839
FXUS66 KEKA 301127
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
427 AM PDT Sun Aug 30 2026

.KEY MESSAGES...
* Breezy afternoon winds will elevate fire weather concerns for
  the interior this afternoon.

* Dry, generally mild, seasonable weather continues this weekend.

* Isolated thunderstorms are possible Tuesday afternoon and evening.

* Fall-like conditions possible next week with multiple chances of
  precipitation and cooler temperatures.

&&

.SYNOPSIS...Generally mild, seasonable weather continues across
the area with slightly below normal interior temperatures and
coastal areas seeing overnight stratus. A troughing pattern returns
next week bringing multiple chances of precipitation.


&&

.DISCUSSION...A sunny Sunday is likely across the area as a weak
marine inversion and breezy northwesterly winds clear quickly
scatters any stratus that forms overnight. Interior temperatures
will nudge higher today as mid level heights briefly increase ahead
of the next trough, which is expected Tuesday.

The stratus will deepen again and persist longer along the coastal
areas Monday ahead of a potent midlevel disturbance. Instability has
trended down with this disturbance. Chances for MUCAPE over 100 J/kg
have been reduced to around 10%, primarily in Trinity County and
over the coastal waters. The inconsistency in global models arises
from questions in potential 500-700 mb relative humidity. NBM
maintains 10% chances for thunderstorms mainly for Trinity County,
but perhaps into Del Norte and Humboldt as well. That solution
sounds reasonable at this time, but there are still large
discrepancies and a growing shot for no activity at all. Regarding
fire weather concerns, models do precipitate moisture to the surface
with any potential shower or thunderstorm, but soundings do look on
the drier side for the described interior areas. The higher
instability may progress through with the forcing associated with
the passage of the dynamic shortwave Tuesday night. Guidance has
been trending wetter Wednesday and less unstable Tuesday however.
Regardless, a much wetter environment will immediately follow the
trough.

Confidence is growing on a second colder, wetter system moving into
the Pacific Northwest Wednesday, with additional disturbances to
follow in a well established troughing pattern. The main uncertainty
is how far south this will be positioned, but precipitation
estimates continue to grow, with much of the North Coast at over 50%
chances to receive at least a half inch of rain. Wetting rain
(>0.1") chances are around or above 80% for the North Coast and
around 40-60% for much of the interior outside Lake County. There
are also moderate to high chances for southerly winds to gusts over
25 mph Wednesday with the storm system. This is a ways out, so there
is still plenty of time for this pattern to change, but right now
signs are pointing to fall-like conditions. Regardless of
precipitation, temperatures are likely to fall well below normal.
Chilly morning lows in the 30s and 40s are possible for much of the
interior.


&&

.AVIATION...12Z UPDATE...A weak bank of coastal stratus exists
for the Humboldt Bay are this morning with MVFR conditions. This
is expected to scatter out by mid morning leading to VFR with
strong northerly winds. A return of more widespread cloud coverage
for the coast is expected for Sunday night into Monday morning.
Inland areas will experience VFR with breezy, mainly-northerly,
afternoon winds funneling through the terrain before giving way to
calm, variable winds.


&&

.MARINE...Apart from areas around and south of Point St George,
winds in the inner waters north of Cape Mendocino remain below
advisory level. Gust up to 35 kts can be expected around Cape
Mendocino again this afternoon and evening. Additionally, isolated
areas of gale strength gusts will expand farther into the southern
outer waters. Steep wind driven seas of 7 to 10 ft will develop as a
result, with locally higher amounts in the southern waters around
the cape. These will combine with a long-period south swell arriving
today. The northerlies will begin to quickly subside Monday as a
troughing pattern returns. Seas and winds look to be quite low for
much of next week from the troughing. A stronger front with a round
of increased southerly winds will be possible around mid next week.


&&

.FIRE WEATHER...Somewhat lighter but continued breezy conditions
will continue today with low RH in the twenties to teens. A
southerly wind surge will push through the Sacramento valley Monday,
and winds could be especially breezy over northeast Trinity County.
Westerly winds will be gusty on Monday over much of our interior
while minimum RH and overnight recoveries continue to improve.

A potent shortwave trough will bring a chance for mostly dry
lightning, or a mixture of some wetter showers/storms Tuesday or
Tuesday night. The available mid to lower level moisture to fuel
these storms is still largely in question. There is currently around
a 10 percent chance of the thunderstorm occurrence for mainly
Trinity County Tuesday afternoon. The passage of the shortwave
through Tuesday night may bring additional chances, including
outside of Trinity County. The more moisture rich scenarios bring in
higher level instability, so the situation bears watching at least.
Guidance has been trending wetter Wednesday and less unstable
Tuesday however.

There is second colder system forecast to follow Wednesday and bring
accumulating rainfall over the area. Eastern Trinity County has a 50
to 65 percent chance of a wetting rainfall with this system. Areas
farther northwest will have a good chance of meaningful accumulating
rainfall. Breezy southerly winds are possible Wednesday, which could
be problematic if lightning does occur on Tuesday and little
rainfall follows. The overall environment will certainly moisten up
however. Additional shots of at least light rainfall continue
through late in the week and potentially into next weekend with a
continued troughing pattern.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT this evening for PZZ450.

     Small Craft Advisory until 9 AM PDT Monday for PZZ455-470.

     Small Craft Advisory until 3 PM PDT Monday 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