Alert archive / California / High Surf Advisories in 2017

High Surf Advisory 5, NWS Eureka, CA

October 18, 2017Del Norte County, Humboldt County, Mendocino County, California

NWS Eureka, CA issued this high surf advisory at Oct 18, 2017, 6:16 AM PDT for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Oct 19, 2017, 5:00 PM PDT. It was in force for 25 hr.

The area

The counties it named.

The facts

Issued
Oct 18, 2017, 6:16 AM PDT (13:16 UTC)
In effect from
Oct 19, 2017, 5:00 PM PDT
Expired
Oct 20, 2017, 6:00 PM PDT
In force
25 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 13:18 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 12:00Z, 1.3 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 12:00Z on 2017-10-18Temperature 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 2017-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.193958Sfc1 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
1795 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

521 
WHUS46 KEKA 181316 CCA
CFWEKA

COASTAL HAZARD MESSAGE...CORRECTED
NATIONAL WEATHER SERVICE EUREKA CA
616 AM PDT WED OCT 18 2017

...HIGH SURF EXPECTED THURSDAY NIGHT THROUGH FRIDAY...

.A HUGE NORTHWEST SWELL AROUND 20 FEET WITH PERIODS NEAR 17 
SECONDS WILL SPREAD INTO THE COASTAL WATERS THURSDAY NIGHT. THE
HUGE SWELL WILL PERSIST THROUGH THE DAY ON FRIDAY RESULTING IN 
BREAKERS OF 23 TO 25 FEET IN THE SURF ZONE. THIS WILL POSE A 
THREAT TO BEACH GOERS AND MARINERS TRAVERSING HARBOR ENTRANCES.


CAZ101-103-104-109-182230-
/O.NEW.KEKA.SU.Y.0001.171020T0100Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
616 AM PDT WED OCT 18 2017

...HIGH SURF ADVISORY IN EFFECT FROM 6 PM THURSDAY TO 6 PM PDT
FRIDAY...

THE NATIONAL WEATHER SERVICE IN EUREKA HAS ISSUED A HIGH SURF
ADVISORY...WHICH IS IN EFFECT FROM 6 PM THURSDAY TO 6 PM PDT
FRIDAY. 

* WAVES AND SURF...BREAKING WAVES 22 TO 25 FEET ALONG WEST AND 
  NORTHWEST FACING BEACHES.

* IMPACTS...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 ESPECIALLY DURING MAX EBB WHICH IS
  PREDICTED TO OCCUR AROUND 3:30 AM AND 4:00 PM FRIDAY...OR STAY 
  IN PORT UNTIL THE THREAT SUBSIDES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

&&

$$
8 follow-up statements
526 
WHUS46 KEKA 182237
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
337 PM PDT WED OCT 18 2017

...HIGH SURF EXPECTED THURSDAY NIGHT THROUGH FRIDAY...

.A HUGE NORTHWEST SWELL AROUND 20 FEET WITH PERIODS NEAR
17 SECONDS WILL SPREAD INTO THE COASTAL WATERS THURSDAY NIGHT.
THE HUGE SWELL WILL PERSIST THROUGH THE DAY ON FRIDAY RESULTING
IN BREAKERS OF 23 TO 25 FEET IN THE SURF ZONE. THIS WILL POSE A
THREAT TO BEACH GOERS AND MARINERS TRAVERSING HARBOR ENTRANCES.

CAZ101-103-104-109-192200-
/O.CON.KEKA.SU.Y.0001.171020T0100Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
337 PM PDT WED OCT 18 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 6 PM THURSDAY TO
6 PM PDT FRIDAY...

* WAVES AND SURF...BREAKING WAVES 22 TO 25 FEET ALONG WEST AND 
  NORTHWEST FACING BEACHES. 

* IMPACTS...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 ESPECIALLY 
  DURING MAX EBB WHICH IS PREDICTED TO OCCUR AROUND 3:30 AM AND 
  4:00 PM FRIDAY...OR STAY IN PORT UNTIL THE THREAT SUBSIDES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

&&

$$
335 
WHUS46 KEKA 190223
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
723 PM PDT WED OCT 18 2017

...HIGH SURF EXPECTED THURSDAY NIGHT THROUGH FRIDAY...

.A LARGE NORTHWEST SWELL AROUND 20 FEET WITH A PERIOD NEAR 17 
SECONDS WILL SPREAD ACROSS THE COASTAL WATERS THURSDAY NIGHT INTO
FRIDAY. BREAKERS FROM 23 TO 25 FEET ARE EXPECTED IN THE SURF 
ZONE, AND WILL POSE A THREAT TO BEACH GOERS AND MARINERS 
TRAVERSING HARBOR ENTRANCES.

CAZ101-103-104-109-191400-
/O.CON.KEKA.SU.Y.0001.171020T0100Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
723 PM PDT WED OCT 18 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 6 PM THURSDAY TO
6 PM PDT FRIDAY...

* WAVES AND SURF...BREAKING WAVES 22 TO 25 FEET ALONG WEST AND 
  NORTHWEST FACING BEACHES. 

