457
FXUS66 KEKA 282156
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
256 PM PDT Tue May 28 2024

.SYNOPSIS...A warming trend will kick off this week with the
hottest inland valleys reaching the upper 90s late this week. A
regular cycle of stratus and gusty afternoon onshore flow will
persist for the coast.


&&

.DISCUSSION...An upper level trough is evident passing by NW
California this afternoon, allowing for all morning stratus to
easily clear out from a weakened marine inversion. High resolution
models hint at the lift causing some isolated coastal drizzle
tonight, but even the most aggressive models show nothing more than
trace accumulation. Otherwise, the trough has had little impact
beyond some enhance fair weather cumulus over interior mountains.

All models show high pressure building in through Friday. This will
bring hot temperatures back to the interior with NBM even showing a
25% chance of 100 degree highs in the very hottest valleys in
Trinity County on Friday. Combined with dry air behind the trough,
such conditions will continue to dry fuels through the weekend.
Building high pressure will also support a usual cycle of nighttime
marine stratus with gusty north winds pushing on shore and helping
to mix out clouds each afternoon. Onshore winds will mostly likely
be strongest on Thursday with peak afternoon gusts around 30 mph.

Cluster ensemble members show another series of troughs digging
across the Pacific Northwest late in the weekend through early next
week. Though any impacts are sure to minor, the exact depth of the
troughs remains highly unlikely leading to two main possible
scenarios. 30% of models favor a weaker trough with high pressure
sneaking over the area. This would allow for another warm period
with interior temperatures back into the 90s. About 70% of  models
show stronger influence form the trough with NBM which would bring
cooler and more moist weather, especially to the coast. NBM is even
showing a 20% chance of wetting rain along the Del Norte Coast next
Monday. The very highest end models show light rain of up to 0.3
inches. A most likely scenario will come into better focus as models
continue to evolve. /JHW


&&

.AVIATION...A narrow band of stratus stretched over the North Coast from
Cape Mendocino to the Oregon border this morning; Over Humboldt,
Cigs were generally low MVFR...including ACV; but over Del Norte,
Cigs were mostly IFR...including CEC. Conditions became VFR before
noonday as a weak disturbance contributed to the scouring of clouds.
NW-N winds have increased today for somewhat gusty winds at ACV
and UKI.  Above ground winds will increase south of Trinidad
(Humboldt Coast) and along the Mendocino Coast through evening.
Although minimal, there is a chance for LLWS over ACV this
evening. MVFR/IFR clouds are expected to return to the Coastal TAF
sites overnight. The clouds are expected to mix out by late
Wednesday morning. /TA


&&

.MARINE...Moderate northerly flow will continue as the axis of an
upper trough traverses the PNW and far northern CA. While wind gusts
in the southern waters meet small craft criteria, wave heights will
hover around 5-7 feet under the influence of a decaying long period
NW swell. An offshore ridge building into the region will tighten
the inland thermal trough gradient and enhance offshore winds
Wednesday afternoon into Thursday. Gale conditions expected to build
on already enhanced conditions in the southern waters before
expanding north early Thursday. Rapid wind wave response expected
Thursday afternoon into Friday, with wave heights forecasted to
exceed 12 feet at 10 seconds by early Friday. Long range models are
beginning to agree on a progressive trough pattern developing this
weekend, effectively inhibiting the expansion fans downwind of Port
Orford and Cape Mendocino. Seas expected to follow suit as a
nearshore westerly swell traverses the waters.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 PM Wednesday to 9 PM PDT
     Thursday for PZZ450.

     Small Craft Advisory until 3 PM PDT Wednesday for PZZ455-
     475.

     Gale Watch from Wednesday afternoon through Thursday
     evening for PZZ455-475.

     Gale Watch from Wednesday evening through Thursday evening
     for PZZ470.

&&

$$

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