004
FXUS66 KEKA 060028
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
428 PM PST Wed Feb 5 2025

.SYNOPSIS...An upper level trough continues into the region, cold
and wintry weather patterns are expected. Rivers continue to
recede as precipitation diminishes, allowing major stem rivers to
exit flood stage. The weekend may see light showers with dry and
chilly weather expected early next week.


&&

.DISCUSSION...A cold upper level trough continues to slide down
the Pacific Northwest Coast. This will bring chillier tempertures
to Northwest California. Snow is expected mostly above 2500 feet
elevation Thursday and Friday for Trinity County, along with
interior Humboldt and Del Norte counties and the highest
elevations of northeastern Mendocino and extreme northern Lake
counties. At the same time, a surface low pressure system is
forecast to make landfall around the Humboldt Coast by tomorrow
afternoon. The surface low will bring gusty winds for Thursday and
Friday. Also, an influx of tropical moisture will bring more rain
for the region. This push of tropical moisture will keep Mendocino
and Lake counties slightly warmer with snow levels climbing to
5000 or 6000 ft Thursday and Friday.

Showery conditions will continue for the region into this evening
before another push of precipitation begins by early Thursday
morning. Total 48 hour precipitation totals could be anywhere from
0.5 inches to 2.5 inches, with the higher totals on the windward
side of the mountains and the highest ridges and lower amounts in
the rain shadowed interior valleys along with the coastal plains
around Humboldt Bay and coastal Del Norte.

Gusty winds are expected, especially for Lake and Mendocino
counties along with the higher terrain areas of southern Humboldt
and Trinity counties. Gusts on Thursday afternoon could be
anywhere from 25 to 35 mph. NBM indicate a 55 to 65 percent chance
of gusts over 35 mph in the highest terrain areas along the
Mendocino and Lake county border.

Snow levels for Humboldt, Trinity and Del Norte will be mostly
above 2500 feet. A Winter Storm Warning has been issued for
Northeastern Trinity County Thursday afternoon through late Friday
morning which has a 75 to 80 percent chance of total snow
accumulations of 8 inches over a 24 hour period. This will have
impacts along the northern portions of HWY 3. Also, Winter Weather
Advisories have been issued for interior Del Norte, northern
interior Humboldt and Southern Trinity counties. This will have
impacts on HWY 199 near the Oregon border, portions of HWY 299
near Berry Summit, along with HWY 36 through Trinity county.

By early this weekend, the upper level trough remains near the
area. This will keep temperatures chilly, especially the overnight
lows. Some very light precip is possible, but at this point it is
less likely. Sunday and Monday cool and dry conditions are
expected. /JLW


&&

.AVIATION...Today, NW California`s Taf sites (CEC, ACV and UKI) remained under
the influence of a front that was in frontolysis mode by early
afternoon. However, accompanying the front was enough energy that
became the catalyst for showers to continue...and for a few
thunderstorms to pop up...especially near Cape Mendocino and CEC
airport. Cig/Vis have generally remained VFR/MVFR except during
periods of heavier precipitation. Another wave of convection began
to develop over coastal waters in the mid-afternoon. Surface winds
have been gusty along the Coast. Above the ground winds (2000
feet/boundary level) increased this morning for the possibility of
LLWS. UKI was LIFR/IFR in the morning due to fog and low Cigs, but
reached VFR briefly around 18z before descending into MVFR in rain.

Next 24 hours (through Thursday), model guidance is indicating a
brief weather reprieve late tonight before influence from an
offshore low brings additional adverse conditions to the coastal
airports after midday. UKI can expect further low conditions to
disrupt aviation operations in the morning. /TA


&&

.MARINE...Gusty southwesterly winds are being observed this afternoon
as a cold upper trough and surface low cycles off the PNW coast.
Small craft conditions will continue in the northern waters with 20
to 25 knot gusts and 7 to 9 foot seas. Scattered convection embedded
within lingering rain showers will diminish this evening as the low
gradually weakens. Several small to moderate swells will make for a
conflicting sea state for the remainder of the week as winds turn
northerly again by Friday.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Weather Advisory until 6 PM PST this evening for
     CAZ101.

     Winter Storm Warning until 10 PM PST this evening for
     CAZ102.

     Winter Weather Advisory from 4 PM Thursday to 10 AM PST
     Friday for CAZ102-105.

     Winter Weather Advisory until 7 PM PST this evening for
     CAZ105>108.

     Winter Storm Warning from 10 AM Thursday to 10 AM PST
     Friday for CAZ107.

     Winter Weather Advisory from 10 AM Thursday to 10 AM PST
     Friday for CAZ108.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 8 PM PST this evening for PZZ450-
     470.

&&

$$

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