831
FXUS66 KEKA 032058
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
158 PM PDT Sun Aug 3 2025

.SYNOPSIS...Interior thunderstorms around the Trinity Horn will
be of particular interest through the day and into the evening.
Ridging into this coming week will warm temperatures with
potential for another trough next week.


&&

.DISCUSSION...Cooler temperatures and continuing convective
weather bring us into early August. Most of the convection will be
isolated to the Trinity horn today as convective models highlight
a more severe set up towards Siskiyou and northeast towards
Oregon. Timing has been consistent but models recently have pushed
location to the northeast of our CWA. The Trinity horn is most
likely to get convection today as CAPE, moisture, and
southwesterly flow favor activation. CAPE and moisture have also
been isolated to the Trinity horn with modest values in the
latest run of the HRRR and NBM around 700 j/kg, tapering off by
02z. The culprit of the continuous reoccurring convective
afternoons is a series of shortwaves and troughs along with
monsoonal moisture. This will be interrupted as the work week
progresses, likely seeing a warm up beyond seasonal norms by
Friday and Saturday according to the EFI. ECMWF also shows 594dm
isobars in the 500mb heights in the following days after the
initial warm up next weekend, which would signal high pressure and
higher temperatures. A possible heat dome will get the region
back into higher temperatures if long range modeling pans out.
This could reverse the effects of what we could call a mild fire
season thus far for our CWA.


&&

.AVIATION...03/18Z TAFs...MVFR ceilings along the coastal
terminals. However, VFR conditions are expected for the coastal
terminal with low cloud mixing and scattering out as northwesterly
winds increase this afternoon. Surface winds from W at around 5kts,
then after 21Z becoming NW at 10-15 kts with higher gusts. Wins are
expected to decouple and become lighter and variable after 04/04Z.
Coastal stratus will return late this evening to bring MVFR
ceilings, with brief periods of IFR ceilings into Monday morning.

For KUKI, VFR conditions are expected to prevail. Breezy NW winds at
10-15 kts are expected to develop after 20Z, with occasional gusts
up to around 25kts. Winds are forecast to decouple after 04Z, and
become light N winds. /ZVS


&&

.MARINE...Locally strong northerly winds continue downwind
Cape Mendocino this afternoon through tonight, with near gale to
gale force gusts. Elsewhere, generally moderate to fresh northerly
winds, with the strongest winds across the southern waters. As
result, Small Craft Advisory remain in effect for zones 455 and 475
through at least Monday afternoon. Seas will mainly be wind driven
and steep around 5 to 7 feet.

Winds are expected to slowly diminish early in the work week before
increasing again by late week. A mid-period NW swell around 2 feet
at 14 seconds are builds on Tuesday. A forerunner NW swell around 4-
5 feet at 12-13 second will traverse the area on Wednesday and
continue through Thursday. /ZVS


&&

.FIRE WEATHER...We will continue to include a headline in the
fire weather forecast for isolated thunderstorms and possible new
ignitions through this evening in Zone 283. One more round of
showers and thunderstorms for the Klamath Mountains (15-25%
probability), mostly around the Trinity Horn this afternoon, is
forecast before an incoming upper level trough/cold front will
change our current weather pattern.

This trough will likely induce stronger westerly to northwest winds
for our typically dry and windy areas; Lake, southern Mendocino and
eastern Trinity. Low daytime RHs in the mid 20% or so and fairly
strong wind gusts for the season due to the trough/cold front
passing overhead and also warrant a headline fore Fire Weather Zones
283, 277, & 264. Southern Lake County and Interior Mendocino show a
60-90% probability for wind gusts over 30mph Sunday afternoon.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT Monday for PZZ455-475.

&&

$$

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