Alton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

185
FXUS66 KEKA 250710
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1210 AM PDT Sat Apr 25 2026

.SYNOPSIS...Isolated showers and thunderstorms are possible in the
interior each afternoon through Monday. Drier weather returns mid
next week.


&&

.DISCUSSION...Moisture from an upper low off the northern California
coast brought a few showers Thursday afternoon. This upper low is
moving off the coast towards a secondary upper low and will combine
off the central California coast this morning. This positioning of
the low by this afternoon will supply slightly more moisture to the
area compared to yesterday. A few showers and isolated thunderstorms
are possible again in the interior this afternoon, mainly in
northern Lake, eastern Mendocino, and eastern Trinity Counties.
Little rainfall is expected with these storms, with the highest
chance for wetting rain (>0.1") being in eastern Trinity at around
40%. At the coast, the deep marine layer with stratus will likely
continue with only partial clearing, if any, expected. A shortwave
moving through tonight into Sunday morning may bring drizzle to the
coastal areas. This through will continue to bring moisture and
instability to the interior, bringing a chance for afternoon showers
and thunderstorms. Recent model runs show Sunday as having the more
activity than Saturday, but mainly focused in Trinity, interior
Humboldt, and interior Del Norte. Wetting rain chances remain the
highest (30-50%) in Trinity County and much lower elsewhere. The
trough slowly moves out of the area Sunday night into Monday, but
some models are showing an additional shortwave or upper low moving
through the area Monday afternoon. This could provide enough
moisture to continue afternoon shower and isolated thunderstorm
activity. Drier and warmer weather is likely to return by mid next
week as ridging redevelops. JB



&&

.AVIATION...Weaker winds have allowed for a consistent marine layer
to persist all along the coast. At the same time, passing low
pressure has kept the layer lifted with MVFR ceilings around 1.5
kft. Instability in the marine layer may even allow for some drizzle
early in the morning. The marine layer is likely to persist all day
Saturday, though there is some chance (35%) of briefly scattering
out to VFR. Mostly MVFR conditions will most likely persist Saturday
night. Interior conditions are much more uncertain, though MVFR
condition chance will increase (40% chance) in the Russian River
Valley overnight Saturday as low pressure slowly migrates south and
pulls marine air up the valley.


&&

.MARINE...Moderate to strong northerly winds have shunted far
offshore with near calm winds close to shore. Some steep short
period seas have persisted int he outer waters but even those will
decay through the day Saturday. Weak low pressure meandering down the
coast may even promote a weak southerly wind reversal near shore.

Moderate north winds will briefly push back into the inner water
overnight Saturday, very slightly increase seas. Winds will more
consistently weaken for early next week with persistent but gentle
north winds in all waters. Short period seas will dominate the sea
state, but a mid period westerly swell building up to 4 feet will
augment seas through the weekend.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 1 PM PDT Sunday for PZZ470-475.

&&

$$

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