270
FXUS66 KEKA 261935
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1235 PM PDT Wed Aug 26 2026

.KEY MESSAGES...

* Interior areas continue to see near to slightly below normal
  temperatures through this weekend.

* Coastal areas continue to see overnight stratus with afternoon
  clearing.

* Tropical moisture may bring a few showers to Mendocino and Lake
  Counties Friday morning.


&&

.SYNOPSIS...Generally mild, seasonable weather continues today and
Thursday. Tropical moisture arrives to the area Thursday night
and Friday, bringing a slight chance for rain showers to
Mendocino and Lake Counties.


&&

.DISCUSSION...An upper-level trough remains in place over the
Pacific Northwest. This has moderated interior temperatures with
highs in the high 80s to low 90s for most interior valleys. A weak
marine inversion in place has allowed for coastal stratus to clear
into the afternoons, but stratus will likely reform each evening
and continue overnight for the coming days. Coastal high
temperatures are forecast to be in the low to mid 60s as
northwesterly afternoon breezes return. A deep marine layer also
brings overnight stratus farther inland, which is moderating some
fire weather concerns, especially closer to the coast.

Thursday into Friday, moisture from the remnants of Tropical
Storm Iselle, currently off the coast of Mexico, will arrive to
central and northern California. Models are coming into better
agreement on the position and timing of the moisture.
Precipitable water values hover around 0.8" to around 1.0". Dry
lower levels will limit potential for any of this to reach the
ground, but a few sprinkles are possible in southern Mendocino
and Lake Counties Friday morning and early afternoon. Instability
is limited and thunderstorm chances are low (less than 5%). That
said, there are a couple models that do show stronger cells with
slightly more instability, so thunderstorm chances are nonzero
but still very low. Recent model runs have moved this moisture
plume to be in a more north-south orientation, which is also
limiting moisture coverage over the area in general and also
limiting moisture to from Thursday evening to Friday morning. By
Friday afternoon, moisture moves eastward. This will be watched
closely as any increase in instability could bring more confidence
in thunderstorms.

This weekend, a trough in the Pacific Northwest rebuilds and is
modeled to be slightly stronger and farther south. This will
continue the moderated interior temperatures (high temperatures
in the 80s to low 90s), and possibly bring coastal drizzle
overnight and more persistent coastal stratus into the
afternoons. Coastal high temperatures are also forecast to drop
into the high 50s to low 60s with this more cloudy pattern. Early
next week, a stronger trough drops from the Pacific Northwest.
This is expected to bring cooler temperatures across the area with
most interior areas 5 to 10 degrees below average. Coastal
drizzle or light rain is possible for the Humboldt and Del Norte
Coasts as well, but recent model runs have been trending this
moisture northward. /JB


&&

.AVIATION...18Z TAFs.A weakened inversion allowed the stratus to
clear out and VFR conditions to take hold by Wednesday morning.
Winds will be generally light, with occasional gusts from afternoon
northwesterly winds. Marine stratus currently observed offshore will
spread back over the coast overnight. Similarly to the previous 24
hours, ceilings will lower to IFR and LIFR levels late Wednesday and
into Thursday, with some periods of fog possible. VFR conditions
will remain inland.


&&

.MARINE...Light winds continue today outside of breezy northerlies
in the lee of Cape Mendocino. Outside the lee of the Cape, seas are
dominated by a mid period southerly swell at around 3 to 4 ft.
Though winds will be generally lighter for the nearshore waters south
of the cape, steep seas of 6 to 8 ft will likely periodically
propagate in. Northerly winds increase Thursday through Friday with
widespread gusts of 20 to 30 kts likely for the outer waters. The
northerlies further strengthen through the weekend, with near
gale to gale conditions likely. JJW/JB


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 PM Thursday to 9 PM PDT Friday
     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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https://www.weather.gov/images/eka/zonemap.png