Alert archive / California / High Surf Warnings in 2021

High Surf Warning 1, NWS Eureka, CA

January 9, 2021Del Norte County, Humboldt County, Mendocino County, California

NWS Eureka, CA issued this high surf warning at Jan 9, 2021, 4:39 AM PST for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Jan 10, 2021, 3:00 AM PST. It was in force for 15 hr. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jan 9, 2021, 4:39 AM PST (12:39 UTC)
In effect from
Jan 10, 2021, 3:00 AM PST
Expired
Jan 10, 2021, 6:00 PM PST
In force
15 hr
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA, Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 47 km from the middle of the area, began a volume at 12:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jan 10, 8:45 AM PSTHIGH SURF1 Sw Westhaven-Moonston, CALARGE WAVES WASHED INTO THE PARKING LOT AT MOONSTONE BEACH.
Jan 10, 8:45 AM PSTHIGH SURF1 Wsw Fairhaven, CAWAVES WASHING ONTO NEW NAVY BASE ROAD JUST BEFORE THE COAST GUARD STATION IN SEVERAL LOCATIONS.
Jan 10, 8:45 AM PSTHIGH SURF5 W Ferndale, CALARGE SURF IS COMING OVER CENTERVILLE BEACH ROAD AND PUSHING SAND ONTO THE ROAD. ROAD IS CURRENTLY CLOSED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 12:00Z, 0.7 hours before the alert went out and 210 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Medford/Jackson, OR at 12:00Z on 2021-01-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2021-01-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -56 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-56 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

151 
WHUS46 KEKA 091239
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
439 AM PST Sat Jan 9 2021

CAZ101-092045-
/O.NEW.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Coastal Del Norte-
439 AM PST Sat Jan 9 2021

...HIGH SURF WARNING IN EFFECT FROM 3 AM TO 6 PM PST SUNDAY...
...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE TONIGHT
THROUGH SUNDAY MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 28 to 30 feet. For the Coastal Flood Watch, high
  astronomical tides combined with the high surf may result in up
  to one foot of saltwater inundation above ground level in low 
  lying areas near shorelines and tidal waterways (between 8.7 and
  8.9 feet MLLW at the Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST Sunday.
  For the Coastal Flood Watch, from late tonight through Sunday
  morning.

* IMPACTS...Highway 101 at South Beach may see waves break over
  the road at high tide. Any low lying property in this area may 
  be inundated. Some shoreline erosion may occur. Breaking waves 
  can sweep people off jetties and docks, and into dangerous seas.
  Life-threatening surfing conditions and significant beach 
  erosion can be expected.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-104-092045-
/O.NEW.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Northern Humboldt Coast-Southwestern Humboldt-
439 AM PST Sat Jan 9 2021

...HIGH SURF WARNING IN EFFECT FROM 3 AM TO 6 PM PST SUNDAY...
...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE TONIGHT
THROUGH SUNDAY MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 28 to 30 feet. For the Coastal Flood Watch, high
  astronomical tides combined with the high surf may result in up
  to one foot of saltwater inundation above ground level in low
  lying areas near shorelines and tidal waterways (between 8.8 and
  9.0 feet MLLW at the North Spit tide gauge).

* WHERE...Coastal Humboldt County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST Sunday.
  For the Coastal Flood Watch, from late tonight through Sunday
  morning.

* IMPACTS...Centerville Beach Road, New Navy Base Road and
  possibly other exposed coastal roads may see waves break over
  the road at high tide. Other low-lying roads around King Salmon
  and the Arcata Bottoms may be partially inundated. Some 
  shoreline erosion may occur. Breaking waves can sweep people off
  jetties and docks, and into dangerous seas. Life- threatening 
  surfing conditions and significant beach erosion can be 
  expected.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-092045-
/O.NEW.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Mendocino Coast-
439 AM PST Sat Jan 9 2021

...HIGH SURF WARNING IN EFFECT FROM 3 AM TO 6 PM PST SUNDAY...

* WHAT...Dangerously large breaking waves of 26 to 28 feet. 

* WHERE...Coastal Mendocino County.

* WHEN...From 3 AM to 6 PM PST Sunday.

* IMPACTS...Breaking waves can sweep people off jetties and docks,
  and into dangerous seas. Life-threatening surfing conditions and
  significant beach erosion can be expected. Additionally, be
  aware of high astronomical tides Sunday morning, allowing some
  of the breaking waves to wash much farther up beaches and
  possibly approaching some low-lying beach-side roadways. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
6 follow-up statements
227 
WHUS46 KEKA 091613
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
813 AM PST Sat Jan 9 2021

CAZ101-100015-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Coastal Del Norte-
813 AM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE TONIGHT
THROUGH SUNDAY MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 28 to 30 feet. For the Coastal Flood Watch, high
  astronomical tides combined with the high surf may result in up
  to a half foot of saltwater inundation above ground level in 
  low lying areas near shorelines and tidal waterways (between 8.7
  and 8.9 feet MLLW at the Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST 
  Sunday. For the Coastal Flood Watch, from late tonight through 
  Sunday morning.

