618
FXUS66 KEKA 240807
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
107 AM PDT Sun Aug 24 2025

.SYNOPSIS...Hot and dry weather will slightly ease Sunday as
building interior moisture begins to create a chance of dry
thunderstorms over interior mountains through early this week.


&&

.DISCUSSION...High pressure will generally continue to
persist over the are Sunday, but midlevel moisture and high clouds
streaming over the area will provide just enough coverage to
slightly cool interior conditions into the upper 90s. Very shallow
marine influence will continue to hang along the coast with highs in
the 60s.

Monsoon moisture will continue to stream up the Sacramento Valley
today with a cutoff low stalling of the Central California COast
helping to curve moisture west over the coastal mountains. The vast
majority (80% chance) of convective models show thunderstorms
staying just north and east of the area today over the Klamath
Mountains. Moisture will gradually pull further south this week.
With a strong signal (70% chance) of scattered thunderstorms over at
least Trinity County by Monday afternoon. Storms will likely be
mostly dry with gusty outflow winds up to around 50 mph and threat
for new fires. Within storm cores, however, up to around 0.4 inches
of rain could be possible, though precipitable water is generally
meager. Models suggest thunderstorm coverage could further expand
further south on Tuesday into Mendocino and Lake Counties, thought
this potential remains uncertain (30% chance overall).

Monsoon moisture will gradually push back out of the areas after
Wednesday with a series of troughs most likely to return across the
Pacific Northwest. Such a pattern will promote a return to much
cooler and more moist weather with marine influence pulling inland,
though the chance for any rainfall currently appears moderate with
about a 20% chance of wetting rain near shore around September 1st.
/JHW


&&

.AVIATION...24/06Z TAFs...Prevailing LIFR conditions at the coastal
terminals, with low ceilings around 200 feet and vsby variations in
FG/BR. Expect vsby drop to quarter mile (1/4SM) in fog early Sunday
at KACV. Low clouds are expected to gradually erode back to the
coast throughout the day on Sunday, but stratus will be stubborn to
scatter out nearshore and at the coastal terminals again.

For inland areas: VFR conditions with mid to high level clouds is
expected to persist across the interior areas through the period,
including in KUKI. Although, some vsby in haze is possible at KUKI
Sunday morning due to the active wildfire in Napa County. MVFR
conditions with skies obscuration and vsby in HZ/FU are likely for
much of Lake County through early Sunday evening, before the wind
shift to SW and push the smoke to NE. Surface winds calm, becoming
SSE at 5-10 kts after 20Z./ZVS


&&

.MARINE...No significant changes. Gentle to moderate northerly winds
persist across the coastal waters this weekend, with lighter winds
nearshore. Seas continue to gradually subside through the weekend. A
small southwest swell around 15 seconds is forecast to persist
through Monday morning. Northerlies increase again Sunday night
through early next week, with moderate to fresh breezes across the
outer waters. Gusts of up to 20-25 kts are possible by Monday
with steep seas rebuilding of up to 8-10 ft. /ZVS


&&

.FIRE WEATHER...Hot and dry weather will very slightly ease today,
though temperatures will remain in the upper 90s with RH in the mid
teens. That said, lagging fuels will continue to respond to very dry
weather form the past couple of days, helping to maintain enhanced
fire weather conditions.

Upper level monsoon moisture has already begun to move up the
Sacramento Valley as evidence by abundant high and midlevel clouds
across the area. That said, any storms that do form today would most
likely be north and east of the Trinity Alps. Storm coverage will
likely increase and move south Monday and Tuesday afternoon as
moisture and pulled over the coastal mountains. Lightning on dry
fuels will bring a high risk of new fire starts even if wetting rain
falls within storm cores. Gusty outflow wind form storms may also
encourage increased fire spread. /JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Fire Weather Watch from Monday afternoon through Monday
     evening for CAZ283.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 11 PM this evening to 3 AM PDT
     Tuesday 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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https://www.weather.gov/images/eka/zonemap.png