Arcata, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

849
FXUS66 KEKA 142129
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
229 PM PDT Tue Oct 14 2025

.SYNOPSIS...Cool and moist conditions will persist across the area
through Wednesday with slight warming and drying into the weekend.
Another rain event is most likely around Sunday.


&&

.DISCUSSION...Very light rain showers have persisted
across southern Mendocino and Lake Counties through the day as low
pressure gradually makes landfall along the southern California
coast. Overall rainfall has generally stayed below 0.2 inches with
little more expected through the evening tonight. Otherwise, the
cold and moist airmass has kept temperatures cool in the low 60s and
upper 50s despite clearing skies.

Heading into tonight, still elevated dewpoints will likely aid in
continued valley fog formation. Despite generally clear skies,
dewpoints solidly above 40 will most likely inhibit frost formation
all but the coldest valleys. The most likely locations for some
patchy frost tonight will be around Ruth Lake and in Hayfork. THe
potential for frost will slightly increase Wednesday night as slight
drying is expected. Even slightly more drying than forecast,
however, could greatly increase the potential for frost and will
need to be watched closely.

Conditions will only gradually ease late in the week as a weak lobe
of high pressure build across the area, though persistent northerly
wind and short days will limit the magnitude of warming. By Friday,
the warmest interior valleys will likely reach into the low 80s with
most areas closer to the mid 70s. Moderate marine influence will
likely keep coastal conditions not much warmer than the upper 60s
even though light offshore flow will promote generally clear skies
during the day. Otherwise winds will be weak.

Another round of rain is most likely to impact the area around
Sunday into early next week. Deterministic models mostly resolve a
shallow trough which would mostly restrict rain just to the
immediate North Coast. 90% of ensemble members show at least light
wetting rain. The spread of ensembles resolves 2 distinct scenarios.
About 50% show a light rain even with total precipitation of only
0.5 to 1.5 inches along the coast, while 40% show a stronger though
still moderate event with rainfall of 2 to 3 inches. The stronger
scenario would show some slight potential for southerly wind gusts
up to around 40 mph in exposed areas. /JHW


&&

.AVIATION...The upper level low to the south of the area is bringing
some clouds and few showers to southern Mendocino and Lake counties,
however conditions continue to be mainly VFR. Tonight offshore flow
is expected to persist in the evening. Overnight southerly flow near
the coast is expected to push some stratus north. Models are
indicating this may reach KACV and KCEC around sunrise on Wednesday,
however confidence is low on this. If stratus does make it up the
coast this may remain cloudy for portions of the day. MKK


&&

.MARINE...Northerly winds are in place across the waters this
afternoon. Wind driven waves are expected to peak around 5 to 7 feet
this evening. These will combine with a northwest swell around 10
seconds. This two waves are expected to combine and peak around 7 to
10 feet this evening. In addition there is a 17 second swell, but
these is only expected to peak around 4 feet.

Tonight these winds start to weaken and the stronger winds move
offshore. This will allow southerly winds advance north along the
coast. These will continue on Wednesday. Some of these winds may be
briefly around 15 kt.  The long period swell continues around 3 feet
at 15 seconds. The northwest 10 second northwest swell continues to
be around 4 feet at 15 seconds.

Wednesday night into Thursday northerly winds return and these are
expected to be stronger. These winds are expected to peak on Friday
and diminish through the day into Saturday. There may be some local
gale force gusts, especially south of Cape Mendocino. A larger
northwest wave is expected to build in on Friday evening. This is
expected to peak on Friday around 9 feet at 15 seconds. Saturday
night into Sunday morning there may be some brief southerly winds as
a cold front swings through. The strength and timing remain
uncertain, but most models keep the winds below 20 kt. Northerly
winds are expected to quickly return Sunday afternoon or overnight.
MKK


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT this afternoon for
     PZZ455.

     Small Craft Advisory until 11 AM PDT Wednesday for PZZ470-
     475.

&&

$$

NOTE: The full forecast discussion is now regularly issued between
10 am/pm and 1 pm/am. Additional updates will be issued as needed.

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png