028
FXUS66 KEKA 030701
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1201 AM PDT Sun Aug 3 2025

.SYNOPSIS...Interior thunderstorms around the Trinity Horn will
threaten to continue for Sunday. Ridging into this coming week will
warm temperatures with potential for another trough next week.

&&

.DISCUSSION...A recurring theme of late afternoon convective
weather will continue Sunday afternoon. The usual areas around the
Klamath Mountains in Northern Trinity County are forecasted for
about a 15-25% probability to have rainshowers or thunderstorms in
the extreme NE regions of Trinity County near Trinity Center as the
most likely location for any shower/thunderstorm development. The
potential for thunderstorms decrease substantially on Monday with
drier westerly flow spreading across the area and higher 500mb
heights. This is due to a colder trough approaching on Sunday
bringing the final forecasted round of showers and thunderstorms to
the interior mountains. Otherwise, this trough will bring cooler
temps and gusty westerly and northwesterly winds Sun and into Mon
for most of the interior areas and coastal river valleys.


Interior temperatures will likely begin to warm by Tuesday or
Wednesday of next week. The duration of warmer temperatures remains
uncertain. 500mb heights pump up to 588dm or more by late next week.
With these this hot air mass moving overhead, some of the typically
hot valley locations will reach, or exceed, 100F late in the coming
week. Even coastal areas have a potential for high temperatures
reaching the mid to upper 60s by later in the week, with a 20%
probability of reaching a max temperature over 70F around Humboldt
Bay next weekend.

&&

.AVIATION...The upper level trough that is moving through the area
has weakened the inversion. This allowed skies to clear out at the
coast Saturday evening. IFR ceilings are spreading around the
coastal areas again this morning. Some drizzle is possible as the
trough moves overhead. This weaker inversion and slightly stronger
northwest winds in the afternoon is expected to clear out much of
the coast on Sunday. Coastal stratus is expected to return Sunday
evening, although it may be later in the evening again. Inland areas
are expected to remain mainly clear, although there is a slight
chance of thunderstorms in far northern Trinity county once again.
Breezy northwest winds are expected as well.

&&

.MARINE...An upper level trough moving over the area is
expected to slightly increase northerly winds in the waters this
morning. The waves are mainly short period and driven by the local
winds. These are stronger south of Cape Mendocino where they peak
around 7 feet. Monday the winds are expected to start to diminish,
but are expected to remain in the 10 to 20 kt range through early
Thursday. Friday it looks like stronger northerly winds will return.

The waves are expected to continue to be mainly in response to the
local winds. The 1 to 2 foot southerly swell is currently moving
through the waters and there will likely continue to be some small
southerly swells at times over the next week. The first
northwesterly swell in a while is expected to move into the waters
early Wednesday. This is expected to build to around 5 feet at 12
seconds and continue into Thursday.

The Tsunami continues to produce small waves. These continue
to be mainly less than 6 inches in Crescent City now. They are
expected to continue to diminish, but this has been slow. Despite
their small size these may continue to bring some increased currents
and surges for a bit longer. MKK

&&

.FIRE WEATHER...We will continue to include a headline in the
fire weather forecast for isolated thunderstorms and possible new
ignitions through Sunday in Zone 283. One more round of showers and
thunderstorms for the Klamath Mountains (15-25% probability), mostly
around the Trinity Horn Sunday afternoon, is forecast before an
incoming upper level trough/cold front will change our current
weather pattern.

This trough will likely induce stronger westerly to northwest winds
for our typically dry and windy areas; Lake, southern Mendocino and
eastern Trinity. Low daytime RHs in the mid 20% or so and fairly
strong wind gusts for the season due to the trough/cold front
passing overhead and also warrant a headline fore Fire Weather Zones
283, 277, & 264. Southern Lake County and Interior Mendocino show a
60-90% probability for wind gusts over 30mph Sunday afternoon.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT Monday for PZZ455-475.

     Small Craft Advisory until 3 PM PDT Sunday for PZZ470.

&&

$$

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