Alert archive / California / High Surf Advisories in 2021

High Surf Advisory 4, NWS Eureka, CA

January 7, 2021Del Norte County, Humboldt County, Mendocino County, California

NWS Eureka, CA issued this high surf advisory at Jan 7, 2021, 3:16 AM PST for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Jan 8, 2021, 4:00 AM PST. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Jan 7, 2021, 3:16 AM PST (11:16 UTC)
In effect from
Jan 8, 2021, 4:00 AM PST
Expired
Jan 8, 2021, 10:00 PM PST
In force
18 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 11:21 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 11.3 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 00:00Z on 2021-01-07Temperature 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 00:00Z on 2021-01-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 138 square meters per square second.1939587897Sfc1 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
850 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
138 m²/s²
0-3 km storm-relative helicity
234 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

348 
WHUS46 KEKA 071116
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
316 AM PST Thu Jan 7 2021

CAZ101-103-104-109-071930-
/O.NEW.KEKA.SU.Y.0004.210108T1200Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
316 AM PST Thu Jan 7 2021

...HIGH SURF ADVISORY IN EFFECT FROM 4 AM TO 10 PM PST FRIDAY...

* WHAT...Large breaking waves 20 to 23 feet.

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

* WHEN...From 4 AM to 10 PM PST Friday.

* 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
776 
WHUS46 KEKA 071647
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
847 AM PST Thu Jan 7 2021

CAZ101-103-104-109-080100-
/O.CON.KEKA.SU.Y.0004.210108T1200Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
847 AM PST Thu Jan 7 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 4 AM TO 10 PM PST
FRIDAY...

* WHAT...Large breaking waves 20 to 23 feet

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

* WHEN...From 4 AM to 10 PM PST Friday.. .

* 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.

&&

$$
272 
WHUS46 KEKA 072243
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
243 PM PST Thu Jan 7 2021

CAZ101-103-104-109-080600-
/O.CON.KEKA.SU.Y.0004.210108T1200Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
243 PM PST Thu Jan 7 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 4 AM TO 10 PM PST
FRIDAY...

* WHAT...Large breaking waves 21 to 23 feet.

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

* WHEN...From 4 AM to 10 PM PST Friday.. .

* 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.

&&

$$
887 
WHUS46 KEKA 080501
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
901 PM PST Thu Jan 7 2021

CAZ101-103-104-109-081200-
/O.CON.KEKA.SU.Y.0004.210108T1200Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
901 PM PST Thu Jan 7 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 4 AM TO 10 PM PST
FRIDAY...

* WHAT...Large breaking waves 20 to 22 feet.

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

* WHEN...From 4 AM to 10 PM PST Friday.. .

* 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.

&&

$$
220 
WHUS46 KEKA 081149
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
349 AM PST Fri Jan 8 2021

CAZ101-103-104-109-082000-
/O.CON.KEKA.SU.Y.0004.210108T1200Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
349 AM PST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...

* WHAT...Large breaking waves 20 to 23 feet.

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

* WHEN...Until 10 PM PST this evening.

* 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.

&&

$$
639 
WHUS46 KEKA 081641
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
841 AM PST Fri Jan 8 2021

CAZ101-103-104-109-090045-
/O.CON.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
Coastal Del Norte-Northern Humboldt Coast-Southwestern Humboldt-
Mendocino Coast-
841 AM PST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...

* WHAT...Large breaking waves 20 to 23 feet.

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

* WHEN...Until 10 PM PST this evening.. .

* 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.

&&

$$
982 
WHUS46 KEKA 082221
CFWEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Coastal Hazard Message
National Weather Service Eureka CA
221 PM PST Fri Jan 8 2021

CAZ101-090630-
/O.NEW.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
/O.CON.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
Coastal Del Norte-
221 PM PST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...
...COASTAL FLOOD WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING...

* WHAT...For the High Surf Advisory, large breaking waves of 20 to
  23 feet. For the Coastal Flood Watch, breaking waves of 28 to 30
  feet and high astronomical tides. Up to a half foot of saltwater
  inundation is possible above sea level.

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Advisory, until 10 PM PST this evening.
  For the Coastal Flood Watch, from late Saturday night through
  Sunday morning.

* IMPACTS...For the high Surf Watch, Highway 101 at South Beach
  may see waves break across it at high tide. Low lying property
  including homes, businesses, and some critical infrastructure
  may be inundated. For the High Surf Advisory, some shoreline
  erosion may occur. Dangerous surfing conditions and localized
  beach erosion. Beachcombing is highly discouraged!

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.

&&

$$

CAZ103-104-090630-
/O.NEW.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
/O.CON.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
Northern Humboldt Coast-Southwestern Humboldt-
221 PM PST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...
...COASTAL FLOOD WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING...

* WHAT...For the High Surf Advisory, large breaking waves of 19 to
  22 feet. For the Coastal Flood Watch, large breaking waves of 
  28 to 30 feet.

* WHERE...Humboldt County Coast.

* WHEN...For the High Surf Advisory, until 10 PM PST this evening.
  For the Coastal Flood Watch, from late Saturday night through
  Sunday morning. Up to a half foot of saltwater inundation is
  possible above sea level.

* IMPACTS...For the high Surf Watch, Centerville Beach Road, New
  Navy Base Road and possibly other exposed coastal roads may see
  waves break across it at high tide. Low lying property 
  including homes, businesses, and some critical infrastructure 
  may be inundated. For the High Surf Advisory, some shoreline 
  erosion may occur. Dangerous surfing conditions and localized 
  beach erosion. Beachcombing is highly discouraged!

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.

&&

$$

CAZ109-090600-
/O.CON.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
Mendocino Coast-
221 PM PST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS
EVENING...

* WHAT...Large breaking waves 19 to 22 feet. 

* WHERE...Mendocino Coast County.

* WHEN...Until 10 PM PST this evening.. .

* 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.

&&

$$
364 
WHUS46 KEKA 090604
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
1004 PM PST Fri Jan 8 2021

CAZ101-091415-
/O.EXP.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Coastal Del Norte-
1004 PM PST Fri Jan 8 2021

...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING...
...HIGH SURF ADVISORY HAS EXPIRED...

* WHAT...Breaking waves of 28 to 30 feet and high astronomical 
  tides. Up to a half foot of saltwater inundation is possible 
  above sea level.

* WHERE...Coastal Del Norte.

* WHEN...From late Saturday night through Sunday morning.. .

* IMPACTS...Highway 101 at South Beach may see waves break over
  the road at high tide. Low lying property including homes, 
  businesses, and some critical infrastructure may be inundated.

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.

&&

$$

CAZ103-104-091415-
/O.EXP.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
/O.CON.KEKA.CF.A.0001.210110T1100Z-210110T1800Z/
Northern Humboldt Coast-Southwestern Humboldt-
1004 PM PST Fri Jan 8 2021

...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING...
...HIGH SURF ADVISORY HAS EXPIRED...

* WHAT...Large breaking waves of 28 to 30 feet.

* WHERE...Humboldt Coast.

* WHEN...From late Saturday night 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. Low lying property including homes, 
  businesses, and some critical infrastructure may be inundated.

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.

&&

$$

CAZ109-090715-
/O.EXP.KEKA.SU.Y.0004.000000T0000Z-210109T0600Z/
Mendocino Coast-
1004 PM PST Fri Jan 8 2021

...HIGH SURF ADVISORY HAS EXPIRED...

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 6, 8:48 PM PSTGale WarningEKA30 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.