345
FXUS66 KEKA 202306
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
306 PM PST Thu Nov 20 2025

.SYNOPSIS...Showers will dissipate this evening with cold
temperatures overnight. COnditions will quickly warm and dry into
the weekend with light drizzle along the coast early next week.


&&

.DISCUSSION...Showers have continued to cross the area
this afternoon, but have become increasingly weak as colder and
drier air pulls onshore. Showers will continue to weaken tonight
with little chance (less than 10%) of additional wetting rain
anywhere.

Recent rain has left generally moist conditions across the
area, but colder and dry air advecting over the interior has already
allowed for some interior valleys to see dewpoints drop below 38
this afternoon.More offshore flow overnight combined with drier air
may allow for patchy frost formation in interior valleys. That said,
recent rain and moisture may form fog reducing frost formation.
Chance for frost is greatest in Trinity County where few showers
have made it over throughout the the day. Closer to the coast,
unstable conditions will make any marine layer formation unlikely.

Cold air will quickly be pulled east of the area with high pressure
and offshore flow generating quick warming and drying Friday into
the weekend. By Saturday, interior highs will generally return to
the mid 60s. Dry conditions may allow for frost concerns to persist
through Saturday morning, put the chance of proper freeze conditions
remains low (less than 20%). Offshore flow Saturday will likely also
help keep the coast clear but winds turning more onshore by Sunday
will likely promote some coastal stratus formation.

Most ensemble members show a weak trough moving onshore well north
of the area early next week. That said, most members show light
rain and drizzle along the North Coast with a 90% chance of at least
trace rain amounts in Crescent City, though a less than 10% chance
of any amounts over 0.3 inches. Down in Humboldt bay there is a 45%
chance of no rain at all and less than 10% chance of even wetting
rain. High pressure will then again most likely briefly build with
about 70% of ensemble members showing another cold, cutoff low storm
system late next week. /JHW


&&

.AVIATION...(18Z TAFs)...Light rain showers will ease into the
evening as the backside of the passing front continues south of the
terminals. Ceilings around 6000-7000 feet with BKN and OVC lasting
through the evening TAF period. Southerly winds at KCEC will likely
switch to northerly by the late afternoon and NE overnight with KACV
showing northerly and easterly components before sunset. The lack of
cloud cover overnight into Friday early morning could produce ground
fog, stay tuned for further notice via TAF. Stout northerly winds
this afternoon at KUKI are possible for a few hours but will ease
after sunset. /EYS


&&

.MARINE...Winds over the coastal waters will continue to diminish.
As of 22z, winds are southerly near buoy 46027 at St.Georges,
easterly at buoy 46022-Eel River, and northerly near Pt. Arena. A
northerly flow will eventually become the ruling cardinal direction
as geostrophic flow follows the meridional isobaric set up with the
low pressure system coming inland and south of the area.

Otherwise, A large W-NW swell will begin to build and reach 15-17
feet at 13-15 seconds by the late afternoon and evening. This swell
may combine with short period wind waves and seas will once again
become quite hazardous. The Watch- SE.A, for hazardous seas has been
upgraded to a Warning- SE.W for all area waters through Friday at
17z. For the remainder of the week, northerly winds and steep wind
waves are generally forecast to prevail. Near gale wind gusts are
certainly possible downwind of Cape Mendocino. Another large W-NW
swell group will propagate into the waters this weekend and may pose
a threat for sneaker waves once the shorter period wave groups
subside.


&&

.BEACH HAZARDS...A large W-NW swell will bring a risk for dangerous
surf Thursday afternoon through Friday morning. Breakers from 16 to
20 feet are expected assuming an ideal and average beach profile.
Larger breakers will be possible if the swell ends up coming bigger
than forecast by GFSwaves. Continuing to call attention to this risk
via weather story post and on social media. The swell is too large
for sneaker wave criteria and too low to warrant a high surf
advisory. A longer period W-NW swell group from 8-12 ft with
dominant periods near 16 seconds is forecast to build over the
weekend. This swell may pose a greater risk for sneaker waves and
continued erosion of beach profiles. Stay tuned.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Frost Advisory from 9 PM this evening to 10 AM PST Friday
     for CAZ107-108-111.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Hazardous Seas Warning until 9 AM PST Friday for PZZ450-455-
     470-475.

&&

$$

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

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