Small Craft Advisory 31, NWS Eureka, CA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
406 AM PST Tue Mar 5 2024

.SYNOPSIS...Rain will peak late this morning with snow levels
continuing to rise. Calm, clear conditions are expected mid to late
week with gusty north winds near shore. Light rain will most likely
return late this weekend.

&&

.DISCUSSION...A meandering cutoff low is evident off the central
California coast early this morning. Southerly wind rotating around
the low has helped pull generally warmer and more moist are across
the area. In contrast to this weekends snow, temperature near the
coast have returned to near 50 with snow levels in excess of 4500
feet. Trinity county is the exception tot his trend where high
stability associated with advected arm air has allowed for cold air
from the past weekend to remain trapped in valleys. This pattern is
evident in low temperatures below freezing across Trinity County
early this morning. In these valleys, snow levels may be as low as
2500 feet.

A weak to moderate stream of moisture has pulled around the low,
generating light stratiform rain all along the coast overnight. Most
of the area, even as far as Lake County, has seen 0.5 to 1.0 inches
of light rain over the past 24 hours. Rain rates will peak later
today as cold front extending from the low sweeps down the coast
from the north to south. The HREF indicates peak precipitation rates
of 0.3 to 0.5" per hour are most likely early this morning on the
North Coast, aided by the initial slow movement of the front across
Del Norte and Northern Humboldt Counties. At higher terrain, most
likely rainfall will be 1 to 2.5 inches across the the northern half
of the area with 0.5 to 1.0 inches at lower elevations. Though not
particularly strong, such rain rates could generate minor urban and
small stream flooding concerns on the immediate North Coast. In
terms of rivers, only the Mad River at Arcata is expected to reach
monitor stage with less than 10% chance of flood stage. Generally
speaking, the southwest wind direction along the front and
associated terrain effects will not be favorable for any flooding
concerns. Snow levels will remain above 4000 feet except where cold
air is dammed in Trinity County. Cold valleys could see light (less
than 1 inch) snow this morning with 3 to 6 inches on the very
highest mountain passes (Scott Mountain) through the afternoon.

As the low continues to dip south along the California coast.
northerly wind will settle in, advecting cooler and drier air across
the area except along the immediate coast where gusty onshore flow
(up to 30 mph) could promote shallow marine influence. For most of
the interior, this will spell calm, cold, and clear conditions. NBM
shows this well with night time lows near or below freezing each
night by Thursday morning. Despite cold overnight temperatures,
clear skies and increasingly strong sun will help interior valleys
reach into the upper 50s during the day. At least briefly building
offshore flow could even bring calm and cold overnight conditions to
the coast Friday morning with lows near freezing.

Model ensembles generally show a series of weak shortwaves bringing
periods of light rain across the area through the weekend.
Essentially no members indicated impactful rainfall until at least
mid next week when 30% of ensemble members show a moderate
atmospheric river impacting northern California. /JHW

&&

.AVIATION...A quasi-stationary front has set up around the CA/OR
border overnight, bringing light rain just north of KCEC along with
IFR ceilings and gusty south winds across Del Norte, with ceilings
increasing to MVFR for areas further south. This front is forecast
to sweep southward down the coast through the day today, which will
bring a period of lower ceilings and light to moderate rainfall
across Humboldt by midday and eventually Mendocino by late tonight.
Light northerly winds fill in behind this feature, although a weak
southerly reversal may set up late tonight between Trinidad and
Crescent City...possibly bringing periods of LIFR ceilings to KCEC
late tonight, although confidence is low as to whether or not this
will occur. Interior valley fog is expected for the northern half
of the CWA tonight, while the front forecast to stall out again over
Mendocino and southern Trinity late tonight, which should inhibit
fog development for the southern half of the CWA.

&&

.MARINE...A quasi-stationary front has set up off the southern
Oregon coast overnight, with advisory level southerlies persisting
in the northern waters early this morning, while southerlies are
expected to increase through the day today in the southern waters.
This front is forecast to slide southward through the day today,
reaching Pt. Arena by early Wednesday morning. Gusts over 30 kts
will be possible with the passing of the front. High pressure and
northerly winds will return behind this feature and persist through
Thursday. A brief period of sub-advisory winds is possible for the
northern waters, as initially the strongest northerlies appear to be
further offshore. However this wind core is forecast to slide toward
the coast late tonight and early Wednesday, likely bringing winds
back over 20 kts with some localized areas of low-end Gale Force
gusts possible Wednesday afternoon. Northerlies weaken a hair
Wednesday night then restrengthen Thursday afternoon, primarily
south of Cape Mendocino as ridging builds over southern Oregon.
Waves remain primarily locally-dominated, although a small west
swell moves through over the next couple of days. Short period
northerly seas filter out by later this week, then a more solid west
swell is forecast to fill in this weekend...accompanied by a return
of southerlies with another frontal passage.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Storm Warning until 4 PM PST this afternoon for
     CAZ107-108.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PST this morning for PZZ450-
     470.

     Small Craft Advisory until 3 PM PST this afternoon for
     PZZ455-475.

&&

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

Preliminary Local Storm Report
National Weather Service Eureka CA
858 AM PST Tue Mar 5 2024

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

0839 AM     Landslide        6 E Gasquet             41.86N 123.86W
03/05/2024                   Del Norte          CA   Law Enforcement

            Rocks over road.

&&

Preliminary Local Storm Report
National Weather Service Eureka CA
1035 AM PST Tue Mar 5 2024

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

0902 AM     Rain             5 SSE Honeydew          40.16N 124.09W
03/05/2024  M4.75 inch       Humboldt           CA   Public

            A total rainfall of 4.75 inches fell over
            the past 15 hours. 105 inches for the water
            year so far.

&&

MH

Preliminary Local Storm Report
National Weather Service Eureka CA
1111 AM PST Tue Mar 5 2024

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

1056 AM     Landslide        4 WSW Gasquet           41.82N 124.04W
03/05/2024                   Del Norte          CA   Law Enforcement

            Highway 199 LOOKS TO HAVE DROPPED 2-3
            INCHES.

&&

MH

Preliminary Local Storm Report
National Weather Service Eureka CA
1119 AM PST Tue Mar 5 2024

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

1111 AM     Landslide        4 WSW Gasquet           41.82N 124.04W
03/05/2024                   Del Norte          CA   Law Enforcement

            Rocks on Highway 199.

&&

MH

Preliminary Local Storm Report
National Weather Service Eureka CA
1157 AM PST Tue Mar 5 2024

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

1140 AM     Landslide        5 SW Douglas City       40.60N 123.01W
03/05/2024                   Trinity            CA   Law Enforcement

            Vehicle sized boulder in road.

&&

MH

Preliminary Local Storm Report
National Weather Service Eureka CA
113 PM PST Tue Mar 5 2024

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

1249 PM     Flood            1 SSE Shively           40.42N 123.96W
03/05/2024                   Humboldt           CA   Law Enforcement

            Roadway closed due to flooding on Avenue of
            the Giants (Highway 254) near junction of
            Holmes Flat Rd.

&&

MH