313
FXUS66 KEKA 290717
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1217 AM PDT Thu Oct 29 2026

.KEY MESSAGES...

* Dry weather through Friday. Light rain chances return over the
  weekend.

* Frost and near-freezing overnight temperatures possible for the
  interior valleys and possibly near the coast each night through
  Saturday.

* Minor coastal flooding at high tide expected through Thursday
  around Humboldt Bay.

&&

.SYNOPSIS...Cool and dry weather is expected through Friday with
additional chances for light rain over the weekend. High tides are
likely to cause areas of coastal flooding for areas around Humboldt
Bay through Thursday.


&&

.DISCUSSION...Dry and cool air continues to stream into the area as
we remain under a troughing pattern. This is bringing near to
slightly below normal temperatures, with most areas seeing highs in
the 50s and 60s. A stray 70 is possible in the warmest valleys of
Mendocino and Lake Counties. Temperatures this morning are again
close to frosty conditions. That said, clouds building from the
south as well as a reforming marine layer will likely inhibit any
widespread frost formation by morning. The troughing pattern remains
in place for the remainder of the week, but conditions remain dry
through Friday. Increasing upper level clouds will likely aid in
particularly cool interior highs barely reaching the 60s. Onshore
flow will most likely help a weak and diurnal marine layer form
through the end of the week.

The only exception to a dry Friday would be in Del Norte County,
where there is roughly a 20% of light rain that currently may only
amount to a hundredth or two with the bulk of precipitation to the
north. This low off the coast of Oregon moves southward this
weekend, though there is some uncertainty on just how much moisture
will arrive and how far south the low will drop. There is a
widespread 30-50% chance of any measurable rain on Saturday and
Sunday for all of NW California. The chance for wetting rain (over
0.1") is around 20% focused on the North Coast. This system is a
cold system, and snow levels may drop to around 4500 to 5500 ft.
Moisture is limited by the time snow levels drop, but a dusting of
snow in the higher terrain may be possible, including along Highway
3 at Scott Mountain Pass.

While over a week out, long range ensemble members are continuing to
signal a shift towards a wetter pattern. Today`s model runs are less
bold than yesterday`s and the highest potential for heavier rain has
moved into late next week and into the weekend. Still, some models
do show some rain mid next week with about a 50% chance for any
measurable rain and a 20% for over a tenth of an inch. Essentially
every day between November 14th and 90th currently show a 30% chance
of wetting rain, suggesting high confidence in a wetter pattern but
high timing uncertainty. This pattern will continue to be watched
over the coming days. Stay tuned! /JB, JHW


&&

.AVIATION...Weak onshore flow and slightly less instability has
allowed for a weak and inconsistent marine layer to form overnight.
This layer will bring a variable 50/50 chance of IFR ceilings to
coastal terminal through sunrise. QUick clearing to VFR is expected
early Thursday morning followed by a slightly stronger marine layer
overnight. Otherwise VFr conditions persist for the interior aside
from some patchy valley fog. /JHW


&&

.MARINE...Strong northerly winds persist in the southern outer
waters with some steep waves up to 8 feet pushing closer to shore.
Winds will remain strong though more isolated to the outer waters
through Thursday night. Short period seas of 8 to 10 ft are expected
with these winds. North winds have remained much more moderate in
the northern waters. North winds will persist until early Friday
when they diminish into the weekend. Beyond short period seas,
various minor mid period westerly swell will augment the sea state
through the week. /JHW


&&

.COASTAL FLOODING...Water levels Wednesday reached 9.12 ft above
MLLW at the North Spit. This brought some minor flooding to low
lying areas of King Salmon and the Arcata bottoms. This was with an
anomaly of about 1 foot above astronomical tides. The surge models
are showing a slightly higher anomaly during the high tide Thursday
(at 1:59 PM), and with an astronomical tide of 7.88 ft, this would
again push levels near or above 9.0 ft. A Coastal Flood Advisory
will be reissued for the high tide on Thursday.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Frost Advisory until 9 AM PDT this morning for CAZ101>106-
     109-112.

     Coastal Flood Advisory from 1 PM to 4 PM PDT this afternoon
     for CAZ103.

     Freeze Warning until 9 AM PDT this morning for CAZ110-111-
     114.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Coastal Flood Advisory from 1 PM to 4 PM PDT this afternoon
     for PZZ415.

     Small Craft Advisory until 9 AM PDT this morning for PZZ455.

     Small Craft Advisory until 9 PM PDT this evening 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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