* IMPACTS...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...ESPECIALLY
  DURING MAX EBB WHICH IS PREDICTED TO OCCUR AROUND 3:30 AM AND
  4:00 PM FRIDAY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

&&

$$
799 
WHUS46 KEKA 190315
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
815 PM PDT WED OCT 18 2017

...HIGH SURF EXPECTED THURSDAY NIGHT THROUGH FRIDAY...

.A LARGE NORTHWEST SWELL AROUND 20 FEET WITH A PERIOD NEAR
17 SECONDS WILL SPREAD ACROSS THE COASTAL WATERS THURSDAY NIGHT
INTO FRIDAY. BREAKERS FROM 23 TO 25 FEET ARE EXPECTED IN THE SURF
ZONE, AND WILL POSE A THREAT TO BEACH GOERS AND MARINERS
TRAVERSING HARBOR ENTRANCES.

CAZ101-103-104-109-191400-
/O.EXT.KEKA.SU.Y.0001.171020T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
815 PM PDT WED OCT 18 2017

...HIGH SURF ADVISORY NOW IN EFFECT FROM 5 PM THURSDAY TO 6 PM
PDT FRIDAY...

* WAVES AND SURF...BREAKING WAVES 22 TO 25 FEET ALONG WEST AND 
  NORTHWEST FACING BEACHES. 

* IMPACTS...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...ESPECIALLY DURING MAX EBB WHICH IS PREDICTED TO OCCUR 
  AROUND 3:30 AM AND 4:00 PM FRIDAY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

&&

$$
720 
WHUS46 KEKA 191042
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
342 AM PDT THU OCT 19 2017

CAZ101-103-104-109-192330-
/O.CON.KEKA.SU.Y.0001.171020T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
342 AM PDT THU OCT 19 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON
TO 6 PM PDT FRIDAY...

* WAVES AND SURF...BREAKING WAVES 22 TO 25 FEET ALONG WEST AND 
  NORTHWEST FACING BEACHES. 

* IMPACTS...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... ESPECIALLY DURING MAX EBB WHICH IS PREDICTED TO OCCUR 
  AROUND 3:30 AM AND 4:00 PM FRIDAY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

&&

$$
186 
WHUS46 KEKA 192245
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
345 PM PDT THU OCT 19 2017

CAZ101-103-104-109-201100-
/O.CON.KEKA.SU.Y.0001.171020T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
345 PM PDT THU OCT 19 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM FRIDAY...

* WAVES AND SURF...BREAKING WAVES BUILDING TO 22 TO 25 FEET ALONG
  WEST AND NORTHWEST FACING BEACHES. 

* IMPACTS...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... ESPECIALLY
  DURING MAX EBB WHICH IS PREDICTED TO OCCUR AROUND 330 AM AND 
  400 PM FRIDAY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

$$
316 
WHUS46 KEKA 200305
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
805 PM PDT THU OCT 19 2017

CAZ101-103-104-109-201400-
/O.CON.KEKA.SU.Y.0001.000000T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
805 PM PDT THU OCT 19 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM PDT FRIDAY...

* WAVES AND SURF...BREAKING WAVES BUILDING TO 22 TO 25 FEET 
  ALONG WEST AND NORTHWEST FACING BEACHES. 

* IMPACTS...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... ESPECIALLY DURING MAX EBB WHICH IS PREDICTED TO OCCUR 
  AROUND 330 AM AND 400 PM FRIDAY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

$$
410 
WHUS46 KEKA 201016
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
316 AM PDT FRI OCT 20 2017


CAZ101-103-104-109-210100-
/O.CON.KEKA.SU.Y.0001.000000T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
316 AM PDT FRI OCT 20 2017

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM PDT THIS
EVENING...

* WAVES AND SURF...BREAKING WAVES TO 23 TO 25 FEET ALONG WEST AND
  NORTHWEST FACING BEACHES. 

* IMPACTS...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...ESPECIALLY DURING MAX EBB WHICH IS
  PREDICTED TO OCCUR AROUND 400 PM TODAY...OR STAY IN PORT.
  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF ADVISORY MEANS THAT HIGH SURF WILL AFFECT BEACHES IN
THE ADVISORY AREA, PRODUCING RIP CURRENTS AND LOCALIZED BEACH
EROSION.

$$
868 
WHUS46 KEKA 210047
CFWEKA

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
547 PM PDT FRI OCT 20 2017

CAZ101-103-104-109-210200-
/O.EXP.KEKA.SU.Y.0001.000000T0000Z-171021T0100Z/
COASTAL DEL NORTE-NORTHERN HUMBOLDT COAST-SOUTHWESTERN HUMBOLDT-
MENDOCINO COAST-
547 PM PDT FRI OCT 20 2017

...HIGH SURF ADVISORY WILL EXPIRE AT 6 PM PDT THIS EVENING...

* THIS IS THE FINAL STATEMENT FOR THIS EVENT.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 18, 2:37 PM PDTWind AdvisoryEKADel Norte, Humboldt26 hr
Oct 18, 3:18 PM PDTHazardous Seas WarningEKA51 hr

Nearby

High Surf Advisories in California, 2017Every high surf advisory in 2017

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.