893
FXUS66 KEKA 100820
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1220 AM PST Wed Dec 10 2025

.SYNOPSIS...


&&

.DISCUSSION...Satellite imagery shows areas of stratus and fog in
many of the coastal and interior valleys late this morning. Low
cloud cover will gradually lift and scatter out today, giving way
to a fairly pleasant December afternoon. The main exception will
be at the northern Humboldt and Del Norte coasts, where stratus
and drizzle is likely to return this afternoon and evening one
last day. Precipitation amounts are very minimal with up to a few
hundredths of an inch of drizzle possible in Del Norte. High
pressure moving over the area will disrupt any further drizzle
after today.

The persistent ridge of high pressure responsible for blocking
Pacific storm systems will strengthen and nose eastward through
the week. Significant warming for the interior will occur as a
result. The current forecast yields interior high temperatures
reaching 10-20F above climatological norms midweek through the
weekend. NBM shows a high probability (70% or higher) for the
warmer interior valleys, including Ukiah and much of Lake County,
to exceed 70F Thursday and Friday. NBM probabilities for
exceeding 75F around Ukiah is around 20% for Thursday and Friday.
This would break the high temperature record of 72F from 1958 for
Ukiah on Friday if the forecast holds. NBM data shows around a 40%
chance of a new record for Friday.

Ensembles and clusters are hinting at the weakening of the
stubborn ridge through the weekend. Precipitation chances start to
increase through the latter portion of the weekend. However, any
meaningful breakdown of the ridge or zonal flow may not occur
until early next week. A more likely situation is fairly steady
light rain compared to heavy downpours.


&&

.AVIATION...(06Z TAFs)...Ceilings have come down as of 04z for
KCEC as IFR conditions are likely to prevail until Wednesday
afternoon. With light drizzle, accumulated precipitation presents
another hazard as radiational cooling produces fog at ground level.
Tempo groups for such the occasion accompany the 06z TAFs. Light
wind is an additional supporting factor for fog development which is
in play for all terminals through the night. Ceilings at KCEC will
hover under 1000ft or so, with lower visibility into Wednesday
morning. KACV has similar conditions, lifting ceilings out by 18z
Wednesday.  KUKI is also susceptible to fog from a different source,
likely to be advection from a cardinal direction. The area profiler
shows shallow fog south of KUKI, so not likely to advect up the
valley but possible from other directions. /EYS


&&

.MARINE...Northerly winds are forecast to ramp up south of Cape
Mendocino and persist through at least Friday. Wind gusts peak
around 20-30 kts in the lee of Cape Mendocino, with breezy winds
reaching nearshore areas at times. Steep wind waves of 5-7 ft are
possible with these winds. North of Cape Mendocino, winds remain
light and southerly through at least Thursday. North winds return
late Thursday into Friday and could be breezy in the outer waters.
The sea state remains dominated by mid-period northwest swells, with
additional swells filling in Wednesday and again Thursday. These
will keep the sea state elevated and combined seas could exceed 10
ft at times, especially south of the Cape where the swell will
combine with the steep wind waves. Winds ease this weekend as high
pressure weakens. JB


&&

.BEACH HAZARDS...An increased threat of sneaker waves is expected
for the Del Norte, Humboldt, and Mendocino coastlines this Thursday.
A mid-period westerly swell generated by a storm currently located
near 45N,155W will enter the coastal waters early Thursday
(tomorrow) morning. A lack of local wind waves along the North
Coast will allow this swell to dominate the sea state over an
existing, yet decaying, swell, creating beach conditions that
could look deceivingly calm. Forecast confidence will grow as the
swell passes NOAA/NDBC buoys Wednesday morning. Remember to never
turn your back to the ocean, and to avoid steep beaches, jetties,
outcroppings, and rocks during these events. DS


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement from Thursday morning through
     Thursday evening for CAZ101-103-104-109.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 PM this afternoon to 10 AM PST
     Thursday for PZZ455.

     Small Craft Advisory from 3 PM this afternoon to 2 AM PST
     Friday for PZZ475.

&&

$$

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

Visit us at https://www.weather.gov/eureka

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

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