Willow Creek, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

436
FXUS66 KEKA 070829
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
129 AM PDT Thu Aug 7 2025

.SYNOPSIS...Temperatures near seasonal averages expected through
Today. Risk for heat- related impacts increase Friday through
Monday in the interior.


&&

.DISCUSSION...A dry cold front push onshore overnight. This
feature is spreading high level clouds across the forecast area.
Otherwise, a shallow marine layer has developed along the coast
and extended well inland up the adjacent river valleys.

An upper level trough continues to dominate the weather pattern
across the forecast area through today, with near-seasonal, or
seasonable, average temperatures. Interior high temperatures
similar like Wednesday reading, with highs generally in the upper
80`s to mid 90`s. While coastal highs generally in the mid to
upper 60`s. Coastal stratus is expected to mix and scatter out
late this morning with the diurnal heating. In addition, breezy
north-northwest winds of 20 to 30 mph are expected over the
coastal headlands this afternoon as a surface high pressure begins
to build into the area.

A massive 500mb height anomaly will begin to build offshore and
toward the Pacific Northwest on Friday in the wake of the
aforementioned trough. This warm dome of air coupled with dry
offshore wind flow will propel high temperatures 5-10F above
seasonal averages on Friday. The North Coast will probably warm
into the lower to mid 70`s Friday and Saturday. Highest
probability for 70F or more for Eureka is Saturday. A southerly
wind reversal and stratus/fog will most likely keep most of the
Mendocino coast much cooler with highs possibly not more than 60F
along the shoreline. We will post a temperature trend graphic for
coastal and inland areas.

The warm dome aloft will build over the area during the weekend
and interior temperatures will continue on an upward trend.
Widespread moderate HeatRisk is forecast Friday through Monday,
primarily for the interior. NBM means and 50th percentiles are
around 102-107F for many of our hot interior valley spots. NBM
90th percentile max temps range from 108-115F over multiple days
and would yield greater HeatRisk than moderate. Probability of
occurrence is 10-20% for this hotter scenario. NBM probabilities
for 106F or more are 50-80% along the Trinity and Klamath river
valleys Sat-Mon. At the moment it appears heat advisory will be
necessary given the coverage of major HeatRisk for Trinity County
and perhaps NE Humboldt. Stay tuned for updates. We will continue to
message the heat hazard on social media outlets and on our web page
via a weather story graphic.

Deep column of warm/dry air will likely keep temperatures in the
triple digits for mostly Trinity and NE Humboldt into Monday.
Shallow marine air mass should gradually trickle into the river
valleys of Del Norte, western Humboldt and western Mendocinco
Counties Tue-Wed next week for some relief from the heat.






&&

.AVIATION...A shallow marine layer has settled along the coast
overnight, generating very inconsistent conditions as ebbs and flow
along shore. Coastal terminals have varied between LIFR and MVFR
ceilings and visibilities. Highly inconsistent conditions will
continue through early Thursday morning, though LIFR conditions will
become more likely through the night. Most models suggest that the
coast should quickly scatter out in the morning, especially with
increasing northwest winds helping to scour out clouds. /JHW


&&

.MARINE...Currently gentle northerly wind and shallow seas
throughout the waters overnight will not last much longer. High
pressure building over the area will enhance northerly winds
throughout the waters by later Thursday afternoon. Near gale to
gale force gusts will build into the outer waters, with localized
areas of gusts over 40 kts fanning downwind of Cape Mendocino and
Pt. St. George. Steep short period seas will quickly build in
response with seas over 10 feet in the outer waters by midnight
and steep seas over 6 feet building into the inner water by early
Friday where winds are calmer.

North winds will persist into the weekend, but will begin to
slightly shunt offshore by Saturday afternoon. Though near gale
force conditions will likely continue for the northern outer waters,
much calmer conditions will begin to build in the south, especially
near shore around Ft. Bragg. North winds will continue to push out
of the coastal waters early next week. /JHW

&&

.FIRE WEATHER...Generally moderate to good overnight RH
recoveries have been observed, with values from low 40 to mid 70`s
percent across eastern Mendocino, Lake and Trinity counties.
While higher percentage across along the coastal areas and
interior Humboldt and Del Norte counties. Except for some enhanced
north wind along the shore and channeled along the Eel river
valley today, daytime winds will be mostly gentle and terrain
driven.

Dry offshore flow (E-NE winds) and above normal temperatures are
forecast to return tonight into Friday and persist through this
weekend. The offshore winds should diminish on Sunday, but the
dome of warm/dry air will likely stick around through early next
week. Current indications are for the strongest offshore winds to
occur over the mountains of Del Norte County and windier ridges of
Humboldt County Fri-Sat during the night and morning hours. In
addition to hot weather, very dry relative humidities are expected
with interior Humboldt, Del Norte and Trinity Counties in the
teens Friday through the weekend and 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
in the interior - mostly Trinity County. Coastal areas should
moderate more quickly with return of a shallow marine layer and
coastal low clouds and fog late this weekend and early next week.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 11 PM Thursday to 5 PM PDT Friday
     for PZZ450.

     Small Craft Advisory from 11 AM Thursday to 5 AM PDT Friday
     for PZZ455.

     Small Craft Advisory from 8 AM to 11 PM PDT Thursday for
     PZZ470.

     Gale Warning from 11 PM Thursday to 5 AM PDT Saturday for
     PZZ470.

     Small Craft Advisory from 8 AM Thursday to 5 AM 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.

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