with
Montague reporting a wind gust of 59mph during the cyclogenesis
this morning.

In any case, the low is weakening and moving a bit farther to the
north and west this afternoon and winds will continue to die down
into the evening hours. Winter weather is the only remaining
concern as this low ends up rotating back into the northern
California coast by Friday morning. The biggest concern remains
south of the Shasta Valley near Mt. Shasta City. Heavy snow will
likely fall there tonight as high resolution guidance shows 6 to 8
inches on the valley floor around Mt. Shasta City up to Weed and
nothing north of Weed. The probability of 1" of snow per hour is
about 50%, and we usually see impacts when these 1" snow fall
rates persist for a few hours. Expect some delays in travel
tonight as the strong southerly winds enhance orographic lift
over this relatively cold air.

The Cascades and Siskiyou Mountains will also see some snow
accumulation once this low rotates into the forecast area later
tonight. Snowfall rates should pick up around this time with snow
levels down to 4000 feet across most of the forecast area, except
around Mt. Shasta City where snow levels will fall down to 3300
feet under the heavier snow.

Eventually, this low will weaken further and push into the
forecast area late Friday afternoon. Impacts remain moderate to
low around this time as snow continues to accumulate, although the
rates are falling off around this time, except the higher terrain
in California. Eventually by Friday night, the trough axis will
push further east and high pressure will begin to build in the
wake of this low. One has to think valley fog will be in the cards
and some of it could be thick given all the surface moisture.

Temperatures will be well below freezing Friday night
and Saturday night, so freezing fog is more likely across the
forecast area. Extreme cold on our graphical hazardous weather
outlook is only showing limited risk in these colder temperatures.
For perspective, our average low in Medford this time is 37 and
we`re forecasting lows in the mid 20`s here Saturday night, so
only 10 degrees below normal for this time of year, which isn`t
bad.

Overall, we`ll close out 2025 with fairly quiet weather. The NBM
is picking up on some probability of precipitation around the New
Year.
-Smith

&&

.AVIATION...25/18Z TAFs...VFR levels are generally present across
northern California and southern Oregon at the start of the TAF
period. Continuing rain and periodic snow showers around Mount
Shasta are causing local IFR/LIFR conditions, and a line of stronger
rain/snow showers is passing through Klamath Falls this morning.

Showers are expected to continue through the TAF period across the
area, with most of the activity over northern California. Snow
levels decreasing to 3500-4000 feet today into Friday may bring snow
showers over terrain and across the east side. Both rain and snow
showers can cause locally lower ceilings and visibilities as well
as obscure elevated terrain. Gusty winds are expected through this
afternoon, especially in the Shasta Valley and across the east side.
Low level wind shear may be present across most of the area through
this morning, then lingering over coastal areas and higher terrain
into Friday morning. -TAD/-9

&&

.MARINE...Updated 200 PM PST Thursday, December 25, 2025...South to
southeast gales (30-40 kt with gusts to 50 kt) and very steep seas
between 13 to 23 ft continue in all waters through this evening.
Locally storm force gusts are possible through this afternoon.
Guidance indicates a 35-45% chance for storm force gusts for the
waters with in 20 nm of shore between Gold Beach and Cape Blanco and
a 20% chance for storm force gusts for other areas. With this
frontal system, there is also a 20% chance for thunderstorms over
the waters through Friday morning. The highest chance will be found
south near Brookings.

As the low pressure moves east over the waters tonight and Friday
morning, expect continued areas of gales for the waters from Cape
Blanco south. Winds will shift from south to northwest as this low
moves through Friday morning. Very steep seas will persist across
all the waters through Friday morning. Gusty north winds (20-30 mph
with gusts up to 35 mph) are expected to develop Friday afternoon
and evening with steep seas in all waters through Saturday afternoon.

The overall weather pattern looks to settle down later in the
weekend and is expected to continue through early next week.
Overall light to moderate north winds will be found with areas of
gusty north winds and steep seas south of Cape Blanco.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 4 PM PST this afternoon for ORZ023>026-
     029>031.

     Winter Weather Advisory until 10 PM PST Friday for ORZ027-028.

CA...Winter Storm Warning until 4 PM PST Friday for CAZ080-082-083-
     085.

     Wind Advisory until 4 PM PST this afternoon for CAZ080-081-
     083>085.

PACIFIC COASTAL WATERS...Gale Warning until 10 AM PST Friday for
     PZZ350-356-370-376.

     Small Craft Advisory from 10 AM to 10 PM PST Friday for PZZ350-
     356-370-376.

     Hazardous Seas Warning from 10 PM this evening to 10 AM PST
     Friday for PZZ350-370.

&&

$$