192
FXUS66 KEKA 112215
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
315 PM PDT Thu Jul 11 2024

.SYNOPSIS...Very hot and dry weather will continue in the interior
through Saturday. Interior heat is forecast to moderate Sunday and
early next week. Coastal areas will remain cool with occasional fog
and low clouds through the weekend.


&&

.DISCUSSION...Interior heat will continue to build through
tomorrow with an excessive heat warning remaining in effect for
triple digit temperatures in the interior valleys. Ukiah Municipal
Airport should tie or set a new record today and tomorrow.
Records are 110F for today set in 1913 and 107F for Friday set in
1927.

In general, max temperatures are forecast to diminish a few
degrees by Saturday, but with triple digit heat persisting and
elevated heat risk in the interior, the excessive heat warning has
been extended. However, a few locations are forecast to be hotter
on Saturday. The heat risk is forecast to abate by Sunday and
into early next week as a trough approaches from the NW. It will
still be quite hot in the interior on Sunday; 96-103F. High
temperatures, according to NBM, are forecast to remain near or
above normal early next week; 94-103F. So the relief from the heat
is not going to be all that dramatic, though the heat risk is
forecast to become moderate.

By far the greatest concern heading into the weekend will be the
potential for dry lightning. Mid level humidity and perhaps some
alto-cumulus will spread northward over NW California during the
weekend as a semi-closed upper low pin-wheels off the central
California coast. The cut-off will eventually lift out to the NE.
How fast that occurs is not 100% certain. The latest deterministic
models indicate Sunday as the day with the highest chance. NBM
indicates no more than a 10% chance both Saturday and Sunday.
Greater uncertainty arises with the location and timing of dry
storms. More on this in the Fire Weather section.

Coastal areas will remain cool. Stratus is expected to reform over
the North Coast this evening and overnight. Nearshore southerly wind
reversal will probably redevelop and even the Mendocino Coast will
not be stratus and fog free. Status and fog will most likely
continue to be the norm for coastal areas through the weekend and
early next week.


&&

.AVIATION...Another stratus-ladened North Coast this morning...engulfing the
Humboldt and Del Norte shorelines; very little along Mendocino.
Although the stratus was solid, several (rare) pilot reports
(pireps) announced low LIFR/IFR bases and MVFR tops 1000-1500 feet.
There were some Vis impacts due LIFR/IFR conditions also...
especially at CEC. Shortly before/after noonday, several breaks in
the overcast (binovc) opened up around Humboldt Bay-ACV and
introduced scattered conditions at ACV. The marine layer will start
"filling-in" along the coast by late evening and bring conditions
down to LIFR/IFR overnight according to most model guidances...and
recent marine stratus behavior.  VFR conditions will continue to
prevail across inland areas. /TAA


&&

.MARINE...Gale force northerlies in the outer waters will continue to
increase today. Winds will peak this evening with gusts up to 45 kts
in the outer waters. Nearshore waters will largely be shielded from
the strong winds, seeing breezes of 15 to 20 kts. Hazardous seas
will accompany the gale force winds in the outer waters, with
significant wave heights to 15 ft. The inner waters will see steep
wind waves around 9-12 ft at 9 s. Conditions begin to improve this
weekend as gales diminish by Saturday and wave heights drop below 10
ft by Sunday. Northerlies will remain elevated in the outer waters
through the weekend and will most likely drop below gale force into
early next week.


&&

.FIRE WEATHER...A building pressure gradient along shore will aid
in gusty north winds each afternoon for near coastal areas. In
addition such a pattern will enhance diurnal wind, especially
along the rim of the Sacramento Valley. This may promote isolated
critical conditions in southern Lake County into the weekend.

Models continue to suggest a plume of monsoonal moisture this
weekend. Elevated convection could develop as far south as Lake
County by Saturday evening and as far north as northern Trinity
County by Sunday, but not necessarily in between these two areas.
Highest probability according to NBM is 8% over NE Trinity.
Specific timing, location, and even possibility of occurring
remains uncertain for the NW California forecast area. A headline
remains in place in the fire weather forecast. Stay tuned for
updates.




&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Heat Advisory until 9 PM PDT Saturday for CAZ104-106-112.

     Excessive Heat Warning until 9 PM PDT Saturday for CAZ105-
     107-108-110-111-113>115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT Saturday for PZZ450.

     Small Craft Advisory until 3 AM PDT Friday for PZZ455.

     Gale Warning until 9 AM PDT Saturday for PZZ470-475.

&&

$$

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