Smith River, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

613
FXUS66 KEKA 042214
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
230 PM PDT Mon Aug 4 2025

.SYNOPSIS...General warming trend is expected for the remainder
of this week. HeatRisk will increase Friday through Monday.

&&

.DISCUSSION...

Dry upper trough will remain over the forecast area through much
of this week resulting in stable dry conditions with temperatures
near seasonal averages. High temperatures are forecast to increase
most substantially on Tue (compared to today). A few more degrees
of warming are expected on Wed and Thu as 850mb temps warm and
onshore breezes diminish. Another dry shortwave trough around mid
week may enhance westerly to northwesterly breezes across the
interior valleys and ridges, particularly in Lake and eastern
Trinity Counties.

A massive 500mb height anomaly will begin to build toward the
Northwest CA coast on Friday as dry offshore flow develops. 850mb
temperatures increase 5-10F above normal and then hold through
weekend. Deep column of warmer air coupled with an offshore flow
will likely propel high temperatures well above normal for the
interior and possibly for the North Coast. Mendocino coast may
end up getting a southerly wind reversal and stratus during the
weekend. Shallow marine layer may keep the Mendo coast from warming
up and if anything temps may not exceed the lower 60s.

Widespread moderate HeatRisk is forecast Friday through Monday,
primarily for the interior. NBM 90th and 99th percentile max temps
(108-114F degrees) for Trinity, NE Humboldt and Del Norte over
multiple days may yield much greater HeatRisk than moderate.
Potential for extreme heat and multiple days of very hot weather is
possible. Stay tuned for updates. For now we will message the
upcoming heat wave on social media and a weather story.

&&

.AVIATION...

04/18Z TAFs...Stratus along the North Coast cleared out with the
daytime heating. VFR conditions have prevailed across all terminals.
Afternoon winds will be mainly from NW at around 10 kts, with
occasional higher gusts...especially at UKI. Winds are forecast to
be lighter and variable after 04Z. Coastal stratus will return
late this evening and bring MVFR ceilings to the coastal terminals,
with brief periods of IFR ceilings possible into Tuesday morning.
/ZVS

&&

.MARINE...

Northerly winds have started to diminish across the coastal
waters. Gentle to fresh breezes are generally expected with the
strongest winds downwind of Cape Mendocino through early Thursday.
The waves are expected to continue to be mainly wind-driven in
response to the local winds. A small long-period southerly swell
around 1-2 foot will likely continue to moves across the waters
through tonight. A mid-period NW swell around 2 feet at 14
seconds will arrives on Tuesday, and then build to 4-6 feet at
10-11 second on Wednesday and continue into Thursday.

High pressure will begin to build in on Thursday, tightening the
pressure gradient Thursday evening into Friday. This will result
in moderate to strong northerly winds, with the strongest winds
across the outer waters. There is a 60-80% chance for gale force
gust across the outer waters Thursday evening, with increasing
chances into Friday. Over the weekend, the strongest northerlies
are forecast to shift into the northern outer waters. /ZVS

&&

.FIRE WEATHER...

Gusty westerly to northwesterly diurnal winds and low daytime
RH`S will yield elevated to locally critical conditions in
Trinity, Mendocino and Lake Counties again this afternoon and
evening. Overlay of highest wind gusts with lowest RH`s is
forecast in southern Lake, SE Mendocino and eastern Trinity
counties. Overnight recoveries should continue to remain good,
however higher elevations that extend into the thermal belt will
continue to have poorer recoveries and gusty winds.

Diurnal breezes are forecast to diminish on Tuesday, however RH`s
will remain low. Another dry cold front will track across the
Pacific NW Wed through Thu and may induce another uptick in diurnal
westerly to northwesterly breezes. These gusty winds coupled with
low RH`s may yield elevated to locally critical conditions again in
the typically dry and wind prone portions of our forecast area;
eastern Trinity, SE Mendocino and Lake Counties.

Dry offshore flow and triple digit heat is forecast for the latter
portion of the week and next weekend in the interior. Magnitude
and duration of the heat remains uncertain. Current indications
are for the strongest offshore winds to occur over the mountains
of Del Norte County and windier ridges of Humboldt County.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
None.
&&

$$

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