Hidden Valley Lake, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

418
FXUS66 KEKA 052131
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
231 PM PDT Sun Apr 5 2026

.SYNOPSIS...Above normal warmth is forecast to continue early next
week in the interior and then trend cooler later in the week. Chance
for showers and interior thunderstorms will arrive on Wednesday
and continue on Thursday and Friday.

&&

.DISCUSSION...Visible satellite imagery showed stratus and potential
fog building offshore over the outer coastal waters this afternoon.
Mesoscale model ensemble (HREF), BUFKIT time-height sections of
temperature and humidity as well as model output statistics all
point to a return of stratus and fog tonight into Monday morning for
coastal land areas. Typically, after a warm up in the interior
and along the coast, stratus and fog will come back hard with low
visibilities of 1/4SM or less. HREF chances for dense fog are
around 30-50% later tonight and Monday morning. Some areas of
dense fog are possible by early Mon. The shallow marine layer and
stratus should clear out in the afternoon on Mon, but areas of
fog and low cloud may linger near or meander about near the shoreline
through the day as winds remain light and variable. Precipitation
chances are minimal Mon through Tue, though spats of coastal
drizzle or a few sprinkles over the mountain tops are possible.

Otherwise, dry weather and above normal high temperatures are
forecast to prevail across the interior through at least Tuesday
as a ridge aloft springs back up after the passage of a weak
transient wave embedded in southwesterly flow aloft. Above normal
500mb heights and 850mb temps may even last into the end of the
week. High temperatures may not cool down much in the interior.
Marine air and low clouds pushing into the coastal river valleys
could also bring significant cooling around mid week if northwest
winds increase offshore over the waters.

Precipitation chances return around mid-week (Wed) as a cut-off
low centered near 35N and west 140W slowly burrows eastward into a
dominant ridge. NBM and WPC have slowed down the arrival of the
highest precip chances and amounts til Thu. Overall not much rain
is expected over 3 days (Wed-Fri), generally less than 0.25 inches
with locally higher amounts due convection in the interior.
Potential for interior convection/thunderstorms increases as early
as Wed with long CAPE profiles around 150-300j/kg, lifted indices
near -1C and PWATS over 200% of normal in the afternoon/early
evening over eastern Trinity, NE Mendo and northern Lake where low
level convergence of upslope winds occur. Wrap around moisture
with above normal precipitable water (PWATS > 200% of normal) and
greater CAPE Thu and Fri should yield stronger storms that may
result in heavy downpours and perhaps some small hail. Profiles
are not too favorable to strong and gusty outflow winds
(inverted-V profiles), however a few deterministic models, namely
the ECMWF, indicate higher surface-to-500mb S-SE bulk shear around
35-40kt and strong multi-cell storm clusters seem possible in the
interior.

Beyond Fri into next weekend, wrap around moisture with interior
showers and thunder remains possible on Fri and Sat if the
eastward progression of cut-off low slows down or stalls over the
area. Another trough may come barreling down from the NW bringing
considerable cooling and perhaps more light precip. Or the ridge
will come back and leave the area in dry stable weather with a
warm up for the interior.

&&

.AVIATION...VFR conditions at all terminals through the day. Inland
terminals to experience up-valley/up-slope, terrain-driven winds
through the daylight hours. This evening, there is moderate to
high probabilities of coastal stratus developing along the North
Coast. This could set in between 03-06Z with a chance (20-40%) for
fog development by 08Z. Expect IFR to LIFR categories from this
evening through the monring as models show this cloud deck
persisting through the 04/06/1800Z. Inland remains VFR through the
TAF period. DS

&&

.MARINE...Weak atmospheric forcing over the coastal waters will keep
winds light (<10kts) today through Tuesday. Beginning Tuesday, a
surface low pressure center currently at ~145W will finally have
moved close enough to force northerly winds. There remains uncertainty
as to how strong these winds will be, as it depends on where this
low pressure center ends up off the coast of California. As for
right now however, the outer waters can expected winds between
10-20kts and the inner waters can expect winds between 5-15kts
from Wednesday through the end of the week. The higher end of
these winds could produce steeper seas.

In terms of swell, expect a small, long period swell through the
coming week. Today through Wednesday a small, short-to-mid period
swell out of the NW. The sea state later in the week will be
dominated by the waves from our developing northerly winds. DS

&&

.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.

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