833
FXUS66 KEKA 292147
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
247 PM PDT Tue Sep 29 2026

.KEY MESSAGES...

* High pressure builds through the rest of the week, bringing an
  extended dry period with interior valley high temperatures warming
  into the 80s and 90s.

* A long-period west-northwest swell brings an elevated risk for
  sneaker waves along the shoreline.

* Widespread gusty winds with gusts from 20 to 25 mph expected
  today; wind prone areas of coastal Del Norte and the King Range
  could see gusts up to 35 mph today and tomorrow.



&&

.SYNOPSIS...Upper-level ridging builds over the West Coast this
week, supporting a progressive inland warming trend and dry
conditions through this coming weekend.


&&

.DISCUSSION...Broad mid-level ridging over the eastern Pacific will
expand inland today through Friday, establishing high confidence
in dry conditions across the region.

At the surface, the onshore pressure gradient between the offshore
eastern Pacific high and the interior thermal low will drive fresh
northerly winds along shore, strongest south of Cape Mendocino.
Additionally, conditions will be gusty for many locations across
Northwest California. Gusts greater than 20 mph could be possible
this afternoon/evening with an 80% chance or higher for coastal
areas from Del Norte to Mendocino, and more widespread chances for
all of southern Humboldt and most of Mendocino and Lake counties,
and for the ridges of Del Norte and Trinity counties. There is,
also, an 80 percent chance or higher for gusts over 25 mph for
all coastal areas along with the King Range and higher elevations
of interior southern Mendocino and Lake counties. This afternoon
and tomorrow afternoon, just along the Del Norte Coast north of
Pt St George and the King Range have over a 70 percent chance for
gusts over 35 mph.

Strong atmospheric sinking beneath the upper ridge will steadily
warm the air mass aloft. Thermal profiles across interior valleys
will support afternoon maximum temperatures climbing into the 80s
and 90s mid-week. Ensemble guidance highlights a 75% to 90% probability
of interior valley highs exceeding 90F Wednesday through the end
of the week (this mostly includes the Trinity River Valley,
the warmest valleys of southern Humboldt and southern Trinity
counties, interior valleys of Mendocino and Lake counties).


&&

.AVIATION...Gusty northerly to northwesterly winds will surge
this afternoon for many terminals in Northwest California. Gusts
from 20 to 30 knots could occur for many coastal terminals this
afternoon. There could also be periods of low ceilings or
visibility this afternoon/evening due to low to mid level clouds
pushing up onshore with the winds. As winds diminish this
evening, there is a chance for IFR/LIFR ceilings for coastal
terminals and down coastal river valleys. It is more likely that
low ceilings will form and linger around the Eel River Delta and
Humboldt Bay late this evening and overnight. VFR conditions are
anticipated for many interior terminals.


&&

.MARINE...Fresh northerlies continue due to the pressure gradient
between offshore high pressure and the interior thermal trough.

* Northern Inner Waters: Northerlies of 10 to 20 kt will generate
  steep short-period seas. A west-northwest swell at 12 to 14
  seconds continues today. A Small Craft Advisory remains in
  effect through Thursday morning.

* Northern Outer Waters: Northerlies of 20 to 25 kt with gusts to
  35 kt (mainly in the lee of Cape Blanco) will build combined
  seas to 10 to 11 ft. A Small Craft Advisory remains active
  through early Wednesday morning with a Gale Warning taking over
  until Thursday morning.

* Southern Inner Waters: Fresh to strong northwest winds of 20 to
  25 kt with gusts to 35 kt (mainly in the lee of Cape Mendocino)
  will maintain steep seas. A Gale Warning has taken effect and
  will remain in effect through late this evening.

* Southern Outer Waters: Gale force conditions develop in the lee
  of Cape Mendocino, where northerly winds of 25 to 30 kt with
  gusts up to 40 kt will yield steep, hazardous combined seas of
  11 to 12 ft. A Gale Warning remains in effect through Thursday
  morning.


&&

.BEACH HAZARDS...A long period west northwest swell at 3 to 6 ft with
a period up to 17 seconds continues to diminish today, also
lowering the threat of sneaker waves. The smaller period south
swell will continue to persist through today despite not being as
impactful. It is still in all beachgoers and water
recreationists to use caution, especially on south facing
beaches. High astronomical tides will increase the danger,
especially over rocks and jetties.

Sneaker waves are a unique hazard, with up to 30 minutes between
waves. Large, unexpected waves can sweep across the beach without
warning, sweeping people into the sea from rocks, jetties, and
beaches. These sneaker waves can also move large objects such as
logs, crushing anyone caught underneath. Even ankle to knee deep
water can knock you down and drag you out when a sneaker wave hits.
Pay attention and stay above the high water line and any wet sand to
stay safe. If the ground is wet, waves have surged.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT Thursday for PZZ450.

     Small Craft Advisory until noon PDT today for PZZ455.

     Gale Warning until 9 PM PDT this evening for PZZ455.

     Small Craft Advisory until 6 AM PDT Wednesday for PZZ470.

     Gale Warning from 6 AM Wednesday to 9 AM PDT Thursday for
     PZZ470.

     Gale Warning until 9 AM PDT Thursday 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