183
FXUS66 KEKA 011316 CCA
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
616 AM PDT Wed May 1 2024

.SYNOPSIS...Sunny skies and gusty northerly breezes are expected
today, especially for coastal areas of Mendocino and southwest
Humboldt. A front will generate light rain for Del Norte and
northern Humboldt Counties late tonight and Thursday. A much
wetter and colder system will bring a chance for heavy rain and
high mountain snow Friday night into Saturday.

&&

.DISCUSSION...Another chilly start this morning with multiple
interior stations in the lower to mid 30`s. In contrast, several
stations in southern Lake were in the lower 50`s. Frost advisory for
interior valleys of Humboldt, Del Norte and Trinity remains in
effect til 8 AM. A few sites have already fallen to 32F or lower
again.

Northerly breezes continued overnight for the exposed ridges.
Wind prone sites had peak gusts around 40 mph. So far NE winds
across higher elevations in Lake County have not been as strong,
gusting up to 32 mph. For coastal areas, gusty north winds are
forecast to diminish some today except for SW Humboldt and Mendocino
coasts where gusts 35 mph are likely (>60%) with daytime mixing.

A frontal system will approach from the NW this evening and disrupt
the surface pressure gradient north of Cape Mendocino. A shortwave
trough moving over the top of a broad flat ridge on Thursday will
generate an influx of moist air and light upslope precip. Highest
amounts are forecast to occur in Del Norte and west facing aspects
Del Norte and Northern Humboldt where HREF indicate 6 hourly
amounts up to 0.10in.

A colder upper trough with higher influx of moisture will bring a
threat of heavy rain rates Friday night. 6-hourly amounts may exceed
0.50-1.00 for Del Norte and northern Humboldt. 12-24 hour amounts of
1 to 3 inches are expected for interior Del Nort and Humbodlt. Even
southern Mendocino and southern Lake will get some rain, perhaps
0.50-1.25in over 12-24 hours on Saturday.

Much colder temperatures with mountain snow are forecast by early
Saturday morning above 4000 ft. Cold trough aloft will progress into
the Great Basin on Sunday. How fast this occurs remains uncertain
and showers may linger into Sunday. Additional shortwave troughs in
brisk NW flow aloft may generate more showers early next week.
Stronger ridging from the SW may bring warming and drying instead.
Clusters are about evenly split on this. Either way it does not look
like a persistently wet pattern. DB

&&

.AVIATION...Mostly VFR conditions have persisted at the terminals
tonight, with some brief drops to MVFR at ACV. Temporary drops to
MVFR could continue this morning until solar radiation lifts any
lingering clouds. VFR conditions will prevail today. Northerlies
will continue to be gusty in the afternoon at all the terminals and
diminishing by sunset. An approaching front will bring low clouds
and rain to the coastal terminals tonight, diminishing conditions
down to IFR or MVFR. UKI looks on track to stay mostly clear for the
next 24 hours, but a low level wind shear threat is possible
tomorrow night. JB

&&

.MARINE...Gusty northerly winds tonight will continue through most
the day. Gusts will be near or at gale force in the southern waters,
particularly south of Cape Mendocino. Winds and waves will begin to
diminish in the late afternoon in the northern waters. The southern
waters will remain gusty through early Thursday morning. Aside from
northerly breezes south of Cape Mendocino, winds and seas will
subside Thursday. On Friday afternoon winds will shift increase and
shift westerly as a front approaches, before turning northerly and
increasing further Saturday. JB

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Frost Advisory until 8 AM PDT this morning for CAZ102-
     105>108.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT Thursday for PZZ450-470.

     Gale Warning until 8 PM PDT this evening for PZZ455-475.

&&

$$

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