438
FXUS66 KEKA 280730
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1230 AM PDT Tue Jul 28 2026

.KEY MESSAGES...

* Moderate risk for sneaker waves along the Lost Coast and Mendocino
  Coast through Wednesday.

* Elevated fire danger Tuesday for interior areas due to breezy
  afternoon winds.

* Hot temperatures return late week into the weekend.

* Coastal stratus likely to form each night and clear each
  afternoon through at least the middle of the week.

&&

.SYNOPSIS...Near to slightly below normal temperatures are likely
for the interior areas, while near to slightly above normal coastal
temperatures are likely continue through Wednesday. Breezy
afternoon winds elevate fire danger in eastern Trinity, eastern
Mendocino, and Lake counties. Hot interior temperatures return
late this week.



&&

.DISCUSSION...The extended period of lighter northerly winds has
shut down much of the coastal upwelling. This created warmer than
average coastal water temperatures, into the low 60s, and a
weaker low level inversion. The lack of cool air advection from
the coastal waters and quickly dispersing daytime stratus will
once again lead to some warmer coastal temperatures Tuesday. The
northerlies will be trending higher this week, allowing for more
typical seabreeze temperature moderation.

A continued troughing pattern will once again bring breezy
afternoon wind gusts of 20 to 30 mph in the interior areas Tuesday
afternoon, mainly in the higher elevations and channeled terrain
(such as Clear Lake and the Trinity River valley). Low afternoon
relative humidities in Trinity, eastern Mendocino, and Lake
Counties along with these winds brings an elevated fire weather
threat.

There is high confidence in high pressure rebuilding over the area
later this week. NBM is showing moderate to high probabilities
for high temperatures in the triple digits for most interior
valleys starting Friday and continuing into next week. Currently,
minor to moderate HeatRisk is expected. /JB/JJW


&&

.AVIATION...06Z TAFs.Stratus reformed Monday evening after periods
of full clearing and VFR conditions. The marine layer has been
deepened by a passing weak shortwave, and a second one is forecast
to pass through Tuesday. This should maintain mostly MVFR to IFR
ceilings Tuesday. Coastal seas surface temperatures have been
warmer than average, in the low 60s, and this has contributed to a
largely weakened low level inversion. Aside for the potential for
some lingering stratus to get driven back to the coast with the
afternoon seabreeze, effective afternoon clearing is expected with
the weak inversion. VFR conditions will prevail for the interior.
Northerly winds will increase through the afternoon hours, with
some gusts near 20 kts expected at CEC, ACV and UKI. Stratus will
begin expanding back over the coast Tuesday evening, but should
not be initially too shallow. /JJW


&&

.MARINE...Northerly winds will begin trending higher over all
zones starting Tuesday. Winds north of Cape Mendocino look to
generally remain below 20 kts through the week. The focus of
stronger northerlies will remain around and south of Cape
Mendocino. Northerlies will strengthen to 20-25 kts in these
southern zones, locally with gale conditions up to 30 kts around
the cape. Short period northerly seas will increase over the
waters while a persistent small long period southerly swell is
reinforced by a second Tuesday. A ridge of high pressure will
strengthen through the weekend, bringing increased chances for
gale strength northerlies. /JJW


&&

.FIRE WEATHER...Breezy westerly winds will continue in the
afternoons Tuesday for interior areas and may be particularly
breezy with gusts of 20 to 30 mph over the ridges and channeled
terrain in eastern Trinity, northeast Mendocino, and Lake
Counties. These areas are forecast to have low afternoon RHs in
the teens and 20s. Localized and brief critical conditions are
possible with these low RHs and winds. Overnight recoveries are
expected to be good aside from the higher elevations of Lake and
eastern Trinity County.

Closer to the coast, a deep marine layer brings high RH and
perhaps stratus and/or fog into the river valleys overnight.
Afternoon RH ranges from 60s to 80s near the immediate coast to
20s to 40s in interior Humboldt, Del Norte, and western Mendocino
Counties.

Ridging rebuilds later this week into the weekend bringing much
warmer high temperatures to the interior with most valleys
forecast to reach the high 90s and triple digits. Afternoon
RHs will again be in the teens and 20s for the eastern interior.
Weak shortwaves arrive over this same period which may support
some breezier afternoons along with this heat and low afternoon
RH. Confidence is low at this time, but elevated fire weather
conditions are again possible. /JB



&&

.BEACH HAZARDS...A long period southerly swell with periods up to
19 seconds remains in from tropical systems in the Eastern
Pacific. A second reinforcing long period southerly swell will
arrive Tuesday. These energetic swells will bring a low to
moderate risk of sneaker waves that would be most hazardous on
steep, south and southwest facing beaches along the Lost Coast and
Mendocino Coast.

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! /JJW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement through Wednesday afternoon for
     CAZ104-109.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT Wednesday for PZZ455-
     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.

Visit us at https://www.weather.gov/eureka

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png