783
FXUS66 KEKA 131924
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1224 PM PDT Sun Jul 13 2025

.SYNOPSIS...Excessive heat is forecast to continue in the interior
through Monday. Temperatures and heat risk are forecast to diminish
by mid week, but it will still feel hot all week. Isolated dry
lightning remains a very remote possibility for the northern
Trinity mountains through early next week.

&&

.DISCUSSION...

Hot weather continues in the interior, with high temperatures
between 100 and 110 likely. The highest temperatures are likely
along the Trinity and Klamath Rivers in Trinity and Humboldt
Counties. Slightly lower temperatures are found in Mendocino as
marine influence increases humidities and lowers temperatures.
This heat does bring Moderate to Major HeatRisk and is dangerous
to those without proper cooling and those sensitive to heat
related illness.

Smoke and haze models are showing higher smoke concentrations in the
valleys this morning before improving in the afternoon. Greater
instability today may help more haze to mix out and better air
qualities except immediately downwind from the fires. Models are
showing a moisture intrusion coming from the east. Moisture combined
with elevated instability may also bring a slight chance (10-15%)
for an isolated thunderstorm to northern Trinity County. Model
soundings do show a weak capping inversion and moisture remains
limited, so confidence remains low. There is a similar setup Monday
and Tuesday, but confidence is even lower (5-10% chance for an
isolated thunderstorm).

The ridge begins to move eastward Tuesday and Wednesday, allowing
for the marine layer to deepen and some relief to the hottest
temperatures. Temperatures are likely to remain warm, especially in
Trinity County, with mid to high 90s, but the consistent triple
digits are likely to end.

&&

.AVIATION...

Coastal stratus has retreated to the immediate shoreline as
inland daytime temperatures increase. Breezy conditions expected
again along the coast with westerly gusts 10 to 15 knots possible
this afternoon. UKI will remain clear with breezy WNW winds 10 to
15 knots. Increasing northerly winds offshore will help to scour
out some of the stratus layer, but a persistent southerly reversal
will likely keep cloud cover nearshore and the coastal terminals
IFR to LIFR. Brief scattering is possible prior to 00Z, but IFR
ceilings are expected to return late this evening (HREF >50%).
Strong northerly winds will push closer to the coast overnight
into early Monday morning. HREF probabilities for IFR ceilings
quickly fall below 50% after 12Z for CEC while ACV may hang onto
cloud cover through 18Z. Gusty winds expected through Monday
afternoon with >30 knots possible at CEC.

&&

.MARINE...

Gale force winds in the northern outer waters will gradually
expand southward in coverage this afternoon into Monday, with gusts
exceeding 40 to 45 knots likely in NW PZZ470. As these winds push
towards the coast, near- gale to gale gusts are possible nearshore
of Point Saint George and Cape Mendocino, especially Monday
afternoon. Steep and hazardous seas 9 to 14 feet will likely
propagate into the inner waters as well. Steep wind driven seas 12
to 16 feet are expected through Tuesday, especially in the outer
waters. High pressure will begin to break down Tuesday afternoon,
diminishing hazardous conditions by midweek.

&&

.FIRE WEATHER...

Building high pressure along with offshore flow has brought warming
and drying to the interior and near-coastal areas. Afternoon RHs
remain very dry, into the teens and 20s across most the interior.
High elevation areas (above 2000-2500 ft or so) continue to see
moderate to poor overnight RH recoveries. Lower elevations are
largely seeing moderate to good overnight recoveries. Offshore
winds in the higher terrain are forecast to remain breezy overnight,
especially in Del Norte county, though at least Monday morning.
Offshore flow begins to weaken slightly Monday night and Tuesday
morning, and more significantly by Tuesday night.

Upper-level moisture arrives from the east this afternoon into early
next week. Elevated instability along with some moisture brings a
slight chance (10-15%) for isolated dry thunderstorms to northern
Trinity County. As of now, moisture looks more limited on Monday,
but there is still a 5-10% chance for isolated dry thunderstorms.

The ridge begins to weaken Monday into early next week, which will
slowly deepen the marine layer into the middle of next week. RHs
will improve in the near-coastal areas with moderate to good
overnight recoveries possible in the highest terrain by the Tuesday
or Wednesday.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Extreme Heat Warning until 11 PM PDT Monday for CAZ102-105-
     107-108.

     Heat Advisory until 11 PM PDT Monday for CAZ106.

     Heat Advisory until 11 PM PDT this evening for CAZ110-111-
     113>115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 11 AM PDT Monday for PZZ450-475.

     Hazardous Seas Warning from 11 AM Monday to 11 AM PDT
     Tuesday for PZZ450-475.

     Small Craft Advisory from 5 PM Monday to 11 AM PDT Tuesday
     for PZZ455.

     Hazardous Seas Warning until 5 PM PDT this afternoon for
     PZZ470.

     Gale Warning from 5 PM this afternoon to 11 AM PDT Tuesday
     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