922
FXUS66 KEKA 210812
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
112 AM PDT Mon Sep 21 2026

.KEY MESSAGES...

* Warm and dry conditions for interior areas through Wednesday.

* A shallow but strong marine layer along shore will weaken over
  the next couple of days with some clearing possible by Tuesday.

* Cold front Thursday into Friday with a 20% chance of light wetting
  rain along the North Coast.

&&

.SYNOPSIS...Warm and dry conditions will persist across the interior
through Wednesday. The coastal marine layer will begin to weaken
today with better clearing expected by Tuesday. A cold front may
bring some light rain to Humboldt and Del Norte counties on Thursday
or Friday.


&&

.DISCUSSION...Low pressure moving into the Central California Coast
will help to ease high pressure over the next couple of days. Dry
and warm conditions will persist through Wednesday across the
interior with varying levels of high level cloudiness across the
region.

Ensemble models have started to show better clarity for the forecast
by late weak. Most show a quickly passing area of high pressure on
Thursday to be followed by a cold front Thursday night into Friday,
helping to drop interior highs into the low and mid 70s for next
weekend. The front will also disrupt and lift any marine layer that
manages to reform on Thursday. Most models still show the front
mostly dry, but now about 20% show very light wetting rain focused
along the North Coast. Weak high pressure is most likely to quickly
rebuild behind the front. Despite the cooler air, there is little
potential (20% or less even for the coldest valleys) for frost
behind the front.

&&

.AVIATION...A strong marine inversion continues to hold coastal
clouds along the coast with IFR to LIFR conditions expected
overnight into Monday morning. Patchy areas of drizzle are possible
in the morning hours. As an area of low pressure spins over
California, light offshore flow on the north side of this low will
likely start to weaken the inversion and bring increasing clearing,
but this may not occur until Tuesday in northern areas at CEC and
ACV. IFR to low end MVFR is likely to persist Monday the two primary
coastal terminals. Farther inland any morning near coast valley
clouds will dissipate in the monring hours leaving VFR through the
day.

&&

.MARINE...Moderate to isolated strong north winds have now built
throughout the outer waters, though condition remain calmer closer
to shore, especially north of Cape Mendocino.  Short period seas
have built in response to the winds with waves over 8 feet in the
outer waters and some steep seas up to 6 feet migrating into the
inner waters. Similar winds will persist for the next several days
and even strengthen in the southern outer waters with some near gale
conditions by Tuesday morning. Winds will gradually weaken form
north to south mid to late week as a cold front approaches. Short
period wind waves will continue to dominate the environment
alongside a very minor southwest swell. /JHW

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT Wednesday for PZZ455.

     Small Craft Advisory until 9 AM PDT Wednesday for PZZ470.

     Small Craft Advisory until 9 AM 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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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png