* IMPACTS...Highway 101 at South Beach may see waves break over 
  the road at high tide. Any low lying property in this area may 
  be inundated. Some shoreline erosion may occur. Breaking waves 
  can sweep people off jetties and docks, and into dangerous 
  seas. Life- threatening surfing conditions and significant 
  beach erosion can be expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-104-100015-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Northern Humboldt Coast-Southwestern Humboldt-
813 AM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE TONIGHT
THROUGH SUNDAY MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 28 to 30 feet. For the Coastal Flood Watch, high
  astronomical tides combined with the high surf may result in up
  to a half foot of saltwater inundation above ground level in 
  low lying areas near shorelines and tidal waterways (between 8.8
  and 9.0 feet MLLW at the North Spit tide gauge).

* WHERE...Coastal Humboldt County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST 
  Sunday. For the Coastal Flood Watch, from late tonight through 
  Sunday morning.

* IMPACTS...Centerville Beach Road, New Navy Base Road and
  possibly other exposed coastal roads may see waves break over
  the road at high tide. Other low-lying roads around King Salmon
  and the Arcata Bottoms may be partially inundated. Some
  shoreline erosion may occur. Breaking waves can sweep people off
  jetties and docks, and into dangerous seas. Life- threatening
  surfing conditions and significant beach erosion can be
  expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-100015-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Mendocino Coast-
813 AM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...

* WHAT...Dangerously large breaking waves of 26 to 28 feet.

* WHERE...Coastal Mendocino County.

* WHEN...From 3 AM to 6 PM PST Sunday.

* IMPACTS...Breaking waves can sweep people off jetties and docks,
  and into dangerous seas. Life-threatening surfing conditions and
  significant beach erosion can be expected. 

* ADDITIONAL DETAILS...Be aware of high astronomical tides Sunday
  morning, allowing some of the breaking waves to wash much
  farther up beaches and possibly over some low-lying beach-side
  roadways or parking lots.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
819 
WHUS46 KEKA 092224
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
224 PM PST Sat Jan 9 2021

...Very large surf and high tides Sunday morning...

Late tonight large long period waves will bring large breaking surf
to the coast. These breakers are expected to peak Sunday morning 
about 30 feet and slowly diminish in the afternoon evening. This 
will coincide with a high astronomical tide and small amount of 
surge to produce some minor coastal flooding. Large waves may wash
over vulnerable coastal roads. 


CAZ104-100630-
/O.CAN.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Southwestern Humboldt-
224 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD WATCH IS CANCELLED...

* WHAT...Dangerously large breaking waves of 28 to 30 feet.

* WHERE...Southwestern Humboldt County.

* WHEN...From 3 AM to 6 PM PST Sunday.. .

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ101-100630-
/O.UPG.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
/O.NEW.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Coastal Del Norte-
224 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 7 AM TO 11 AM PST
SUNDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides combined with high surf will cause minor
  flooding in low lying areas along the Del Norte Coast. Up to one
  half foot of saltwater inundation above ground level is possible
  in low lying areas near shorelines and tidal waterways (Between
  8.7 and 8.9 feet MLLW at the Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST Sunday.
  For the Coastal Flood Advisory, from 7 AM to 11 AM PST Sunday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures expected. This may include Anchor Way near the
  Crescent City Harbor. Breaking waves can sweep people off 
  jetties and docks, and into dangerous seas. Life-threatening 
  surfing conditions and significant beach erosion can be 
  expected. 

* ADDITIONAL DETAILS...It is possible a few waves will break onto
  the edge of Highway 101 at South Beach near Crescent City. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-100630-
/O.UPG.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
/O.NEW.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Northern Humboldt Coast-
224 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 7 AM TO 11 AM PST
SUNDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides will cause minor flooding in low lying areas
  along the Redwood Coast. Up to one half foot of saltwater
  inundation above ground level is possible in low lying areas
  near shorelines and tidal waterways (Between 8.8 and 9.0 feet
  MLLW at the North spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST 
  Sunday. For the Coastal Flood Advisory, from 7 AM to 11 AM PST 
  Sunday.. .

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures expected. Breaking waves can sweep people off 
  jetties and docks, and into dangerous seas. Life- threatening 
  surfing conditions and significant beach erosion can be 
  expected.

* ADDITIONAL DETAILS...The low lying areas around King Salmon and
  in the Arcata Bottoms may see minor saltwater flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-100630-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Mendocino Coast-
224 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...

* WHAT...Dangerously large breaking waves 25 to 30 feet.

