747
FXUS66 KEKA 180842
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1242 AM PST Tue Nov 18 2025

.SYNOPSIS...Breezy winds will continue to ease into early Tuesday
for Lake County. Frost will be possible Wednesday morning for the
interior. Additional rain is possible late Wednesday into
Thursday.


&&

.DISCUSSION...Winds have generally diminished for the area,
except in Lake County, where elevated easterly winds will gradually
diminish into early Tuesday. Wind gusts of 20-30 mph are possible,
with locally higher gusts possible over higher terrain.

A brief period of dry weather is forecast Tuesday and most of
Wednesday as a much drier airmass fills in behind this system
tonight, bringing chillier temperatures to the interior areas. The
widespread rain has generally brought valley fog early Tuesday
morning, which is aiding in keeping temperatures just high enough to
prevent frost. Generally mid to high 30s are forecast for the
valleys of Trinity and northern Mendocino. A dry, but cooler day is
forecast for much of the area Tuesday into Wednesday. Overnight low
temperatures are forecast to be chilly again Tuesday night and
Wednesday morning. There is still uncertainty on if frost will
develop as ample moisture will likely still be available and could
lead to areas of patchy valley fog and keep temperatures high enough
to prevent frost. Additionally, an approaching system could bring in
high clouds, further lowering confidence. NBM does show high (>50%)
probabilities for temperatures less than 36F in Trinity, areas of
Lake, northern Mendocino; but for the above reasons, confidence is
low.

Another system is likely to arrive by late Wednesday evening,
returning gusty south winds and rain to the area. So far, most
ensembles show this as a quick moving system with a punch of
moderate to locally heavy rain and breezy south winds. NBM is
showing around a 20-40% chance for over 1 inch of rain north of Cape
Mendocino, with higher probabilities in the higher terrain of the
King Range and Del Norte. Generally, forecast amounts range from
0.50-1.25 inches across the area, with localized areas over 2
inches. South winds are not currently forecast to be strong, though
gusts of 20-30 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 around an inch at Highway 3 around Scott Mountain
Pass.

Another break in the wet weather returns Friday and into the
weekend. Chilly overnight temperatures are likely, which could lead
to frost as early as Friday morning if cloud cover clears out. An
additional system is possible early next week. JB



&&

.AVIATION...06Z TAFs...Lingering wrap around moisture has departed
the area Tuesday morning. As skies cleared and cooled, abundant
stratus and areas of fog developed in the wake of the recent rains.
Confidence is high for persistent fog over the interior valleys,
including around UKI. Northerly winds over the immediate coast, and
developing light offshore winds makes the duration of coastal fog
less certain for the coastal terminals. Periods of calm winds
allowed for rather quick radiational fog development for the coast,
including ACV. Winds are forecast to remain slightly higher at CEC,
but stratus and VCFG are expected. Late morning clearing will firmly
return conditions to VFR. Northerly winds will restrengthen Tuesday
afternoon for the coast, but gusts will mostly be under 20 kts for
ACV and CEC. JJW


&&

.MARINE...A small surface low to the south around Point Arena
continues to increase the pressure gradient against strong ridging
to the west. The subsequent prolonged gale conditions and steep,
hazardous seas will be very slow to subside as the surface low
weakens and pulls south Tuesday. The ongoing Gale Warnings in the
outer waters have been extended for this reason. Steep seas will
continue to propagate into the inner zones, and seas may be
periodically hazardous. A northwest swell will subside through
Wednesday. Winds will quickly strengthen from the south Wednesday
ahead of a North Pacific trough. A period of Gale conditions may
develop Wednesday afternoon through Wednesday night. A large post
frontal westerly swell will follow the trough Thursday. JJW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Hazardous Seas Warning until 3 AM PST early this morning
     for PZZ450-455.

     Gale Warning until 9 PM PST this evening 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