568
FXUS66 KEKA 061302
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
602 AM PDT Thu Jun 6 2024

.SYNOPSIS...Interior heat will peak today with isolated areas of
major heat risk expanding into the eastern Trinity River Valley in
addition to Lake County. There remain a very slight chance of
isolated thunderstorms over high terrain this afternoon. Conditions
will ease into the weekend.


&&

.DISCUSSION...Surface high pressure and associated heat will peak
across interior valleys today. Most of Lake COunty especially is
already starting out warm with overnight lows in the mid 60s. NBM
continues to put a 70 to 90% chance of highs over 100 today in
southern Mendocino and Lake Counties and even up into the Trinity
River Valley. Moderate to locally major heat risk is highlighted
across interior Valleys but especially in Lake County and along the
eastern Trinity River.

Beyond temperature, strong solar heating will also help increase
surface instability. At the very least, this will most likely
generate more impressive and visible afternoon cumulus clouds over
high terrain. Model soundings have eased off of instability a a bit
still show up to 1000 J/Kg of CAPE late this afternoon over high
terrain. Despite this fact, total column moisture is marginal at
best and any lifting would have to break through a midlevel cap and
reach near 15 kft for thunderstorm formation. These factors make the
formation of isolated afternoon thunderstorms possible though
unlikely (10 to 15% chance) late this afternoon and evening.

Closer to the coast, high pressure will continue to promote a thin
but persistent marine layer with temperatures solidly in the 60s and
stubborn coastal fog and stratus. Compared to yesterday, however,
Strong heating, however, any marine clouds have been particularly
patchy and ragged, likely promoting quick clearing today.

High pressure will weaken into the weekend with a narrow trough
crossing the area around Sunday. Such a pattern will push marine
influence further inland and bring interior temperatures back into
the low to mid 80s. With little moisture to speak of, however,
essentially no ensemble members show rain with the trough beyond
coastal drizzle. That said, increased midlevel moisture with a bit
of upper level support and June sun could promote isolated afternoon
thunderstorms. Probabilities remain low (less than 20%) but chance
should be watched closely, especially Saturday. Essentially all
cluster ensemble members show a ridge of high pressure centering
over the Pacific Northwest early next with low pressure stalled off
the California Coast. Such a pattern will bring typical to slightly
above average summer temperatures. Only about 15% of ensemble
members currently show any temperatures hotter than the current heat
wave. /JHW


&&

.AVIATION...Stratus has been limited in development during the early
morning hours. KCEC will have IFR flight categories through the
morning with occasional bouts of MVFR as visibility degrades with
calm winds aiding in mist or fog development and obscuration.
Ceilings will hover around 1000 feet before lifting out this
afternoon as model soundings do show tempertures inversion yet a dry
profile throughout. Expect stout northerly winds at KCEC with gusts
form 20 to 24 kts this afternoon as pressure gradients steepen from
a strengthening upper level low off the Canadian coast. Low level
wind shear does not look to be an issue at this time as the wind
profile is fairly consistent in direction and uniform with respect
to height. KACV has a closer temperature and dewpoint profile with
model soundings from MOS guidance which may only result in minor
obscuration as HREF indicates MVFR categories this afternoon. A
return to LIFR/IFR conditions early Friday morning is likely with
light winds. VFR conditions will prevail at KUKI with light
southerly winds overnight into Friday. The afternoon northerly gusts
are not being signaled by guidance today. /EYS


&&

.MARINE...The northwesterly swell is diminishing yet conditions at
sea remain hazardous for small crafts as mid period swell and
locally generated wind waves persist. Gale conditions for the
northern outer waters will begin in the late afternoon around 22z
and could last through to Friday morning around dawn. The Gale
conditions in the southern waters will reduce in coverage yet remain
elevated south of Cape Mendocino. Steep northerly waves persist in
the southern outer and inner waters with northerly groups 10 to 11
feet, with as many seconds in period. NW swell around 6 to 8 ft at
12 to 13 seconds linger as well. All zones are expected to subside
to sub-10 foot wave heights by late this week and early weekend as
the swell subsides. /JMM /EYS


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement until 9 AM PDT this morning for
     CAZ101-103-104-109.

     Heat Advisory until 8 PM PDT this evening for CAZ114-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT this evening for PZZ450.

     Gale Warning until 9 AM PDT this morning for PZZ455-475.

     Hazardous Seas Warning until 3 PM PDT this afternoon for
     PZZ470.

     Gale Warning from 3 PM this afternoon to 3 AM PDT Friday
     for PZZ470.

&&

$$

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