* WHERE...Mendocino Coast County.

* WHEN...From 3 AM to 6 PM PST Sunday.. .

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...It is possible a few of the largest waves
  may reach parking lots or minor roads very close to sea level.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
958 
WHUS46 KEKA 100449
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
849 PM PST Sat Jan 9 2021

...Very large surf and high tides Sunday morning...

Large long period waves will bring large breaking surf to the 
coast late tonight. These breakers are expected to peak during Sunday
at around 30 feet and slowly diminish in the evening. Large waves
will coincide with a high astronomical tide in the morning, along
with a small amount of surge, to produce some minor coastal 
flooding. Large waves may wash over vulnerable coastal roads as 
well.

CAZ101-101300-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
Coastal Del Norte-
849 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 7 AM TO 11 AM
PST SUNDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides combined with high surf will cause minor
  flooding in low lying areas along the Del Norte Coast. Up to one
  half foot of saltwater inundation above ground level is possible
  in low lying areas near shorelines and tidal waterways (Between
  8.7 and 8.9 feet MLLW at the Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST 
  Sunday. For the Coastal Flood Advisory, from 7 AM to 11 AM PST 
  Sunday.. .

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening surfing conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...It is possible a few waves will break onto
  the edge of Highway 101 at South Beach near Crescent City. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-101300-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
/O.CON.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
Northern Humboldt Coast-
849 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 7 AM TO 11 AM
PST SUNDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides will cause minor flooding in low lying areas
  along the Redwood Coast. Up to one half foot of saltwater
  inundation above ground level is possible in low lying areas
  near shorelines and tidal waterways (Between 8.8 and 9.0 feet
  MLLW at the North spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST 
  Sunday. For the Coastal Flood Advisory, from 7 AM to 11 AM PST 
  Sunday.. .

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening surfing conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...The low lying areas around King Salmon and
  in the Arcata Bottoms may see minor saltwater flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-109-101300-
/O.CON.KEKA.SU.W.0001.210110T1100Z-210111T0200Z/
Southwestern Humboldt-Mendocino Coast-
849 PM PST Sat Jan 9 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM TO 6 PM PST
SUNDAY...

* WHAT...Dangerously large breaking waves 25 to 30 feet.

* WHERE...Mendocino Coast and Southwestern Humboldt Counties.

* WHEN...From 3 AM to 6 PM PST Sunday.. .

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...It is possible a few of the largest waves
  may reach parking lots or minor roads very close to sea level.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
829 
WHUS46 KEKA 101203
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
403 AM PST Sun Jan 10 2021

...Very large surf and high tides Sunday morning...

Large long period waves will bring large breaking surf to the
coast today, peaking at around 30 feet and slowly diminishing in 
the evening. Large waves will coincide with a high astronomical 
tide this morning, along with a small amount of surge, to produce
some minor coastal flooding. Large waves may wash over vulnerable
coastal roads as well.

CAZ101-102015-
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
/O.CON.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
Coastal Del Norte-
403 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 7 AM TO 11 AM
PST THIS MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides combined with high surf may cause minor
  flooding in low lying areas along the Del Norte Coast,
  particularly around South Beach. Up to one half foot of 
  saltwater inundation above ground level is possible in low lying
  areas near shorelines and tidal waterways (Between 8.0 and 8.2 
  feet MLLW at the Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST Sunday.
  For the Coastal Flood Advisory, from 7 AM to 11 AM PST Sunday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  lane or road closures possible, mainly in the vicinity of South
  beach near Crescent City. Breaking waves can sweep people off 
  jetties and docks, and into dangerous seas. Life- threatening 
  surfing conditions and significant beach erosion can be 
  expected.

* ADDITIONAL DETAILS...It is possible a few waves will break 
  onto the edge of Highway 101 at South Beach near Crescent City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-102015-
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
/O.CON.KEKA.CF.Y.0001.210110T1500Z-210110T1900Z/
Northern Humboldt Coast-
403 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 7 AM TO 11 AM
PST THIS MORNING...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides will cause minor flooding in low lying areas
  along the Redwood Coast. Up to one half foot of saltwater
  inundation above ground level is possible in low lying areas
  near shorelines where waves wash over. (Between 8.5 and 8.7 
  feet MLLW at the North spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Warning, from 3 AM to 6 PM PST Sunday.
  For the Coastal Flood Advisory, from 7 AM to 11 AM PST Sunday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures possible. Breaking waves can sweep people off 
  jetties and docks, and into dangerous seas. Life- threatening 
  surfing conditions and significant beach erosion can be 
  expected.

