Area Forecast Discussion
Issued by NWS Eureka, CA
Issued by NWS Eureka, CA
710
FXUS66 KEKA 101948
AFDEKA
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1248 PM PDT Thu Sep 10 2026
.KEY MESSAGES...
* Warmer interior temperatures continue today, before a cooling
trend arrives Friday into the weekend.
* Chances for light rainfall for Del Norte and northern Humboldt
Saturday.
* Elevated fire danger each afternoon through Saturday for the
interior.
&&
.SYNOPSIS...Cooler temperatures return to the coast today and
across the area Friday into the weekend. Light rain is possible
for the northern half of the area Saturday. Westerly to
northwesterly winds will increase the fire risk for the interior
through Saturday.
&&
.DISCUSSION...High pressure begins to weaken today as a trough
moves into the Pacific Northwest. Weakened offshore flow has
allowed for coastal stratus to form with fog being reported along
much of the Humboldt and Del Norte coasts. Some clearing is
possible this afternoon, but still this will bring a much cooler
day to the coast than yesterday. Along with coastal stratus, high
clouds and virga showers from the remnants of Hurricane Marie are
streaming into the area. This produced a few showers and a few
lightning strikes this morning. This potential has waned as the
bulk of the moisture has moved eastward, but the high clouds have
been helping cool the interior temperatures slightly.
Interior temperatures remain relatively warm today in the 90s to
just over 100, but temperatures will cool significantly with the
trough moves in, with high temperatures over 10 degrees cooler by
Friday. By this weekend, much of the interior is forecast to be
in the 70s and 80s with the coast in the low 60s. A weak front
moving through the northern portions of the area will bring a
chance for light rain to Del Norte and northern Humboldt counties.
Chances have waned a bit as models trend this slightly northward,
but still the chance for measurable rain is around 75% for much of
Del Norte and around 20% in northern Humboldt north of Eureka. The
chance for wetting rain (0.1" or more) in Del Norte is around 50%
and around 10% in northern Humboldt County.
Post frontal westerly winds will be breezy Saturday afternoon to
the eastern portions of the area. The probability of wind gusts
over 30 mph are above 50% for much of Lake County, eastern
Mendocino, and the Trinity River Valley in eastern Trinity
County. This will elevate fire weather concerns as these winds
will be especially strong; and relative humidities, while higher,
will still be low in the afternoon. See the fire weather section
below for more information.
High pressure is likely to return again early next week, returning near-
normal temperatures and dry weather to the area. /JB
&&
.AVIATION...(18Z TAFs)...Stratus and fog has remained persistent
along the Humboldt and Del Norte coasts bringing LIFR conditions
into the afternoon. An eddy off the coast has continued to
reinforce stratus that does erode. Temporary scattering and
visibility improvements are possible this afternoon, but LIFR to
IFR conditions are likely to continue into the evening and
overnight. Fog is likely again at the coastal terminals overnight
with a shallow marine layer. Interior areas remain VFR with gusty
northwesterly winds this afternoon. /JB
&&
.MARINE...Breezy northerly winds return Thursday, particularly
in the lee of Cape Mendocino. Near gale force gusts are possible
by Thursday evening in the lee of Cape Mendocino and Cape Blanco.
Steep seas may propagate into the nearshore waters even as winds
remain relatively light, especially south of Cape Mendocino. Winds
ease Friday north of Cape Mendocino and Saturday south of the Cape
as a weak front moves through the area. Strong northerlies return
Sunday. Along with wind driven seas, a long period south swell
from Hurricane Marie at around 2 to 3 ft continues through the
waters. /JB
&&
.FIRE WEATHER...Much warmer and drier conditions continue today,
although offshore flow has weakened and marine influence started
to return. Slightly higher afternoon RH is expected today along
with breezy afternoon winds. Because afternoon RH is still low
(teens and 20s), breezy winds of 10 to 15 mph will bring elevated
to locally critical fire weather conditions. The greatest threat
will be in Lake County and eastern Trinity County in the lower
elevations where terrain channeling will locally enhance winds.
Troughing Friday into the weekend will return cooler temperatures
and a deeper marine layer. Afternoon westerly to northwesterly
winds will increase further Friday and especially Saturday. A weak
front Saturday morning and early afternoon might support wetting
rain for Del Norte County, but elsewhere, the only impact will be
cooler weather, more cloud cover, and especially gusty onshore
winds. Wind gusts of 30 to 40 mph are possible in Lake, southern
Mendocino, and eastern Trinity Counties Saturday afternoon. RH
will rise with this onshore push of winds from the 20s to the 40s,
so the fire threat will be subdued somewhat. Still, elevated to
locally critical fire conditions are expected, especially for the
eastern portions of the area where RHs will rise slower. /JB
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory from 4 AM Friday to 3 AM PDT Saturday
for PZZ455.
Small Craft Advisory until 3 PM PDT Friday for PZZ470.
Small Craft Advisory until 3 AM PDT Saturday 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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see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png