Alert archive / California / High Surf Advisories in 2021

High Surf Advisory 6, NWS Eureka, CA

October 22, 2021Mendocino County, California

NWS Eureka, CA issued this high surf advisory at Oct 22, 2021, 9:02 PM PDT for Mendocino County, California. It took effect at Oct 24, 2021, 5:00 PM PDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Oct 22, 2021, 9:02 PM PDT (04:02 UTC)
In effect from
Oct 24, 2021, 5:00 PM PDT
Expired
Oct 25, 2021, 12:32 AM PDT
In force
8 hr
Issued by
NWS Eureka, CA

County Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 139 km from the middle of the area, began a volume at 04:02 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.

The nearest sounding before it

Oakland, CA (KOAK), launched 00:00Z, 4.0 hours before the alert went out and 218 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, Oakland, CA at 00:00Z on 2021-10-23Temperature 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, Oakland, CA at 00:00Z on 2021-10-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
880 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

725 
WHUS46 KEKA 230402
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
902 PM PDT Fri Oct 22 2021

CAZ101-103-104-231130-
/O.NEW.KEKA.SU.W.0002.211025T0400Z-211026T0400Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
902 PM PDT Fri Oct 22 2021

...HIGH SURF WARNING IN EFFECT FROM 9 PM SUNDAY TO 9 PM PDT
MONDAY...

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

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

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* 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.

&&

$$

CAZ109-231130-
/O.NEW.KEKA.SU.Y.0006.211025T0400Z-211026T0400Z/
Mendocino Coast-
902 PM PDT Fri Oct 22 2021

...HIGH SURF ADVISORY IN EFFECT FROM 9 PM SUNDAY TO 9 PM PDT
MONDAY...

* WHAT...Large breaking waves up to 25 feet.

* WHERE...Mendocino Coast County.

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

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.

&&

$$
7 follow-up statements
058 
WHUS46 KEKA 231130
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
430 AM PDT Sat Oct 23 2021

CAZ101-103-104-232200-
/O.CON.KEKA.SU.W.0002.211025T0400Z-211026T0400Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
430 AM PDT Sat Oct 23 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
MONDAY...

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

* WHERE...Del Norte and Humboldt county coast.

* WHEN...From 9 PM Sunday to 9 PM Monday.

* 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 Coast Guard for information regarding harbor and bar closures.

$$

CAZ109-232200-
/O.CON.KEKA.SU.Y.0006.211025T0400Z-211026T0400Z/
Mendocino Coast-
430 AM PDT Sat Oct 23 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
MONDAY...

* WHAT...Large breaking waves up to 25 feet.

* WHERE...Mendocino Coast County.

* WHEN...From 9 PM Sunday to 9 PM Monday.. .

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

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 Coast Guard for information regarding harbor and bar 
closures.

$$
973 
WHUS46 KEKA 232150
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
250 PM PDT Sat Oct 23 2021

CAZ101-103-104-240600-
/O.CON.KEKA.SU.W.0002.211025T0400Z-211026T0400Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
250 PM PDT Sat Oct 23 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
PDT MONDAY...

* WHAT...Dangerously large breaking waves up to 30ft especially
  around headlands 

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

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* 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.

&&

$$

CAZ109-240600-
/O.CON.KEKA.SU.Y.0006.211025T0400Z-211026T0400Z/
Mendocino Coast-
250 PM PDT Sat Oct 23 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
PDT MONDAY...

* WHAT...Large breaking waves up to 26ft especially around 
  headlands 

* WHERE...Mendocino Coast County.

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

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.

&&

$$
867 
WHUS46 KEKA 240333
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
833 PM PDT Sat Oct 23 2021

CAZ101-103-104-241145-
/O.CON.KEKA.SU.W.0002.211025T0400Z-211026T0400Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
833 PM PDT Sat Oct 23 2021

...HIGH SURF WARNING REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
PDT MONDAY...

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

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

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* 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.

&&

$$

CAZ109-241145-
/O.CON.KEKA.SU.Y.0006.211025T0400Z-211026T0400Z/
Mendocino Coast-
833 PM PDT Sat Oct 23 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 9 PM SUNDAY TO 9 PM
PDT MONDAY...

* WHAT...Large breaking waves up to around 25 feet.

* WHERE...Mendocino Coast County.

* WHEN...From 9 PM Sunday to 9 PM PDT Monday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

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.

