Grenada, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

636
FXUS66 KMFR 251151
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
351 AM PST Thu Dec 25 2025

.DISCUSSION...Active weather continues over northern California
early this morning, guided by southerly flow around a Pacific low
pressure system. Road cams have been showing periods of rainfall and
periods of snowfall in areas around Mount Shasta early this morning,
putting current snow levels at 4500-5000 feet in the area.
Roadside slush is visible on webcam around Mount Shasta City and
Snowman Summit, so local slippery conditions are possible on
roadways. Radar is showing showers traveling into parts of
southern Oregon near the California border. Gusty winds are
present over terrain, with observations from both Acorn Woman Peak
(southwestern Jackson County) and Colins Baldy (Western Siskiyou
County) showing gusts of of 50-55 mph.

This upper low will guide active weather through Christmas day
and into Friday morning. The Mount Shasta region will see constant
precipitation through this period. Curry County, western Siskiyou
County, and the Cascades will also see significant precipitation.
Other lower elevation areas will see light to moderate
precipitation. A cold air mass is expected to steadily lower snow
levels to 3500- 4000 feet by early Friday morning. For terrain in
southwestern Siskiyou County and around Mount Shasta, constant
snowfall will allow for 1 to 3 feet of snow to fall on area peaks
and ridgelines. The lowest snow levels may allow for Across the
east side, lower elevation areas could see 2 inches or less of
snowfall while terrain could see up to 6 inches. Cascades peaks
would see up to a foot of snow, while many passes could see up to
6 inches (Highway 66 will generally see less than an inch of
snowfall). A Winter Storm Warning for Siskiyou County terrain and
a Winter Weather Advisory for the Cascades are in place to help
highlight expected hazardous conditions. Please see WSWMFR for
more details.

Gusty southerly winds remain in the forecast as the low nears the
area, especially for the Oregon coast south of Port Orford as well
as the Shasta Valley. These areas may see wind gusts exceed 60 mph
this morning. Advisory-level winds are possible across lower
elevation to the west and to the east of the Cascades. NPWMFR has
additional details about expected gusty conditions today. Winds
ease across the area this evening and tonight.

The low and surrounding trough starts to weaken early Friday
morning, pushing inland and bringing one last wave of showers on
Friday afternoon. Flow aloft remains from the southwest, keeping the
most activity over Curry COunty, the Mount Shasta region, and the
Cascades. A slight rise in snow levels at this time may help to keep
snowfall off of highways in the Mount Shasta region.

Showers ease on Saturday morning and are nonexistent in guidance as
an upper ridge develops Sunday and into midweek. Long-term
deterministic guidance shows an upper trough flattening the ridge
and starting another period of possible active weather. Some
ambitious ECMWF ensemble members bring showers to North Bend on
the afternoon of December 31st, but the first day or two of 2026
looks more likely. -TAD


&&

.AVIATION...25/12Z 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 LIFR ceilings have
settled into the Umpqua Valley.

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

&&

.MARINE...Updated 400 AM PST Thursday, December 25, 2025...Another
strong system arrives today, bringing widespread and strong gales
(30-40 kt with gusts to 50 kt) along with very steep seas between
13 to 23 ft. Locally storm force gusts are possible late this
morning into the afternoon. Guidance indicates a 30-40% 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 today with
the chance for thunderstorms continuing across the waters from
Cape Blanco south tonight and Friday morning.

As the low pressure moves over the waters from west to east
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 afternoon. Very steep
seas will persist across all the waters through at least Friday
morning. Gusty north winds (20-30 mph with gusts up to 35 mph) are
expected to develop Friday afternoon and evening.

Once the low exits the region Friday night, 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. Areas of gusty north winds and steep seas are possible
south of Cape Blanco.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 1 PM PST this afternoon for ORZ023>026-
     029>031.

     High Wind Warning from 7 AM this morning to 1 PM PST this
     afternoon for ORZ022.

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

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

     Wind Advisory until 1 PM PST this afternoon for CAZ080-083>085.

     High Wind Warning from 7 AM this morning to 1 PM PST this
     afternoon for CAZ081.

PACIFIC COASTAL WATERS...Small Craft Advisory until 4 AM PST early
     this morning for PZZ350-356-370.

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

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

&&

$$