Petrolia, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

198
FXUS66 KEKA 152142
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
242 PM PDT Tue Apr 15 2025

.SYNOPSIS...A return of stratus will bring cooler temperatures to
the coastal areas. The cooling trend is expected to continue
through Thursday. There is a slight chance for thunderstorms over
the interior mountains today and Wednesday. Sunny skies and breezy
conditions are expected late week.


&&

.DISCUSSION...An upper level low off of southern California has
brought a deep marine layer to the area with widespread stratus
along the coastal areas. This pattern is expected to continue
tonight, with stratus likely to reach the coastal areas and the
interior valleys of Mendocino once again. Increased moisture and
daytime heating has allowed for a few cumulus clouds to pop up in
the Yolla Bollys early this afternoon. Models vary on instability,
but an isolated shower and thunderstorm can`t be ruled out in
northern Lake, eastern Mendocino, and eastern Trinity counties.
Models are in agreement of a drier airmass moving through
tomorrow, which will likely inhibit further thunderstorm
formation. Instability decreases as well, but not significantly,
so an isolated shower or thunderstorm is still possible. There is
better confidence in Mendocino and Lake as there might just be
enough moisture during the peak heating of the afternoon, but
confidence is still low.

Thursday and Friday additional shortwaves moving down from the north
bring cooler air and breezy winds. Overnight these will become
more offshore and could disrupt the coastal clouds off the coast.
Frost isn`t out of the question in the coldest valleys in Trinity
county, but NBM has probabilities less than 20%.

High pressure is expected to build over the area once again on
Saturday, however the ensembles clusters are showing different
solutions as to how strong this will get. Then on Sunday most of
the clusters are showing a shortwave moving down from the
northwest and bringing cooler air. At this point it still looks
dry. JB/MKK


&&

.AVIATION...Visible satellite imagery showed stratus clouds covering
much of the coastline this afternoon. IFR ceilings will most likely
continue at coastal terminals through the remainder of the day.
There is a 30-50% for conditions to improve to MVFR with ceilings
around 1000-1500 feet late this afternoon, before IFR conditions
return this evening. Confidence in vsby obscurations of 1SM or less
in mist or fog for this evening is not high. HREF continues to
indicate about a 20-30% chance this evening increasing to 50%
overnight. A moderately deep marine layer coupled with southerly
winds will likely result in MVFR ceilings at KUKI by late evening,
followed by IFR ceilings early Wednesday or 16/10Z. DB


&&

.MARINE...Gale force northerlies and very steep northerly waves
are forecast to increase tonight through Wednesday over the northern
outer waters after the passage of a relatively dry cold front.
Chance for gale force northerlies (35-40kt) is forecast to expand
into the northern inner waters Wed afternoon and evening, primarily
near and downwind of Pt St George. A few gusts to 50 kt are possible
(20% chance) as a thermal trough takes shape nearshore. Very steep
northerly waves are forecast to build over the northern outer waters
tonight, and peak around 15 kt Wed afternoon and evening. These
steep waves will spread into the southern waters outer waters and
northern inners Wed afternoon and evening, and probably persist into
the overnight hours. Hazardous watch in these areas have been
upgraded to a warning. Very steep waves will likely persist on Thu
before winds and seas trend downward by Friday. Northerlies and very
steep waves will most likely ramp up again over the weekend after
passage of another dry cold front. DB


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 9 AM to 4 PM PDT Wednesday for
     PZZ450.

     Hazardous Seas Warning from 4 PM Wednesday to 3 AM PDT
     Thursday for PZZ450.

     Small Craft Advisory until midnight PDT tonight for PZZ470.

     Gale Warning from midnight tonight to 3 AM PDT Thursday for
     PZZ470.

     Small Craft Advisory until 3 PM PDT Wednesday for PZZ475.

     Hazardous Seas Warning from 3 PM Wednesday to 3 AM PDT
     Thursday for PZZ475.

&&

$$

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https://www.weather.gov/images/eka/zonemap.png