667
FXUS66 KEKA 070708
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1208 AM PDT Tue Oct 7 2025

.SYNOPSIS...Above normal temperatures continue through Tuesday. The
pattern begins to change Wednesday with cooling temperatures from an
approaching trough. Rain chances increase Friday with much cooler
conditions likely.


&&

.DISCUSSION...Offshore flow has contributed to much above normal
temperatures Monday, with 70s to low 80s along the coast. Lighter
offshore will develop tonight with weakening of the thermal trough,
but some of the interior ridges will be breezy. Another mostly
cloudless, full sunshine day forecast Tuesday. Daytime highs will
tick up slightly higher for the interior on Tuesday, while the coast
looks to be slighlty less warm than today with the weaker thermal
trough. A weak shortwave will push into into Central California,
with no impacts other than perhaps some increased cloudcover over
Lake County late Wednesday.

A stronger NE Pacific trough will take shape late wednesday, with
evolution into a closed low Thursday as it drifts south toward N CA.
Cold 500 mb temperatures of -25C and modest surface CAPE upwards of
250 J/kg with the low will bring the chances for thunderstorms and
higher rainfall rates. With the convective nature of this low, exact
rainfall over the entire forecast area. The highest chances are over
the King Range, the ridges of Humboldt and most of Del Norte County.
NBM is showing moderate confidence for general rainfall totals over
1 inch in 24 hours (40-70%). Chances for 72 hour rainfall over 2
inches is strong, around 30-50%, primarily over the higher terrain.
Where these higher amounts are concentrated is still uncertain given
the setup. Interestingly, there are hints of a veering wind profile
over the ocean Friday, and this would point to a waterspout threat.
There may be convective activity that pushes somewhat inland, and
soundings currently support this scenario. Additionally, with how
cold the upper-levels are, snow levels are likely to drop and light
accumulations above 6000 ft in the Trinity Alps and the Yolla Bollys
aren`t out of the question. High temperatures are likely to fall
into the 50s and 60s, with lows into the 30s and 40s for much of the
interior Friday into the weekend. Frost is possible overnight in the
interior areas, especially in Trinity County. The only uncertainty
will be the rain timing and the amount of residual low cloud
cover. A slight jog north or south of the low would change this
forecast, so higher confidence in details will come into focus in
the coming days. JJW/JB


&&

.AVIATION...Mostly VFR/MVFR conditions for much of the
night at the coastal terminals. GFS-MOS guidance is suggesting a
reduction in flight categories by 12z. With minimal cloud cover,
radiation fog would likely be the culprit for a reduction in
visibility but there isn`t much confidence in this happening as
conditions lack ground moisture. TAFs at KACV do have lower
visibility tempo`d just in case. Easterly winds at KACV and KCEC
will keep coastal stratus at a minimum overnight into Tuesday early
morning. Winds veer from the SW by noon Tuesday for the coastal
terminals. Light to calm winds at KUKI through the TAF period with
light northerlies picking up by the late afternoon Tuesday. /EYS


&&

.MARINE...Light and variable winds to 10 kt or less are forecast to
continue overnight. Northerly winds will begin to trend stronger
Tuesday evening through Wednesday. NBM probability for gusts over
30kt increases to 40-50% initially over the outer waters Tuesday
night. These 30 kt gusts will likely (80% chance) expand into
portions of the inner waters on Wed. Primary area for these stronger
corridors of winds inside 10NM will most likely be in the lee of
Cape Mendocino (40-60% chance) and perhaps around Pt St George (20%
chance) during the afternoon and evening. High resolution models may
end up coming in hotter and heavier with northerly winds and a few
localized gale gusts to 35 kt are possible. Steep northerly wind
waves will also rebuild to 6 to 8 ft (significant wave heights) by
Wednesday and seas will once again become hazardous to small
craft.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 6 AM Wednesday to midnight PDT
     Wednesday night 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