456
FXUS66 KEKA 150701
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1201 AM PDT Tue Jul 15 2025

.SYNOPSIS...Temperatures start trending down today, but high
temperatures remain warm. There is a slight chance for thunderstorms
in northern Trinity County this afternoon and evening.


&&

.DISCUSSION...An upper level trough is moving into the Pacific
Northwest, weakening the ridge. High temperatures today are forecast
to be around 5-10 degrees cooler in the interior, with 90`s likely
for most areas. Some of the warmest areas may still see triple
digits, including northeast Humboldt and Trinity County. A deeper
marine layer might bring drizzle to the coastal areas, with slightly
higher confidence along the Mendocino coast.

There is a slight chance (10-15%) for dry thunderstorms in northern
Trinity County this afternoon. Model soundings show some elevated
instability, and some moisture remains available. Confidence is low
as there is still some CIN, but chances are not zero. The setup
remains similar Wednesday afternoon, but with slightly less moisture
available. CAMs are showing a better setup in Siskiyou County, but
these could drift westward into Del Norte. Chances remain low, 5-
10%, but will need to be watched.

A similar pattern remains in place for much of the week with a
series of shortwaves moving into the Pacific Northeast. This will
keep temperatures moderated in the 90`s. By Thursday, NBM
probabilities of triple digits in Trinity and northeast Humboldt
fall off to less than 30% into the weekend. JB


&&

.AVIATION...A deeper stratus layer will continue to develop and
cover the North Coast into early Tuesday morning. A weak frontal
boundary will traverse the region early Tuesday morning aiding in
the deepening of the marine layer, while also bringing the potential
for light drizzle to terminals around Humboldt Bay with IFR to LIFR
conditions likely. Stronger reversal southerly winds around the Del
Norte Coast will delay the beginning of stratus encroachment, but
IFR to potentially LIFR conditions could occur a few hours before
sunrise on Tuesday. VFR conditions are expected for interior areas
with potential for smokey conditions in Trinity, interior Humboldt
and NE Mendocino counties.


&&

.MARINE...Gale force winds are expected across the outer waters into
Tuesday morning, with gusts exceeding 40 to 45 knots possible. As
these winds push towards the coast, near- gale to gale gusts are
possible nearshore of Point Saint George and Cape Mendocino. Steep
wind driven seas 12 to 17 feet are expected through Tuesday
afternoon, with the strongest winds and waves expected into Tuesday
morning in the outer waters. High pressure will begin to break down
Tuesday afternoon, diminishing hazardous conditions by midweek.


&&

.FIRE WEATHER...Breezy offshore winds overnight start to gradually
weaken tonight, but westerly gusts of 15-20 mph are possible in the
afternoons in the higher terrain. Afternoon RHs remain dry, but
overnight recoveries are generally good outside the highest terrain.
Temperatures trend downward this week, though 90`s are still likely
in most valleys.

Upper-level moisture along with elevated instability brings a 10-15%
chance for isolated dry thunderstorms in northern Trinity County
this afternoon and evening. Moisture and instability decreases by
Wednesday into later in the week, along with thunderstorm chances. JB


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Hazardous Seas Warning until 11 AM PDT this morning for
     PZZ450.

     Small Craft Advisory until 11 AM PDT this morning for
     PZZ455.

     Gale Warning until 11 AM PDT this morning for PZZ470.

     Gale Warning until 9 AM PDT this morning 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