414
FXUS66 KEKA 211402
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
428 AM PST Fri Feb 21 2025

.SYNOPSIS...Dry and warmer weather continues today. Chance of
rain returns this weekend and continues into early next week.
Gusty southerly winds expected along the North Coast and over the
interior mountains this weekend and early next week.

&&

.DISCUSSION...Satellite imagery showed variable high thin clouds
moving across the area this morning. Patches of fog and low cloud
cover were also apparent underneath the cirrostratus. More high
and perhaps mid clouds offshore will likely spread over the area
through today. Ridge aloft will dominate and no rain is expected.
Even tonight high resolution model guidance continues to indicate
very little or no rain for the area, though CAMS show a few light
showers or sprinkles possible tonight.

A long fetch of deep layer moisture emanating from the subtropics
(PWATS over 1 inch) will get ingested into a frontal system that
will approach the west coast on Saturday. The front will most
likely stall offshore or just to the north of the ORCA border with
episodic warm fronts producing bouts of moderate to locally heavy
rain across Del Norte County and far northern Humboldt. Brunt of
this atmospheric river will be aimed north of the area with Del
Norte on the southern edge of the IVT plume max (AR1-AR2 with
lower probabilities for AR3). Expect mostly beneficial rainfall.
Minor nuisance flooding is possible with the heavier rainfall
Saturday night into early Sunday. Mudslides will also be possible
in the steep terrain on highway 199 in Del Norte County Saturday
night when the heaviest rain rates occur.

Otherwise, expect mild temperatures with a chance for light rain
for the remainder of the area during the weekend. Gusty winds will
also occur with this stationary boundary and minor impacts are possible
especially over the coastal headlands. A surface low is forecast
to develop just outside 135W north of 40N on Monday and stronger
wind gusts to 50 mph are possible for the coastal headlands and
interior ridges as the pressure gradient tightens and a 925mb
southerly 50kt+ speed max develops along the coast in advance of
a frontal boundary. The exact timing remains uncertain, though the
ECMWF has been clustering around Monday afternoon/evening with
ensemble mean gusts near 50 mph for Pt St George and KCEC airport.
Looking at the NBM, 90th percentile max gusts are on the order of 55
to 65 mph over the interior mountains of Del Norte with lower
probabilities for gusts over 50 mph for the Humboldt interior
mountains; Kneeland and Berry Summit. Wind this strong will make
driving difficult and could knock down tree branches.

Precip should start to end on Tue as broad upper ridging quickly
springs back and holds into mid week (Wed). The ridge aloft with
above normal 500mb heights will likely remain the dominant feature
controlling NW California weather into late next week. Temperatures
will likely remain above normal. DB

&&

.AVIATION...Offshore flow has kept VFR conditions at the terminals,
with low cloud constrained to some of the river valleys early this
morning. Some brief impacts from shallow mist/fog is possible at all
the terminals before/around sunrise, but confidence is low. Any low
cloud that does form will lift and scatter out shortly after
sunrise. HREF is hinting at stratus forming offshore this afternoon,
and onshore flow could push this into the coastal terminals. A weak
shortwave could bring a brief sprinkle to CEC this evening, as well.
While confidence is not high on seeing stratus (less than 30% probabilities).
If any does push on shore, the shortwave could weaken the surface
inversion to result in IFR/MVFR ceilings rather than LIFR. Regardless,
rain chances increase tonight into Saturday. JB

&&

.MARINE...Relatively light westerly winds are expected today as high
pressure weakens, but seas remain elevated as a fresh long-period
westerly swell builds in, bringing combined seas of 8-12 ft. Winds
turn southerly ahead of a front overnight into Saturday. Significant
increases in winds are expected north of Cape Mendocino, with strong
breezes to near-gale force gusts forecast Saturday afternoon. South
of Cape Mendocino, winds remain relatively light Saturday with
gentle to moderate breezes expected.

Winds Sunday remain elevated in the northern waters and increase
slightly in the southern waters to moderate to fresh breezes. Near-
gale force gusts are possible in the northern waters again Sunday
afternoon. Seas through the weekend will be characterized by
southerly wind waves and further long-period westerly swells. Winds
further increase Monday as a front moves through, with gales
possible north of Cape Mendocino. JB

&&

.BEACH HAZARDS...A westerly swell peaking around 9-12 ft at 16
seconds builds into the waters today. With light winds and mild
weather expected, beachgoers should be cautious as this swell
presents a moderate sneaker wave threat. Be cautious visiting steep
beaches and jetties and remember to never turn your back on the
ocean. JB

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement through late tonight for CAZ101-103-
     104-109.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from midnight tonight to 3 PM PST
     Sunday for PZZ450.

     Small Craft Advisory from midnight tonight to 3 PM PST
     Saturday for PZZ455.

     Small Craft Advisory from 3 PM this afternoon to 3 PM PST
     Sunday for PZZ470.

     Small Craft Advisory from 3 PM this afternoon to 3 PM PST
     Saturday for PZZ475.

&&

$$

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