Area Forecast Discussion
Issued by NWS Eureka, CA

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608
FXUS66 KEKA 022242
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
342 PM PDT Sat May 2 2026

.SYNOPSIS...The risk of thunderstorms over the the interior will
peak Sunday afternoon and evening. Cooler conditions will briefly
build Monday with warmer and mostly calm conditions for most of the
week.

&&

.KEY MESSAGES...

-Scattered and some isolated strong thunderstorms (15-25% chance)
over the the interior Sunday afternoon with some storms pushing
closer to shore.

-Cooler and cloudy conditions Monday followed by warmer and generally
calm conditions by midweek.


&&

.DISCUSSION...A weak shortwave continues to influence the area
today. Marine influence has lifted higher but remains robust along
the coast, particularly north of Cape Mendocino and into the Eel
River Valley. Despite persistent instability across the interior,
moisture has so far remained too low and surface forcing to weak to
create much more than cumulus clouds. some isolated thunderstorms
remain possible (10% chance) this evening with some potential for
storms into Del Norte County.

The shortwave will continue to morph into a cutoff low which will
pass and begin to travel south of the area on Sunday, generally
sticking to the shore. As the low pushes south, it will help pull
more tropical moisture around and up the Sacramento Valley.
Precipitable water increasing above 1.0 inch combined with
persistent moderate instability and some marginal shear will
increase the risk of scattered thunderstorms (20% chance over the
northern interior) with a some potential for isolated severe storms
in Trinity county. Storm potential will peak late Sunday afternoon
and into the early evening. Easterly steering flow will help push
any storms that do form closer to shore, though any storms will
weaken as they move to the west off the high terrain. Stronger
storms could create 0.3 to 0.6 inches of heavy rain, strong outflow
winds, and some damaging hail. The strongest storms will be in
Trinity and far eastern Humboldt and Del Norte Counties. Due to the
track of the low, storm chances are much lower in Mendocino and Lake
Counties. Meanwhile, an elevated, gloomy marine layer will most
likely persist along the coast.

Drier conditions will quickly return by Monday and Tuesday. Colder
air being pulled from the northeast aided by lingering clouds will
briefly cool interior temperatures into the 60s Tuesday. Clouds and
valley moisture will limit any frost concerns. The east wind will
likely help erode and shallow the marine layer, but most models show
stratus persisting through the early week. Benign and weak high
pressure will build late in the week, bringing slightly warmer than
average temperatures but otherwise dry, seasonable, and calm
weather. /JHW


&&

.AVIATION...Coastal stratus continues along the North Coast again
today. Strong northerly surface winds have moved off shore allowing
variable to southerly winds to develop. THis southerly surge
increases the likelihood of stratus returning to KCEC if any clearing
happens this afternoon. KACV is expected to be socked in with MVFR
categories through the day with overnight conditions dropping down
into IFR as ceilings lower slightly and increased mist forms.
Inland, daytime heating is mixing away the valley stratus giving way
to VFR conditions. There is a slight (10-20%) thunderstorm threat
for interior NW CA, yet observed high cloud coverage could keep a
cap on any formation of these cells. Valley fog is likely to return
tonight to interior valleys with conditions dropping down to LIFR in
the early morning.


&&

.MARINE...Low pressure over the interior interacting with a
skinny ridge of high pressure in the NE Pacific is reinforcing the
strong surface pressure gradient over the coastal waters. This
synoptic scale setup is resulting in continued northerly winds over
the waters as well as large, steep seas. While the largest waves (up
to sig. heights of 13-15ft) are modeled for the outer waters, steep
seas of 7 to 9 ft are propagating into the inners. Near-gale
conditions with localized areas of gale force gusts will continue
through the day before decreasing after sunset. A Small Craft
advisory has been issued for the outer waters due to the continued
steep, short period seas.

This evening, a cold air mass will approach the western seaboard,
this cold air will disrupt the surface pressure gradient allowing
the northerly winds to weaken down to gentle breezy conditions. This
will begin an extended period of lighter winds and smaller seas
through next week as relatively light winds flow over the coastal
waters. From Sunday through the week, the GFS wave model shows two
main swells impacting the coastal waters, the first is a long
period, westerly swell building up to 6ft@15s and another is a NW
swell of 4ft@8s. Minimal impact is expected next week from fresh,
short period waves.


&&

.BEACH HAZARDS...Sunday morning, a long period northwest swell with
periods between 17-20 seconds will arrive. This swell continues to
be monitored as it may pose a moderate risk of sneaker waves for
coastal areas. A Beach Hazards Statement has been issued for the
coast Sunday. Sneaker waves are anomalously large, unexpected waves
that sweep across beaches without warning. There can be up to 30
minutes of smaller waves before a sneaker wave arrives to the
shoreline. Choose your recreation wisely by avoiding steep beaches
and jetties as well as staying much farther back from the ocean than
normal. Never turn your back on the ocean!


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement from 11 PM PDT this evening through
     Sunday evening for CAZ101-103-104-109.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT this evening for PZZ470.

     Small Craft Advisory until 4 PM PDT this afternoon 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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https://www.weather.gov/images/eka/zonemap.png