377
FXUS66 KEKA 061046
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
346 AM PDT Sun Sep 6 2026

.KEY MESSAGES...

- Slight chance of showers or a couple thunderstorms Tuesday over
  interior Del Norte and Trinity County Sunday.

- Overnight temperatures for the interior will remain chilly, yet
  fog formation could inhibit any frost forming within inland valleys.

- A building Desert Southwest ridge will sharply increase interior
  temperatures Monday, followed by further warming to above
  average temperatures into late next week.


&&

.SYNOPSIS...A slight chance for showers or isolated thunderstorms
this Sunday in Del Norte and extreme NE Humbodlt and Trinity
counties. This unsettled pattern could also disrupt diurnal
coastal stratus this weekend. Colder morning temperatures could
occur for the coldest interior valleys this morning wherever fog
does not form. A sharp warmup in temperatures will begin Monday
and continue into late next week.


&&

.DISCUSSION...Sunday, a shortwave disturbance passing over the
forecast area is increasing the rainfall chances for the Del Norte
and the northern portions of Trinity and Humboldt counties. A
very slight lightning chance exists for these areas well, yet NW
storm motion will likely cause any storms that do form to flow
into Siskiyou County quickly. Even the most extreme CAMs show very
limited coverage of short lived thunderstorms over the area.
Little chances for wetting rain (>0.10") exist for areas away from
the high terrain inland for Sunday as well.

A sharp warmup will begin Monday as a strong Desert Southwest ridge
develops. Temperatures in the interior valleys may near or reach 100
mid to late next week. Of note, 70s are possible to the coast,
with mid 80s to low 90s not too far inland. These values would
bring a Moderate HeatRisk to the region, including closer to the
coast. NBM has high chances for this occurrence. After the stretch
of cooler weather from persistent troughing, the fast warm up
will not allow for much acclimation time. Likely aided by offshore
winds, Wednesday looks like the warmest day of the stretch.

There are remaining questions about whether tropical moisture may
stream northeast toward the region from decaying tropical systems
well off the CA coast. Model guidance has a large variance in
possibilities ranging from completely dry after Sunday to several
chances of showers and possibly thunderstorms late week or through
the weekend. NBM chances for a wetting rain of at least 0.1 inch
are only 25% at this time Friday and through next weekend
however.


&&

.AVIATION...Calm winds continue through Sunday morning. A passing
shortwave trough is deepening the marine layer, but a shallow
layer has persisted to bring LIFR ceilings. Instability
associated with the trough looks to help disrupt the low level
inversion Sunday. The only hindrance to faster clearing for the
coastal terminals will be weak southerly winds around an expected
coastal eddy. Some northwest winds deliver some gusts over the
afternoon hours while interior terminals stay VFR.


&&

.MARINE...Northerly winds have strengthened, mainly over the
southern waters. A mid period NW swell is subsiding. Hurricane
Marie has delivered a long period southerly swell up to 5 ft at 17
seconds which will remain in the waters into next week. The
northerlies begin to strengthen Sunday afternoon through Monday
with winds 20 to 25 kts. Winds will begin to ease late Tuesday as
a strong area of high pressure build in from the SE. Wednesday
looks to give a break in winds with some offshore flow over the
coast. There is some uncertainty in how fast the northerlies
restrengthen Thursday or Friday.

&&

.BEACH HAZARDS...Hurricane Marie is ushering in a long period
southerly swell of 3-5 feet at 17 seconds for south facing beaches
in Mendocino and Southern Humboldt counties, including the Lost
Coast Trail today through into Sunday. Thus, there is an ongoing
risk of sneaker waves, especially if the swell comes in slightly
larger.

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 there recently.
Stay safe and never turn your back on the ocean!


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement through Monday evening for CAZ104-
     109.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 2 PM Sunday to 5 AM PDT Monday
     for PZZ455.

     Small Craft Advisory from 2 PM Sunday to 5 PM PDT Monday
     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