&&

$$
297 
WHUS46 KEKA 241135
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
435 AM PDT Sun Oct 24 2021

CAZ101-103-104-242200-
/O.EXT.KEKA.SU.W.0002.211025T0000Z-211026T0300Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
435 AM PDT Sun Oct 24 2021

...HIGH SURF WARNING NOW IN EFFECT FROM 5 PM THIS AFTERNOON TO
8 PM MONDAY...

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

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

* WHEN...From 5 PM this afternoon to 8 PM Monday.

* 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 Coast Guard for information regarding harbor and bar 
closures.

$$

CAZ109-242200-
/O.EXT.KEKA.SU.Y.0006.211025T0000Z-211026T0300Z/
Mendocino Coast-
435 AM PDT Sun Oct 24 2021

...HIGH SURF ADVISORY NOW IN EFFECT FROM 5 PM THIS AFTERNOON TO
8 PM MONDAY...

* WHAT...Large breaking waves up to 25 feet.

* WHERE...Mendocino Coast.

* WHEN...From 5 PM this afternoon to 8 PM Monday.

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

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 Coast Guard for information regarding harbor and bar 
closures.

$$
460 
WHUS46 KEKA 242153
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
253 PM PDT Sun Oct 24 2021

CAZ101-103-104-250600-
/O.CON.KEKA.SU.W.0002.211025T0000Z-211026T0300Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
253 PM PDT Sun Oct 24 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 8 PM PDT MONDAY...

* WHAT...Dangerously large breaking waves 26 to 30ft.

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

* WHEN...Until 8 PM PDT Monday.. .

* 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.

&&

$$

CAZ109-250600-
/O.CON.KEKA.SU.Y.0006.211025T0000Z-211026T0300Z/
Mendocino Coast-
253 PM PDT Sun Oct 24 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 PM PDT MONDAY...

* WHAT...Large breaking waves 22 to 26ft.

* WHERE...Mendocino Coast County.

* WHEN...Until 8 PM PDT Monday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

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.

&&

$$
158 
WHUS46 KEKA 250439
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
939 PM PDT Sun Oct 24 2021

CAZ101-103-104-251230-
/O.EXT.KEKA.SU.W.0002.000000T0000Z-211026T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
939 PM PDT Sun Oct 24 2021

...HIGH SURF WARNING NOW IN EFFECT UNTIL 11 PM PDT MONDAY...

* WHAT...Dangerously large breaking waves 26 to 30 feet. 

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

* WHEN...Until 11 PM PDT Monday. Highest waves will be overnight
  into Monday morning. 

* 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.

&&

$$

CAZ109-251230-
/O.EXT.KEKA.SU.Y.0006.000000T0000Z-211026T0600Z/
Mendocino Coast-
939 PM PDT Sun Oct 24 2021

...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 11 PM PDT MONDAY...

* WHAT...Large breaking waves 22 to 26 feet. 

* WHERE...Mendocino Coast County.

* WHEN...Until 11 PM PDT Monday. Highest wave heights will occur
  early Monday morning. 

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

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.

&&

$$
664 
WHUS46 KEKA 250732
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
1232 AM PDT Mon Oct 25 2021

CAZ109-251545-
/O.UPG.KEKA.SU.Y.0006.000000T0000Z-211026T0600Z/
/O.EXA.KEKA.SU.W.0002.000000T0000Z-211026T0600Z/
Mendocino Coast-
1232 AM PDT Mon Oct 25 2021

...HIGH SURF WARNING IN EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Dangerously large breaking waves over 30 feet. 

* WHERE...Mendocino Coast County.

* WHEN...Until 11 PM PDT 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.

&&

$$

CAZ101-103-104-251545-
/O.CON.KEKA.SU.W.0002.000000T0000Z-211026T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
1232 AM PDT Mon Oct 25 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING...

* WHAT...Dangerously large breaking waves approaching 30 feet.

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

* WHEN...Until 11 PM PDT 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
Oct 22, 9:02 PM PDTHigh Surf WarningEKADel Norte, Humboldt, Mendocino68 hr
Oct 23, 2:59 AM PDTGale WarningEKA32 hr
Oct 23, 2:47 PM PDTHazardous Seas WarningEKA60 hr

Nearby

High Surf Advisories in California, 2021Every high surf advisory 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.