508
FXUS66 KEKA 232105
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
205 PM PDT Thu May 23 2024

.SYNOPSIS...Near to below normal temperatures continue in the
interior, especially in the early mornings. Dry, clear skies today
will diminish tomorrow as a trough moves through Friday.


&&

.DISCUSSION...Chilly temperatures this morning have warmed up to
near normal high temperatures. Lingering stratus last night has
lifted. Northerly breezes are anticipated to ease early this evening
along the coast, giving way to light westerly and southerly breezes
bringing the stratus back to the coast.

Clear skies and dry weather associated with a ridge aloft will bring
the potential for a chilly morning in the interior valleys of
eastern Humboldt and Trinity counties, though temperatures will be a
few degrees warmer than last night. The coastal areas will be much
warmer than last night as the influence of stratus will prevent
radiational cooling. Stratus is expected to diminish in the
afternoon hours Friday.

A weak shortwave moving through on Friday will bring more moisture
into the area, with at the very least clouds if not some drizzle or
light rain. HREF has the chance of measurable precipitation along
the coast at 80%, with also high probabilities over the higher
terrain, especially in the King Range and Trinity Alps. NBM
probabilities are more pessimistic, but model soundings do point to
some widespread moisture indicative of drizzle, perhaps even into
the interior.

A ridge will build back in Sunday and into the early week, warming
temperatures back up in the interior to 5 to 10 degrees above
normal. The coast is unlikely to receive the warming trend as the
ridge will strengthen the marine inversion which will continue the
threat of stratus. Ensembles are beginning to converge on a trough
mid-week moving through the Pacific Northwest, which is largely
constrained to the north of California, but NBM does show a low
chance of some light, measurable precipitation reaching us. There is
greater uncertainty on the overall pattern late next week as
ensembles begin to diverge. JB


&&

.AVIATION...Skies are clear across the area this afternoon aside
from a few high clouds. The HREF is showing a 70 percent chance of
IFR ceilings coming in by 07Z at KACV. Probabilities increase later
in the night. There is some uncertainty on how low these ceilings
will come in. For now have them starting in the MVFR category and
quickly dropping to IFR. This may need to be adjusted as it get
closer and is potentially sampled by nearby Metars. This doesn`t
look like it will make it as far inland as KUKI at this point, but
it will make it into many of the river valleys closer to the coast.
The next question will be how much clearing there will be at the
coast Friday afternoon. It looks like it will push back towards the
coast and the coastal airports may see intermittent clearing and
lifting ceilings. It looks like this clearing will be fairly brief,
but ceilings may lift into MVFR. Winds will be lighter than today.
MKK


&&

.MARINE...Winds have started to diminish this morning and will
continue to diminish this afternoon and tonight. These winds as well
as the seas do look like they will diminish slower than previously
expected so have extended the small craft advisories for some of the
zones. The winds are expected to be the lightest Friday in the
middle of the day. The northern waters should see a period of 5 to
10 kt north winds while south of Cape Mendocino will see winds drop
to 10 to 15 kt. In addition to the wind driven seas there is a
northwesterly swell around 3 to 5 feet at 11 seconds. This is
expected to diminish tonight and combine with the diminishing wind
wave. There is also a small southerly wave as well around 2 feet at
15 seconds.

Winds will increase again Friday night and Saturday These winds are
expected to persist around 15 kt in the northern waters and around
20 kt in the southern waters. These speeds are expected to remain
fairly persistent through Monday. The models are generally showing
increasing winds mid to late in the week. Waves will be mainly wind
driven until late Sunday. A small southwest wave of 2 feet at 15
seconds and a small northwest wave of 3 feet at 10 seconds moves in
on Sunday night and Monday. Heights and periods gradually diminish
with both these waves into Tuesday. MKK


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT Friday for PZZ455-475.

     Small Craft Advisory until 9 PM PDT this evening for PZZ470.

&&

$$

Visit us at https://www.weather.gov/eureka

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

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