Area Forecast Discussion
Issued by NWS Eureka, CA

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526
FXUS66 KEKA 261123
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
423 AM PDT Sun May 26 2024

.SYNOPSIS...Mostly clear skies and dry conditions are expected
today once some morning low clouds in Humboldt county lift. Highs
are expected to be around 80 in the interior today warming into
the low 80s Monday. Cooler temperatures and coastal fog and
drizzle are expected Tuesday. A warming trend is expected Thursday
through Saturday.

&&

.DISCUSSION...Weak high pressure is over the area bringing mainly
clear skies and dry conditions to the area. Warmer temperatures
are expected this afternoon. Coastal and valley clouds and fog are
limited to mainly Humboldt county this morning morning thanks to
a weak inversion and offshore flow. Breezy conditions are expected
along the coast once again this afternoon with northwest winds of
10 to 15 mph. Most areas are expected to see clearing today, but
it may take some time for the stratus to clear at the coast.

Monday there is an upper level trough moving into the Pacific
Northwest and this will be felt in Northwest California. Monday
afternoon there is a small chance for showers and possible a
thunderstorm in northern Trinity county. There is some
instability, but with the poor lapse rates in the mid levels it
looks like there might not be any thunder. Also, only the SREF
thunder probabilities are showing more than 5 percent. So for now
have just added a slight chance of showers for northeastern
Trinity county. This approaching trough is expected to shift the
wind field to more onshore and stratus is expected to return on
Monday. Monday night and Tuesday this is expected to continue to
deepen the marine layer and drizzle is likely along the coast.
Tuesday is expected to see cooler temperatures with highs dropping
back into the 70s. The coast may stay in the 50s with the
expected marine layer lingering through at least midday. Wednesday
the trough starts to pull out of the area but coastal clouds may
be slow to clear out and the interior will continue to see highs
in the 70s. This is a couple degrees below normal.

Thursday through Saturday night pressure starts to build into the
area and inland areas will see warmer temperatures. The mid 80s
are expected Thursday. Friday looks to be the warmest day with
highs in the upper 80s to around 90. The NBM shows a 50 to 75
percent chance of high temperatures exceeding 90 degrees in the
valleys. The ensemble clusters still show uncertainty on this
warmup. Friday a couple of the clusters show the trough lingering
over the Great Basin longer and keeping temperatures cooler.
Saturday the models are in better agreement in the start of a
cooling trend as another trough moves towards the area. MKK

&&

.AVIATION...12Z TAF
ACV/CEC...Stratus formed along the coast after midnight and began
expanding into ACV and up the coast toward CEC in a southerly
component of a coastal wind eddy. Light offshore surface winds are
keeping full inundation to the coast so far. Model soundings lower
CIGs through sunrise to LIFR levels as the stratus fills in, and
patchy fog may develop. With a building ridge and increasing 850 mb
temperatures, the McKinleyville profiler is beginning to show the
signature of a strengthening low level inversion. This may hinder
but not fully inhibit typical scattering of the stratus,
particularly around Humboldt Bay. Surface moisture and moisture
pooling will increase tonight as subtle influence from an
approaching late season Pacific trough takes effect. This will
increase chances for LIFR CIGs and VIS towards the end of this 12Z
TAF period, as well as potential good coverage of early morning fog
at the coastal terminals.

UKI....With a shallower marine layer, the threat for spillover from
the west is gone. Winds will also be light and mostly variable. A
few W to WNW afternoon gusts may occur. VFR conditions are expected
to prevail with no clear signature for southerly flow and stratus
transport.

&&

.MARINE...A weak northerly wind pattern persists. Winds continue to
be accelerated south of Cape Mendocino where gusts up to 32 kts and
short period seas of 6 to 8 feet create Small Craft Advisory
conditions. The steepened seas in the northern waters will drop to 5
ft or less today as winds drop to 15 kt or less. Expect very similar
conditions to carry into next week. Coverage of Advisory winds in
the southern zones will become more narrowly confined south of the
cape, but coverage justified extension of the Advisory. A mid period
NW swell at around 5 ft at 13 seconds from a late season Pacific
trough of low pressure will also arrive on Tuesday. Building high
pressure mid to late next week will increase northerly winds in all
zones. There is growing probability for gale conditions through that
period.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT this morning for PZZ455-
     470.

     Small Craft Advisory until 11 PM PDT this evening for
     PZZ475.

&&

$$

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