* ADDITIONAL DETAILS...Vulnerable spots like the road near
  Centerville Beach and the lowest-lying portions of New Navy Base
  Road past Fairhaven may see waves wash up to the roadway. The 
  low lying areas around King Salmon and in the Arcata Bottoms may
  see very minor saltwater flooding.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-109-102015-
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Southwestern Humboldt-Mendocino Coast-
403 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...

* WHAT...Dangerously large breaking waves 25 to 30 feet.

* WHERE...Mendocino Coast and Southwestern Humboldt Counties.

* WHEN...From 3 AM to 6 PM PST Sunday.

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...It is possible a few of the largest waves
  may reach beach parking lots or roads very close to sea level.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
730 
WHUS46 KEKA 101849
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
1049 AM PST Sun Jan 10 2021

...Very large surf and high tides Sunday morning...

Large long period waves will bring large breaking surf to the
coast today, peaking at around 30 feet and slowly diminishing in
the evening. Large waves will coincide with a high astronomical
tide this morning, along with a small amount of surge, to produce
some minor coastal flooding. Large waves may wash over vulnerable
coastal roads as well.

CAZ101-110200-
/O.EXP.KEKA.CF.Y.0001.000000T0000Z-210110T1900Z/
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Coastal Del Norte-
1049 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...
...COASTAL FLOOD ADVISORY WILL EXPIRE AT 11 AM PST THIS MORNING...

* WHAT...Dangerously large breaking waves 28 to 30 feet.
  
* WHERE...Coastal Del Norte County.

* WHEN...From 3 AM to 6 PM PST Sunday. Waves will peak midday and
  diminish through the afternoon. 

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...Larger sets of waves are possible at any 
  times, stay off rocks and jetties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-110200-
/O.EXP.KEKA.CF.Y.0001.000000T0000Z-210110T1900Z/
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Northern Humboldt Coast-
1049 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...
...COASTAL FLOOD ADVISORY WILL EXPIRE AT 11 AM PST THIS MORNING...

* WHAT...Dangerously large breaking waves 28 to 30 feet.

* WHERE...Northern Humboldt Coast County.

* WHEN...From 3 AM to 6 PM PST Sunday. Waves will peak midday and
  diminish through the afternoon. 

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...Larger sets of waves are possible at any 
  times, stay off rocks and jetties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-109-110200-
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Southwestern Humboldt-Mendocino Coast-
1049 AM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...

* WHAT...Dangerously large breaking waves 25 to 30 feet.

* WHERE...Mendocino Coast and Southwestern Humboldt Counties.

* WHEN...From 3 AM to 6 PM PST Sunday. Waves will peak midday and
  diminish through the afternoon. 

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...Larger sets of waves are possible at any 
  times, stay off rocks and jetties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
838 
WHUS46 KEKA 102212
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
212 PM PST Sun Jan 10 2021

...High tides Monday morning...

Large long period waves will bring large breaking surf will slowly
diminish tonight. Southerly winds will continue and will elevate
tide levels inside Humboldt Bay. This will likely cause minor
flooding around the Bay.

Strong winds, large surf and high tides will likely bring another
round of coastal flooding Tuesday. Large waves may wash over 
vulnerable coastal roads again.

CAZ103-110615-
/O.NEW.KEKA.CF.Y.0002.210111T1600Z-210111T1900Z/
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Northern Humboldt Coast-
212 PM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 8 AM TO 11 AM PST
MONDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves 25 to 30 feet. For the Coastal Flood Advisory, High
  astronomical tides will cause minor flooding in low lying areas
  along the Redwood Coast. Up to one half foot of saltwater
  inundation above ground level is possible in low lying areas
  near shorelines and tidal waterways (Between 8.8 and 8.9 feet
  MLLW at the North Spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Warning, until 6 PM PST this evening.
  For the Coastal Flood Advisory, from 8 AM to 11 AM PST Monday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening surfing conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Monday morning coastal flooding is expected
  on Jackson Ranch road in the Arcata Bottoms and in King Salmon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ101-104-109-110200-
/O.CON.KEKA.SU.W.0001.000000T0000Z-210111T0200Z/
Coastal Del Norte-Southwestern Humboldt-Mendocino Coast-
212 PM PST Sun Jan 10 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS
EVENING...

* WHAT...Dangerously large breaking waves 24 to 28 feet.

* WHERE...Coastal Del Norte, Mendocino Coast and Southwestern 
  Humboldt Counties.

* WHEN...Until 6 PM PST this evening.. .

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening surfing 
  conditions and significant beach erosion can be expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

The office that day

Everything else NWS Eureka, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 9, 12:02 PM PSTSmall Craft AdvisoryEKA15 hr
Jan 9, 12:02 PM PSTHazardous Seas WarningEKA33 hr
Jan 9, 2:24 PM PSTCoastal Flood AdvisoryEKADel Norte, Humboldt21 hr

Nearby

High Surf Warnings in California, 2021Every high surf warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.