883
FXUS66 KEKA 082032
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
132 PM PDT Fri Aug 8 2025

.SYNOPSIS...Hot and dry conditions will continue to build through
the weekend with heat peaking across the interior on Sunday.
Gusty offshore winds are expected over the higher terrain in Del
Norte County this evening into Saturday morning. Breezy northerly
winds over the coastal headlands are forecast along the North
Coast this afternoon.


&&

.DISCUSSION...A strong H5 ridge and surface high pressure
continues to build into the Pacific Northwest and Northern
California today and through the weekend. Breezy to locally windy
east-northeast winds will persist through the weekend. Expect
offshore gusts from 25 to 40 mph tonight and into Saturday over
the higher terrain areas of Del Norte and the windier ridges of
the far northern interior of Humboldt County. This offshore flow
will bring an increasingly dry airmass to the area, yielding
mostly clear skies. See the Fire Weather section for more details.
In addition, breezy conditions with gusty north winds are
expected to continue this afternoon over the coastal headlands
and exposed ridges along the North Coast.

Upper level heights will rise across the region this weekend
through Monday, with a warm deep-layer air-mass developing across
the WRN CONUS. Model guidance has been very consistent supporting
850 mb temperatures of 25 to 30C, or so, over much of the
interior. Gentle offshore flow will aid in promoting peak
temperatures along the coast and portions of interior Humboldt and
Del Norte counties on Saturday. While the interior heat will
mostly have a peak in temperatures either Sunday or Monday.

Due to the gentle offshore flow on Saturday, coastal areas are
forecast to warm up, as well, with highs in the 70`s. Additionally,
adjacent coastal areas could reach the low 80`s. Highs for
interior Del Norte and Humboldt counties are forecast to be over
100 degrees, with the hottest temperatures around 108F in Willow
Creek. On Sunday, high temperatures in the hottest valleys are
expected to range from 100 to around 110F degrees, especially in
Trinity County. The HeatRisk is forecast to be moderate over the
area, but a major HeatRisk is expected to occur over portions of
interior Del Norte and Humboldt counties on Saturday, and for
Trinity County Saturday through Monday. Major HeatRisks are
expected for the interior valleys.

With the increasing heat ramping up on Saturday, a Heat Advisory
continues for interior Del Norte and northern interior Humboldt.
Additionally, a Heat Advisory has been added for Sunday for
interior Del Norte and northern interior Humboldt. Also, a Heat
advisory has been added for the HWY 101 corridor through
Mendocino County due to areas of both major and moderate HeatRisk.
A Heat Advisory has been added for Northern Trinity on Saturday,
as well, accompanying the Heat Advisory for Sunday. The heat will
have impacts to all individuals without cooling/hydration as well
as health systems and industries.

Tuesday, a shortwave trough will gradually squeeze down the coast
bringing a return to cooler weather and enhanced onshore flow.
/ZVS


&&

.AVIATION...VFR is expected today across the forecast area. Gusty
coastal winds building through the afternoon to gusts of 30kts at
coastal terminals. Low, but not zero percent, chance of degraded
visibilities from wind carrying sea spray over terminal spaces.
Winds calming tonight to light offshore flow leading to high
confidence on VFR conditions overnight as well (evaporation fog
possible within the first few meters above the surface 12Z-16Z).
height density issues possible inland as temperatures rise above
triple digits.


&&

.MARINE...High pressure building to the west has brought strong
northerly winds to the coastal waters. Winds are strongest in the
outer waters and in the lee of Cape Mendocino and Pt. St. George,
where gale force gusts of 35-40 kts are likely. Elevated, steep wind
wave dominated seas are expected with these winds, and will continue
to remain large through the weekend with heights up to 15ft@10secs
possible. Localized areas of gusts over 40 kts are possible (80-
100%) in the northern outer waters downwind of Cape Blanco.

Nearshore, wind gusts are generally lighter at around 10-20 kts with
areas near Pt. St. George and Cape Mendocino showing stronger
winds. near shore seas will also be steep and elevated as wind waves
propagate in from the northwest. Saturday, winds ease south of Cape
Mendocino and shift to being strongest farthest from the coast.
Gales are still likely in the northern outer waters and around Pt.
St. George, however elsewhere peak gusts of 10-15 kts are forecast.
The Mendocino/Southern HUmboldt coast is forecast to have a
southerly reversal tonight through Saturday morning with gusts o f
10-20kts. Winds and seas ease further Sunday into early next week as
a long/middle period southerly swell mixes with lighter, yet
continued, northerly wind waves early to mid next week.


&&

.FIRE WEATHER...Dry offshore flow (E-NE winds) and above normal
temperatures are forecast to persist through this weekend. Gusts
from 25 to 40 mph are expected tonight and into Saturday over the
higher terrain areas of Del Norte and windier ridges of far
northern Humboldt. The offshore winds should diminish on Sunday,
but the dome of warm/dry air will likely stick around through
early next week. In addition to hot weather, very dry relative
humidities are expected for interior Humboldt, Del Norte and
Trinity Counties. Relative humidities are forecast to be in the
teens today through the weekend and into early next week. ERC`s
are forecast to rise sharply while 100hr and 1000hr dead fuel
moistures plunge. This will need to be watched closely for
possible headlines or warnings.

Hot and dry weather will likely continue early to mid next week
for the interior - mostly Trinity County. Coastal areas should
moderate more quickly with the return of a shallow marine layer
and coastal low clouds and fog late this weekend and early next
week.



&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Heat Advisory from 9 AM to 10 PM PDT Saturday for CAZ102-
     105-107-110-113.

     Heat Advisory from 9 AM Sunday to 1 AM PDT Monday for
     CAZ102-105-107-113.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 11 PM PDT Saturday for PZZ450.

     Small Craft Advisory until 8 PM PDT this evening for PZZ455.

     Gale Warning until 11 PM PDT Saturday for PZZ470.

     Gale Warning until 3 PM PDT this afternoon for PZZ475.

     Hazardous Seas Warning until 3 PM PDT Saturday 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.

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