929
FXUS66 KEKA 282101
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
201 PM PDT Wed Oct 28 2026

.KEY MESSAGES...

* Dry weather is expected this afternoon through Friday. 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
  the weekend.

* 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 build 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 ended up
slightly above forecast, especially in interior Humboldt and
Trinity, as extensive valley clouds filled in. Cloud cover is
expected to diminish tonight outside the near-coast river valleys
with a similar to slightly colder night possible. Cold nights
continue for the coming days with chances for frost and near-to-
below freezing temperatures possible for the interior valleys, and
even close to the coast. The troughing pattern remains in place for
the remainder of the week, but conditions remain dry through Friday.
Onshore flow will most likely help a weak, diurnal marine layer
reform, especially around Humboldt Bay, as soon as Wednesday night.

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%. 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. This pattern
will continue to be watched over the coming days. Stay tuned! /JB


&&

.AVIATION...(18Z TAFs)...VFR conditions are being observed at all
terminals early this afternoon with interior valley clouds quickly
dispersing. Weak offshore flow is expected to hinder a widespread
return of marine clouds tonight. Still, some models do show a deep
marine layer returning in areas tonight, with around a 30% chance
for MVFR ceilings at CEC and ACV. Chances are higher around Humboldt
Bay and over the Eel River delta. Some interior valleys may see some
intrusion of clouds again tonight, however this will be less
widespread than this morning. /JB


&&

.MARINE...Strong northerly winds have built into the southern outer
waters with gusts near gale force. Winds will remain strong and
intermittently push into the inner waters through Thursday evening.
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 from 1 AM to 9 AM PDT Thursday for
     CAZ101>106-109-112.

     Coastal Flood Advisory until 3 PM PDT this afternoon for
     CAZ103.

     Freeze Warning from 1 AM to 9 AM PDT Thursday for CAZ110-
     111-114.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Coastal Flood Advisory until 3 PM PDT this afternoon for
     PZZ415.

     Small Craft Advisory until 3 AM PDT Thursday for PZZ455.

     Small Craft Advisory until 9 PM PDT Thursday 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