Flood Watch 5, NWS Eureka, CA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
535 AM PDT Fri Mar 14 2025

.SYNOPSIS...Strong and gusty southerly winds will continue to
develop as the front passes through this morning. An atmospheric
river will bring a chance for heavy rain as well as strong and
damaging winds this weekend.

&&

.DISCUSSION...A fast moving front just offshore as of 11z this
morning has already produced gusty winds, rain and snow at higher
elevations. The previous run of 925mb model winds definitely
verified as buoys offshore are already reporting 40-42kts of gusts.
Higher wind gusts are forecasted for the coast as the front
approaches, HREF indicates a 60% chance of gusts 50 mph or more. The
NBM is much lower with highest chance for gusts over 40 mph tied to
the higher terrain surrounding Humboldt Bay and Eel delta, generally
above 1000-1500 feet. Instability is not as prevalent this morning
but this could change as daytime hours change the dynamics with
elevated convection accompanying the occlusion.

Some snow has already been reported at Dunsmuir, Grants Pass, and
Klamath Regional Airport, north of our CWA. It seems like this
system is a bit warmer than anticipated yet low elevation snow is
still possible. Observations and reports of snow at Cobb 3223 ft
and between Hopland and Lakeport at 2500 ft. Across Trinity
County, low snow levels below 2000-2500 ft should sustain through
much of the day for heftier accumulations for populations centers
and 299 corridor. A winter storm warning has been posted for
Trinity County for elevations above 1500 feet, though levels may
increase to 2000-2500 feet during the heating of the day.
Elsewhere, for Humboldt, Del Norte, Mendocino and Lake, snow
amounts will be minimal for an advisory, 1 to 2 inches with local
accumulations near 4". Impacts may be greater due to heavier motor
vehicle traffic on hwys 101 and 20. Erred on the side of caution
and a winter weather advisory is in effect this morning. Snow
levels should gradually rise over the weekend with less impacts
for most of the major passes. The exception will be Scott Mtn pass
and perhaps south Fork Mountain.

We may get a break in the active and wet weather on Saturday as a
ridge pumps up over the area. More specifically, Del Norte and
northern Humboldt will probably continue to have periods of light to
moderate rain. Mendocino and Lake will have lower probabilities for
precip. An atmospheric river storm (AR1/AR2) will most likely bring
another bout of moderate to heavy rain and possibly hefty high
mountain snow toward the end of the weekend into early next week. We
posted a graphic on social media platforms and our web page to
highlight this event. Snow levels should rise up over the weekend,
however travel impacts above 4500-5000 feet are possible.
There is still a great deal of variability and spread with the
timing and magnitude of winds with this next storm. ECMWF ensemble
EFI has been flagging anomalously strong winds for mid March,
Saturday night into Sunday, for multiple iterations now. Looking at
the ensemble meteogram of 6 hourly max gusts, ensemble means are
over 50 mph for Crescent City area with multiple members of 58-67
mph gusts. Probabilities are less than 50%. Stay tuned for updates.
Another break in the wet and active weather is forecast for Tuesday
as a transient ridge builds. Landfall AR tool from CW3E Hovmoller
diagram indicates increasing probabilities for IVT over 250kg/m/s
mid to to late week. Periodic wet weather will probably continue mid
to late week with no signs for long duration drying for multiple
days.

&&

.AVIATION...A cold front is currently just offshore and bringing
gusty winds and some low level wind shear to the coastal terminals.
Some of the gusts are expected to make it farther inland. This front
is expected to bring some lower CIGS and VIS in the morning, likely
MVFR conditions with locally IFR conditions. Also, a fairly sharp
wind shift is expected right with the front in the morning. Once the
front moves through showers are expected to pick up and some of
these may be strong enough to have lightning in them. At this point
confidence isn't high enough to add them to the CEC or ACV taf, but
the potential is still there. This afternoon west to northwest wind
gusts are expected to increase again with gusts to around 20 to 25
mph. The winds are expected to diminish overnight again. MKK

&&

.MARINE...Strong Gales, with isolated storm strength gusts in
portions of the northern waters are present early this morning as
the dynamic frontal system moves through NW California. A gale
strength southerly low-level jet is forecasted to linger longer
along the Northern Inner zone 450 into late Friday morning. Steep
winds waves are present due to these strong winds as well.

Winds will ease to breezy conditions behind the front, turning
westerly at around 25 kts through the afternoon. This westerly flow
will have a relatively broad and vigorous fetch, and will usher in
large and very steep westerly waves. These waves are currently
forecast to reach Hazardous Seas criteria in at least portions of
the waters late this afternoon, with very seas up to 19 ft.
Hazardous Seas Warnings have been issued in all zones to cover this
developing forecast. These seas will slowly subside through Saturday
as the southerly winds begin cranking up once again.

Gale to Strong Gale strength southerlies are again forecast to
develop Saturday afternoon through Sunday due to an incoming front
setting up around the Oregon/California boarder. Winds are currently
expected to be strongest in the northern waters and remain for
multiple hours.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Wind Advisory until 11 AM PDT this morning for CAZ101-103-
     104-106.

     High Wind Watch from Saturday afternoon through Sunday
     afternoon for CAZ101.

     Winter Weather Advisory until 11 AM PDT this morning for
     CAZ102-105-110-111-114-115.

     Winter Storm Warning until 5 PM PDT this afternoon for
     CAZ107-108.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Gale Warning until 11 AM PDT this morning for PZZ450.

     Hazardous Seas Warning from 5 PM this afternoon to 3 AM PDT
     Saturday for PZZ450-455-475.

     Gale Warning until 9 AM PDT this morning for PZZ455-470-475.

     Hazardous Seas Warning from 9 AM this morning to 3 AM PDT
     Saturday for PZZ470.

&&

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

Preliminary Local Storm Report
National Weather Service Eureka CA
633 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0623 AM     Non-Tstm Wnd Dmg 4 ESE Willits           39.37N 123.28W
03/14/2025                   Mendocino          CA   Dept of Highways

            TREES and PWOER LINES DOWN.

&&

DS

Preliminary Local Storm Report
National Weather Service Eureka CA
635 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0551 AM     Non-Tstm Wnd Dmg 2 SW Orick              41.26N 124.09W
03/14/2025                   Humboldt           CA   Public

            TREE DOWN BLOCKING NB LANE. 12IN DIAMETER.

&&

DS

Preliminary Local Storm Report
National Weather Service Eureka CA
735 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0650 AM     Non-Tstm Wnd Dmg 1 SSE Humboldt Hill     40.71N 124.18W
03/14/2025                   Humboldt           CA   Law Enforcement

            Trees and brush blocking road.

&&

Preliminary Local Storm Report
National Weather Service Eureka CA
737 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0644 AM     Flood            1 SE Humboldt Hill      40.72N 124.18W
03/14/2025                   Humboldt           CA   Law Enforcement

            Roadway flooding.

&&

Preliminary Local Storm Report
National Weather Service Eureka CA
818 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0730 AM     Non-Tstm Wnd Dmg 4 ENE Pepperwood        40.48N 123.92W
03/14/2025                   Humboldt           CA   Law Enforcement

            MULTIPLE TREES ARE DOWN.

&&

TJ

Preliminary Local Storm Report
National Weather Service Eureka CA
1031 AM PDT Fri Mar 14 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1023 AM     Non-Tstm Wnd Dmg 2 ENE Myrtletown        40.81N 124.09W
03/14/2025                   Humboldt           CA   Law Enforcement

            Downed power lines across road.

&&

TJ