599
FXUS66 KEKA 221316
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
516 AM PST Wed Jan 22 2025

.SYNOPSIS...Mostly dry for the next seven days with the exception
of potential light rain or snow late Friday night into Saturday
morning for parts of central and southern Lake County. Chilly nights
and mornings, especially this morning and Wednesday morning, and
again for this weekend. Potential for gusty winds return to the area
Friday through Sunday, focusing on the coast Friday, and then
including interior locations Saturday into Sunday.

&&

.DISCUSSION...

Key Messages:

Cold mornings are forecast through early next week, especially this
morning, and over the weekend. There is strong potential for gusty
winds for parts of the area Friday through Sunday. There is a small
potential (20% chance) of some light snowfall for higher elevations
of central and southern Lake County late Friday night into Saturday
morning.

Weather Pattern Overview:

Upper level ridge over the eastern Pacific will give way on the
eastern periphery to a sizable upper trough sliding in from the east.
This trough has been consistently forecast with the trough axis
remaining south and southeast of our area. Model trends have
continued to backed off of rain chances for the Friday through
Sunday time range. However, Lake County will be close enough to the
trough axis to stand the best chance of some light precipitation,
with potential for some light snow.

Forecast Confidence and Deviations:

Wind gusts will increase to over 30 mph along the coast on Friday,
and increase to over 30 mph over parts of the interior for Saturday,
especially on ridges. Lows are forecast to be mostly in the 30s
through the weekend, and wind chills or "feels like" temperatures
possibly near or a bit below freezing on some days, especially this
weekend. Interior valleys on Sunday morning are forecast to dip to
near 20 degrees for some areas.

Ensemble trends are indicating a generally decreased chance of
precipitation from Friday into Saturday. Chances of receiving 0.05
inches or more of precipitation have decreased to less than 20%
during the Friday through Sunday night time period for all but Lake
County, with the most likely time window for precipitation there
being late Friday night through Saturday morning.

On Friday, we stand a roughly 20-40% chance of hitting gusts greater
than 45 mph along the coast. On Saturday as chances increase for
strong wind gusts in the interior, there is a 60% chance of wind
gusts greater than 45 mph on Saturday for Clearlake in Lake County,
but still near 50% up in Crescent City, with the rest of the coast
decreasing to much lower chances. NBM indicates peak gusts will top
out Friday afternoon and evening, but interior areas stand to get
their higher gusts in the all day Saturday through early Sunday
morning time frame.

Mean Wet Bulb Globe Temperatures from the NBM indicate that Sunday
morning will be the feel the coldest over the next seven days,
reaching upper 20s along the coast to near 20 or slightly below for
portions of the interior.

The deterministic forecast highs for today Thursday will be near or
well below the 25th percentile, leaning more toward the
deterministic NBM, which trains on more recent trends. Lows for the
next couple nights follow the same pattern, but closer to 25th
percentile and not much below. /MH


&&

.AVIATION...Skies are mostly clear across the area this morning,
although offshore flow is generally a bit weaker. A few of the
valleys in Humboldt county may have some patchy fog. Air is very dry
this morning just off the surface and the east winds are bringing
this to the coast. So at this point it looks unlikely that any
significant fog will form at TAF sites this morning. VFR conditions
and light winds are expected through the day. Tonight offshore flow
is expected to continue keeping skies mainly clear overnight. It
looks a little stronger than this morning. MKK

&&

.MARINE...The northerly winds this morning have started to increase
and models are in decent agreement that winds will peak around 15 to
20 kt by the afternoon. The strongest winds are expected to be in
the afternoon just downwind of Cape Mendocino reaching just over 20
kt. It looks like the coverage of over 21 kt will be too small to
warrant a small craft advisory, but will continue to monitor this.
Late tonight and Thursday these winds diminish to around 5 to 15 kt
with the strongest winds well offshore. Another long period wave is
expected to move through on Thursday, although the current models
show it around 3 feet at 16 seconds Thursday evening building to

A more significant wind event is expected Friday and Saturday.
Northerly winds are expected to start increasing Thursday night with
additional increases through Friday. Gale force gusts are likely by
sunrise Friday morning around 50 to 60 NM off Pt St George. These
are expected to quickly spread closer to the coast and farther south
through the morning and into the afternoon. At this point it looks
like there may be a few gale force gusts in the inner waters Friday
afternoon through Saturday morning, however the hi-resolution models
may show stronger winds in the inner waters once they go out far
enough. The models are coming into better agreement that these winds
will diminish Sunday afternoon and evening. Have issued a gale watch
for the outer waters where there is higher confidence of gales for
Friday through Saturday evening.

Sunday winds are expected to remain in the 15 to 25 kt range and
slowly diminish through the day with lighter winds expected next
week. A small swell of 4 to 5 feet at 15 seconds is expected to
linger as well. MKK

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Cold Weather Advisory until 9 AM PST this morning for
     CAZ113-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Gale Watch from Friday morning through Saturday evening for
     PZZ470.

     Gale Watch from Friday afternoon through Saturday evening
     for PZZ475.

&&

$$

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