656
FXUS66 KEKA 162157
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
257 PM PDT Fri May 16 2025

.SYNOPSIS...Tonight and Saturday a weak weather system will
increase cloud cover and bring some light showers or drizzle to
Humboldt and Del Norte counties and widespread clouds. Breezy
northwest winds are anticipated each afternoon with increased
strength Saturday and Sunday. A warming trend is expected next
week.

&&

.DISCUSSION...A weak weather system moved by last night and helped
to weaken the inversion and keep coastal clouds more limited than
in previous days. The next shortwave starts to approach the area
this afternoon and is expected to increase stratus coverage and
deepen the mariner layer overnight. Drizzle is likely along the
coast tonight and Saturday morning. This is expected to be limited
to the coastal areas in Humboldt and Del Norte counties. NBM model
probabilities of over 0.10 inches of rain are only around 20
percent in interior Del Norte county with lower amounts elsewhere.
Winds are also expected to increase behind this weather system
both Saturday and Sunday afternoons. Gusts of 25 to 35 mph are
likely along the coast and over exposed areas. Sunday winds will
start to diminish in the inland areas while the coast will remain
nearly as windy. Highs over the weekend are generally expected to
be in the 60s to low 70s in the inland areas. Most areas are
expected to warm a few degrees on Sunday. The coldest night is
expected to be Sunday morning with frost possible in the colder
valleys of Trinity county, northeast Mendocino county and
northern Lake county. The cloud cover still could keep some of
these areas warmer, but this is uncertain at this point.

Next week warmer and drier conditions are expected across the
area, however the high pressure looks slightly weaker than it did
on earlier runs with some shortwaves moving by to the north of the
area Monday through Wednesday. It still looks like all the rain
will remain north of the area. Some mid or clouds are possible
with these systems and they may allow coastal clouds to develop as
well. In general it looks like temperatures will warm each day
through Wednesday with some cooling possible later in the week.
MKK

&&

.AVIATION...Conditions have improved to VFR at all terminals
early this afternoon as low clouds have largely scattered out.
Northwesterly breezes at the coastal terminals are expected to ease
this evening and overnight. Model guidance is trending toward a
shallow marine layer forming this evening and impacting the coastal
terminals with MVFR/IFR ceilings dropping to IFR/LIFR later in the
evening. This would correspond with a weak front moving through late
this evening into early tomorrow morning, which could bring a brief
period of lower ceilings and visibilities with light rain and
drizzle. The marine layer is forecast to deepen behind the front,
which may improve conditions to MVFR or IFR ceilings by sunrise.

In UKI, VFR is forecast for the next 24 hours. Northwesterly winds
will increase tonight, though it is uncertain if these will mix down
to the surface. Regardless, LLWS will be a threat tonight as 30-35
kt winds are forecast 1500-2000 AGL. These winds combined with a
deeper marine layer could push stratus into/above UKI, though
uncertainty is high. If any does make it, MVFR ceilings are
possible. Any ceilings are expected to lift and scatter out after
sunrise. JB


&&

.MARINE...Northerly winds have eased north of Cape Mendocino as a
weak low pressure approaches the area. Elevated winds of 25-30 kts
are possible in the lee of Cape Mendocino this afternoon with steep
wind waves of 6-7 ft. Winds and seas ease tonight, but only
temporarily as northerly winds increase again behind the front
Saturday morning. Near-gale force gusts are possible in the lee of
the Cape Saturday afternoon into Sunday. Fresh to strong breezes are
forecast north of Cape Mendocino. Northerlies ease slightly Monday
as the pressure gradient weakens, especially north of Cape
Mendocino. JB


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT Saturday for PZZ455-475.

&&

$$

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