613
FXUS66 KEKA 180713
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1213 AM PDT Fri Sep 18 2026

.KEY MESSAGES...

* Warmer and drier interior temperatures into the weekend with highs
  in the 90s by Sunday.

* A shallow but strong marine layer forming close to shore with
  persistent marine clouds.


&&

.SYNOPSIS...A blanket of stratus will encroach on the coast
overnight into Friday signaling cool, moist conditions will prevail.
Warmer and drier conditions will rebuild this weekend with shallow
but persistent marine air along shore.


&&

.DISCUSSION...A high pressure ridge will gradually rebuild
Friday and into the weekend. This pattern will allow for interior
temperatures to dry back out and warm back into the 90s. Moderate
north winds will return near shore, helping form a shallow but
persistent marine layer especially north of Cape Mendocino. High
pressure will most likely persist through next week. Most models
show weak to moderate high pressure, but about 20% of ensemble
members show unusually strong high pressure around next Tuesday
that could push interior highs closer to 100. There is near 0%
chance of wetting rain for the next 10 days. /JHW


&&

.AVIATION...High pressure reforming along shore has helped reinforce
a much more expansive and resilient marine layer. This has lead to
mostly IFR ceilings gradually lifting to MVFR for both KACV and
KCEC. There is a 50% chance of LIFR ceilings overnight which
increases closer to dusk at near 70% probability for the coastal
terminals. Mos guidance and GFS are signaling lower visibility
during this time frame as well with NBM giving 60-65% probability of
less than 1/2mile during the early morning hours overnight. Area
profilers are also showing a the marine layer being squished by the
incoming ridge and soundings also show low level inversions after
11am Friday so expect reduced flight categories during the daytime
hours. KUKI could get advected stratus if the layer is deep enough
during the early morning hours. As of 6z, stratus has halted just
east of Comptche but could make its way into the Ukiah valley.
/EYS


&&

.MARINE...Moderate southerly winds have persisted close to shore
through the day with some north winds in the far outer waters. Short
period seas have now generally dropped below 6 feet. Moderate to
strong northerly winds will gradually return to the southern waters
by Friday and gradually spread north through the weekend, though
winds will most likely remain much calmer closer to shore. Short
period wind waves will dominate the marine environment with only a
very minor southwest mid period swell up to 2 feet to speak of. /JHW


&&

.FIRE WEATHER...The thunderstorm risk has ended. New starts will
continue to be slow to spread thanks to otherwise cool and moist
conditions. A building ridge will bring much drier and hotter
conditions through the weekend, but winds will remain gentle and
terrain driven. /JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 9 PM this evening to 9 PM PDT
     Saturday for PZZ455.

     Small Craft Advisory from 5 PM this afternoon to 9 PM PDT
     Saturday 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