McKinleyville, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

045
FXUS66 KEKA 302153
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
253 PM PDT Wed Apr 30 2025

.SYNOPSIS...Warm, dry, and calm weather will persist across the area
through Thursday. Light rain and cooler weather this weekend.


&&

.DISCUSSION...

KEY MESSAGES:

-Hot and dry weather building across the interior through Thursday
with highs in the mid 80s.

-Regular, shallow diurnal marine layer right along shore, becoming
strongest around Friday.

-Cooler weather and light rain for the northern half of the area
this Wednesday.


WEATHER PATTERN OVERVIEW: An upper level ridge has continued to
build over the area today. Clear skies and high pressure has allowed
for strong warming across the interior with the hottest location
reaching near 90 this afternoon. Receding marine influence has even
allowed for clear skies along the coast though afternoon sea breeze
has kept conditions much cooler. Some cumulus has built up around
Lake County though moisture currently seems to low to support any
shower development this evening (less than 5% chance). Hot and dry
conditions will peak tomorrow before high pressure begins to break
around Friday. This will mean interior highs will again peak near 90
Thursday. Winds turning more onshore will also promote a stronger
marine layer along shore Thursday and especially Friday.

A narrow trough and surface low will skate down the coast early
Saturday. At the very least, this low will bring thick cloud cover
and much cooler and more moist conditions with highs in the mid 50s.
There is potential for wetting rain across the area though any rain
will be light. Most likely rainfall for the northern half of the
area will be 0.1 to 0.25 inches over 24 hours with just a trace
amount of rain further south.

The vast majority of model ensemble members show weak ridging and
high pressure returning Sunday through mid next week with another
trough setting up for later in the week. Gusty north wind will
return along shore particularly Sunday afternoon.

FORECAST CONFIDENCE AND DEVIATIONS: There is relatively little
uncertainty in the overall forecast. In the short term, the greatest
uncertainty would likely be associated with the strength of the
marine layer on Thursday, though impacts (outside of aviation) will
be minimal.

In the mid term forecast, precipitation this weekend is the area of
greatest uncertainty. The vast majority of models show only very
light precipitation with 30% showing even no more than a trace
around Humboldt Bay. A very small contingent (10%) shows some
potential for rainfall over 0.3 inches along the North Coast. About
20% of models show rain starting late Friday night but essentially
all models show rain staring by sunrise on Saturday and then
tapering off into the afternoon. /JHW


&&

.AVIATION...Most areas observed SKC today. However, coastal marine stratus
developed overnight and was limited to the Humboldt Coast...and
extended across numerous cool river valleys. Stratus lingered just
along the ACV airport coast til around noonday, with Cig/Vis dipping
into IFR during the latter morning. The tight pressure gradient
began to cause winds to rev up at CEC around 9 AM (16z). Coastal
winds elsewhere were mild-breezy. HREF and other model guidances
indicated that the stratus layer would return to the coast
overnight/early Thursday morning as winds diminish overnight.
Stratus will likely be more widespread, bringing MVFR to IFR
conditions to both coastal terminals. /TA


&&

.MARINE...Northerly winds continue across the waters this
afternoon. Tonight and Thursday winds start to diminish as an upper
level system starts to move into the area. Thursday night into
Friday these winds continue to diminish and may briefly go
southerly. Waves will mainly diminish with these winds, However
there is some a small southerly swell. currently it is around 3 feet
at 15 seconds. There is also a northwest swell of 3 to 4 feet at 10
seconds.

Friday night high pressure builds in quickly behind the front
boundary and northerly winds quickly increase again. There is still
some uncertainty on exactly what time these winds will increase, but
it will likely be either Friday evening or overnight. Gale force
gusts are expected by Saturday afternoon in the southern waters with
widespread gales by Sunday morning. Models are in pretty good
agreement on a period of 35 to 40 kt winds. Monday winds are
expected to diminish slightly, but gale force gusts are expected to
linger. Winds will continue to diminish on Tuesday and Wednesday. MKK


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 11 AM PDT Thursday for PZZ450-
     455.

     Small Craft Advisory until 9 PM PDT Thursday for PZZ470.

     Small Craft Advisory until 4 AM PDT Friday for PZZ475.

&&

$$

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png