Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 222238
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
338 PM PDT Fri Mar 22 2024

.SYNOPSIS...Rain will continue to move southeast this evening with
a brief break in showers. Another line of showers will cross the
area early Saturday morning with a risk of isolated thunderstorms
especially along the coast. Drier weather will briefly return Sunday
into Monday.


&&

.DISCUSSION...A well defined cold front crossed the area early this
morning. This front brought about 0.5 inches of rain to many lower
elevation s location with up to 2 inches of rain in the most terrain
enhanced areas of the King Range. Wind gusts very briefly reached 45
to 50 mph at a few stations on exposed coastal ridges. Rain showers
have continued to spread east and south through the day with
wetting rain as far as Lake County.

Skies will briefly break this evening with blue skies already
evident along much of the North Coast. The break will be short
lived, however, with another line of showers and gusty winds
approaching shore late tonight through Saturday monring. This line
will produce very similar winds to this morning with very brief
gusts as high as 50 mph. That said, NBM has a less than 20% chance
of hourly gusts at the speed even on the highest ridges, indicating
any gusts of that speed will be short lived. The only exception to
this will be the rim of the Sacramento Valley as the front cross
east late Saturday morning. NBM is showing more sustained gusts int
hat are at high elevation, but no populated areas are expected to
see impacts.

Rain will become more showery along and behind this second front,
making rainfall both more inconsistent but less bound to elevations
the rain today. An additional 1 to 2 inches of rain is most likely
across most of the area except for drier conditions in far southern
Lake and Mendocino Counties. Cold air moving in aloft will help
increase instability through the morning Saturday, increasing the
chances (10 to 25% chance) of isolated thunderstorms along the
coast. Breaks of sun may even allow for some weak thunderstorms over
interior mountains. Cold air will also help drop snow levels,
currently around 5000 feet, as low as 3500 feet early Saturday
morning. This will bring more efficient snowfall to Scott Mountain
Summit with 3 to 8 inches most likely. Otherwise very wet and light
snow is possible (30 to 50% chance) on the highest passes of highway
36, but impactful accumulation is very unlikely.

Showers will gradually ease Sunday into Monday with clearing skies
bringing widespread valley fog and some isolated area of frost to
the near coast interior. Temperatures will stay cool int he 50s,
however, thanks to generally northerly flow. Calm conditions wont
last long, with good ensemble agreement on another, stronger system
mid week. Despite the distance, NBM is already putting a 50% chance
of gusts over 50 mph on ridges with this system. This suggest the
system will be both colder and stronger than the current system, with
an increased risk of wind and snow impacts as low as 2500 feet. Stay
tuned as the forecast evolves. /JHW


&&

.AVIATION...Plenty of unsettled weather changes occurred across the area, and
specifically impacted the TAF sites today. Conditions were due to a
low pressure system which was located west of the Oregon/California
border in the afternoon.  The most significant impacts today have
been LLWS ahead of a mid-morning front, along with gusty SSE-SSW
surface winds. Cig/Vis were mostly VFR with occasional MVFR in
moderate to heavy rain/showers. However, the main and more energetic
cold front moved across the North Coast by mid-afternoon and briefly
caused Cig/Vis to dip into IFR/MVFR in heavier showers and stronger
SSW winds. Except for Breezy-gusty southerlies, conditions will
basically improve along the coast before post frontal activity again
affect the region evening/tonight/morning; even isolated
thunderstorms are possible. Mid afternoon radar and Vis Satellite
showed tapering conditions this afternoon. However Mendocino and
Lake Counties were still getting "hammered".
/TA


&&

.MARINE...Unsettled weather will maintain an elevated sea state
through Saturday. Southerly winds will remain with isolated gale
force gusts in the northern waters. Short period waves will persist
as steep as 9 feet at 9 seconds. Southerly winds and seas will drop
Saturday afternoon and evening. Just in time for short period seas
to fall, a series of mid period swells will build throughout the
waters, peaking on Wednesday as steep as 14 feet at 11 seconds.
These conditions are hazardous to small craft and are borderline
hazardous seas criteria for all craft.

Calmer conditions are expected early next week with a stronger storm
system approaching the area by Wednesday. A steep swell up to 16
feet at 20 seconds will build by Wednesday night. The first waves of
this swell could arrive as early as Tuesday ahead of any elevated
wind, brining a moderate sneaker wave risk all along the coast
Tuesday evening. Besides the swell, even this far out NBM is
indicating at least 50% chance of gale force winds throughout the
waters Wednesday. /JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Weather Advisory from 11 PM this evening to 11 PM
     PDT Saturday for CAZ107.

     Winter Weather Advisory from 11 PM this evening to 11 AM
     PDT Saturday for CAZ108.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 6 PM PDT Saturday for PZZ450.

     Small Craft Advisory until midnight PDT Saturday night for
     PZZ455-470-475.

&&

$$

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