099
FXUS66 KEKA 041112
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
412 AM PDT Sat May 4 2024

.SYNOPSIS...A passing cold front will continue to bring periods of
heavy rain early this morning, with snow above 2500 feet. A much
colder airmass will then settle in behind the front to bring near
freezing to freezing temperatures for some interior valleys.


&&

.DISCUSSION...A late season cold front brought widespread heavy
rainfall rates up to 0.5 inches per hour overnight and this morning.
Interior snowfall continues as snow levels are quickly dropping. The
Winter Weather Advisory remains for elevations above 2500 feet. A
seasonably anomalous, cold upper low will work its way over N CA
throughout the day. Associated instability and 700mb temperatures
as cold as -13C will bring showers and possibly a thunderstorm, some
which could contain small hail through this evening. Colder to much
colder than average tempertures will remain in place through the
weekend and into next week. Near freezing to freezing temperatures
for some interior valleys are forecast, but expected fog will
hold the temperature up for some valleys over the next couple of
nights. A pronounced ridge of high pressure will then begin
building in mid to late next week, and there is growing
probability for the warmest interior valleys to exceed 85 degrees
through that period. /JJW


&&

.AVIATION...Biggest problem to deal with to start the forecast will be
ceilings in the IFR to MVFR range behind a cold front as wind has
shifted to the west. Cold front aloft will play a part in some
thunderstorm potential this afternoon and evening, although chances
are quite small. Ensembles indicate the chance of MVFR or worse
ceilings dips below 50% along the coast by about 21-22Z, and toward
17Z for KUKI. For visibility, the overall trend is for improvement
in visibility for all TAF sites, except for some potential that some
slight worsening of visibility will occur within the first couple of
hours of the forecast. Can`t rule out the potential for small hail
accumulation for the coast this afternoon and early evening. We may
not completely lose our light rain or drizzle potential through the
night tonight and into early Sunday morning.


&&

.MARINE...After strong winds occurred directly behind a passing cold
front earlier this morning, gusty northwest winds will become
confined to the southern waters by late this morning, with the
potential for thunderstorm development. Steep wind wave response
expected late today through Sunday as lingering showers dissipate.
Combined seas today are forecast to be 5-7 feet with 7-9 second
periods through the weekend before a long period northwest swell
fills in early next week. Strong northerlies combined with another
steep northwest swell by Tuesday night or Wednesday may produce
combined seas exceeding 10 feet.

A few persistent northwest swells for the next several days will
play a factor in combined wave height increasing by mid-week. Small
craft advisories are all ending by mid-evening tonight.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Weather Advisory until 11 AM PDT this morning for
     CAZ102-105>108-111.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT this morning for PZZ470.

     Small Craft Advisory until 9 PM PDT this evening for PZZ475.

&&

$$

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