370
FXUS66 KEKA 182126
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
126 PM PST Tue Nov 18 2025

.SYNOPSIS...Cooler and drier conditions expected through Wednesday.
A quick moving system arrives Wednesday evening, bringing breezy
south winds and rain across the area. Drier conditions expected by
Thursday afternoon through at least Sunday. Frost possible Friday
night into the weekend.


&&

.DISCUSSION...A brief period of dry weather is forecast through
most of Wednesday as a much drier airmass fills in behind this
system tonight, bringing chillier temperatures to the interior
areas. Lingering cloud cover is likely to keep high temperatures
this afternoon moderated, with even the warmest valleys struggling
to reach 60. Ample moisture from recent rains are likely to promote
cloud cover and patchy valley fog again tonight. Temperatures could
still drop into the mid to high 30s for the coldest valleys of
Trinity and northern Mendocino counties. These overnight
temperatures will likely be high enough to prevent widespread frost.

Another system is likely to arrive by late Wednesday evening,
returning gusty south winds and rain to the area. Most models show
this as a quick moving system bringing light to locally moderate
rain and breezy south winds. NBM is showing over 50% chances for
over 0.5" of rain north of Cape Mendocino. There is around a 40%
chances or higher for over 1" in Del Norte the King Range.
Generally, forecast amounts range from 0.25-0.5" across the area,
with localized areas over 1". South winds are not currently forecast
to be strong, though gusts of 25-35 mph are possible especially
along the coastal areas and in channeled terrain. Snow levels will
drop Wednesday night to 5000-5500 ft, but lower precipitation
potential in Trinity County will only support a dusting at Highway 3
around Scott Mountain Pass. Conditions quickly improve by Thursday
morning with only some lingering showers continuing by Thursday
afternoon.

Another break in the wet weather returns Friday and into the
weekend. Chilly overnight temperatures are likely, which could lead
to widespread frost as early as Friday morning if cloud cover clears
out. An additional system is possible early next week, but ensembles
are starting to trend this system northward. NBM is only showing a
50% chance for 0.1" in Del Norte Monday, with much lower
probabilities to the south. Even high-end precipitation amounts
(75th percentile) are only showing 0.25-0.50". JB


&&

.AVIATION...(18Z TAFS)...VFR conditions are forecast to prevail at
coastal aerodromes (KCEC and KACV) through the period. Shallow moist
air may result in brief MVFR vsbys this evening once mixing and
solar insolation ceases. IFR conditions are expected to redevelop in
the interior valleys overnight. Skies have been slow to clear out in
Trinity and portions of interior Humboldt this afternoon and may not
clear out at all. KUKI has cleared out, but IFR conditions will
likely (60% chance) redevelop aft 08Z. Toward the end of the
forecast period, MVFR cigs may (50% chance) spread back out over the
coastal plain around Humboldt Bay and over KACV after 14-16Z Wed as
winds turn south-southeasterly in advance of a front. Low level wind
shear and shallow severe turbulence will be possible (20% chance)
for over the coastal mountains and coastal airfields after 00z Thu
as a 35kt+ low level barrier jet develops.


&&

.MARINE...A frontal boundary will rapidly progress across the waters
Thu afternoon and evening bringing a brief period of gale force
winds by mid to late evening. High resolution 10 member ensemble
indicates 60-80% chance for gust > 34 kt, primarily in the outer
waters, and nearshore waters north of Trinidad head, around Pt St
George and north of Shelter Cove around Cape Mendo. There is a great
deal of small scale variability, timing and spatial differences
between all the HREF members. Thus a gale watch for gusts > 34 kt
has been hoisted after 4-7 PM Wed for the outer waters. Gusts > 34
kt are certainly expected inside 10NM, especially around headlands.
Large W-NW swell will begin to build Wed night and reach 15-17 feet
at 13-15 seconds by Thu morning. This swell will combine with short
period wind waves and seas will once again become quite hazardous. A
warning for seas may be necessary. Otherwise, northerly winds and
steep wind waves are generally forecast to prevail through the
remainder of the week. A series of large W-NW swell groups will also
propagate into the waters Thu through Sun.


&&

.BEACH HAZARDS...Long period W-NW swell from 8-12 ft with dominant
periods near 16 seconds is forecast to build over the weekend.
This swell may pose a moderate risk for sneaker waves as well as
continued erosion of beach profiles. Stay tuned.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PST Wednesday for PZZ450-
     455.

     Gale Warning until 11 PM PST this evening for PZZ470.

     Gale Watch from Wednesday afternoon through Wednesday
     evening for PZZ470.

     Gale Warning until 9 PM PST this evening for PZZ475.

     Gale Watch from Wednesday evening through late Wednesday
     night 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.

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