Alert archive / California / Beach Hazards Statements in 2020

Beach Hazards Statement 13, NWS San Francisco Bay Area, CA

December 6, 20206 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Dec 6, 2020, 3:38 AM PST for 6 counties in California. It took effect at Dec 7, 2020, 9:00 AM PST. It was in force for 22 hr.

The area

The counties it named.

The facts

Issued
Dec 6, 2020, 3:38 AM PST (11:38 UTC)
In effect from
Dec 7, 2020, 9:00 AM PST
Expired
Dec 8, 2020, 7:23 AM PST
In force
22 hr
Issued by
NWS San Francisco Bay Area, CA

Counties City and County of San Francisco, CA, Marin County, CA, Monterey County, CA, San Mateo County, CA, Santa Cruz County, CA, Sonoma County, CA

The radar

The San Francisco radar (KMUX), 53 km from the middle of the area, began a volume at 11:41 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, 11.6 hours before the alert went out and 26 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 2020-12-06Temperature 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 2020-12-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
2284 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

630 
WHUS46 KMTR 061138
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
338 AM PST Sun Dec 6 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST MONDAY THROUGH TUESDAY...

.A strong storm system near the Aleutians is forecast to generate
a very large, very long period northwest swell train that will 
arrive Monday before peaking Monday Night and Tuesday along the 
coast. For Monday, the primary hazard will be on the beaches 
where infrequent yet dangerous sneaker waves and stronger rip 
currents are expected. By Monday night, the swell heights are 
forecast to increase rapidly and the primary hazard will shift 
towards large breaking waves of roughly 25 feet at west and 
northwest facing beaches prompting dangerous conditions in the 
surf zone at west to northwest facing beaches. A beach hazard 
statement is in effect on Monday during the day for the sneaker 
wave threat while a high surf warning is in effect for Monday 
night through the day Tuesday for the large breaking waves
expected. Cold water drownings occur each year with these type of
events but are completely avoidable by remaining a safe distance
from the coastline. If you must visit the coastline, avoid 
venturing out on coastal rocks, outcroppings, jetties, etc, and 
remain extremely vigilant of your surroundings at all times.


CAZ006-505-509-530-062300-
/O.NEW.KMTR.SU.W.0001.201208T0100Z-201209T0100Z/
/O.NEW.KMTR.BH.S.0013.201207T1700Z-201208T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
338 AM PST Sun Dec 6 2020

...BEACH HAZARDS STATEMENT IN EFFECT FROM MONDAY MORNING THROUGH
MONDAY AFTERNOON...
...HIGH SURF WARNING IN EFFECT FROM 5 PM MONDAY TO 5 PM PST
TUESDAY...

* WHAT...For the Beach Hazards Statement, infrequent yet dangerous
  sneaker waves are expected on Monday. For the High Surf Warning,
  dangerously large breaking waves of 25 feet at west to northwest
  beaches Monday Night through Tuesday. Enhanced coastal run up,
  localized beach erosion, and stronger rip currents are expected
  both Monday and Tuesday. 

* WHERE...Main threat will be at west to northwest facings beaches
  along the entire coastline from Sonoma county southward through
  Big Sur in Monterey county. Excludes the Northern Monterey Bay
  (including Santa Cruz) due to this area being sheltered from the
  northwest seas.

* WHEN...For the Beach Hazards Statement, from Monday morning
  through Monday afternoon. For the High Surf Warning, from 5 PM 
  Monday to 5 PM PST Tuesday. 

* IMPACTS...Sneaker waves and large breaking waves can sweep
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and localized beach erosion can
  be expected. Cold water rescues or drownings are more likely
  with these waves and stronger rip currents.

* ADDITIONAL INFO...These types of events lead to cold water
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along the
beach should never turn their back to the sea. Fisherman should 
avoid fishing from rocks or jetties.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. 

A High Surf Warning for large breaking waves means conditions are
present to support large waves along the surf zone capable of 
sweeping people into the frigid and turbulent ocean water. Cold 
water shock may cause cardiac arrest, and it also can cause an 
involuntary gasp reflex causing drowning, even for a good swimmer.
The surf zone will be dangerous due to strong currents and 
powerful breaking waves. 


&&

$$
7 follow-up statements
150 
WHUS46 KMTR 062207
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
207 PM PST Sun Dec 6 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST MONDAY THROUGH TUESDAY...

.A strong storm system near the Aleutians is forecast to generate
a very large, very long period northwest swell train that will
arrive tomorrow before peaking tomorrow night and Tuesday along 
the coast. For tomorrow, the primary hazard will be on the 
beaches where infrequent yet dangerous sneaker waves and stronger 
rip currents are expected. By tomorrow night, the swell heights 
are forecast to increase rapidly and the primary hazard will shift
towards large breaking waves of roughly 25 feet at west and 
northwest facing beaches prompting dangerous conditions in the 
surf zone at west to northwest facing beaches. A beach hazard 
statement is in effect on Monday during the day for the sneaker 
wave threat while a high surf warning is in effect for Monday 
night through the day Tuesday for the large breaking waves 
expected. Cold water drownings occur each year with these type of 
events but are completely avoidable by remaining a safe distance 
from the coastline. If you must visit the coastline, avoid 
venturing out on coastal rocks, outcroppings, jetties, etc, and 
remain extremely vigilant of your surroundings at all times.

CAZ006-505-509-530-070700-
/O.CON.KMTR.SU.W.0001.201208T0100Z-201209T0100Z/
/O.CON.KMTR.BH.S.0013.201207T1700Z-201208T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
207 PM PST Sun Dec 6 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM MONDAY MORNING
THROUGH MONDAY AFTERNOON...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 5 PM MONDAY TO 5 PM
PST TUESDAY...

* WHAT...For the Beach Hazards Statement, infrequent yet dangerous
  sneaker waves are expected tomorrow. For the High Surf Warning,
  dangerously large breaking waves of 25 feet at west to northwest
  beaches tomorrow night through Tuesday. Enhanced coastal run 
  up, localized beach erosion, and stronger rip currents are 
  expected both Monday and Tuesday. 

* WHERE...Main threat will be at west to northwest facings beaches
  along the entire coastline from Sonoma county southward through
  Big Sur in Monterey county. Excludes the Northern Monterey Bay
  (including Santa Cruz) due to this area being sheltered from the
  northwest seas.

* WHEN...For the Beach Hazards Statement, from Monday morning
  through Monday afternoon. For the High Surf Warning, from 5 PM
  Monday to 5 PM PST Tuesday.

* IMPACTS...Sneaker waves and large breaking waves can sweep
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and localized beach erosion can
  be expected. Cold water rescues or drownings are more likely
  with these waves and stronger rip currents.

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along the
beach should never turn their back to the sea. Fisherman should 
avoid fishing from rocks or jetties.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. 

A High Surf Warning for large breaking waves means conditions are
present to support large waves along the surf zone capable of 
sweeping people into the frigid and turbulent ocean water. Cold 
water shock may cause cardiac arrest, and it also can cause an 
involuntary gasp reflex causing drowning, even for a good swimmer.
The surf zone will be dangerous due to strong currents and 
powerful breaking waves. 

&&

$$
751 
WHUS46 KMTR 070458
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
858 PM PST Sun Dec 6 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST MONDAY THROUGH TUESDAY...

.A very large, very long period northwest swell train that will 
arrive Monday before peaking tomorrow night and Tuesday along the
coast. For tomorrow, the primary hazard will be on the beaches 
where infrequent yet dangerous sneaker waves and stronger rip 
currents are expected. By tomorrow night, the swell heights are 
forecast to increase rapidly and the primary hazard will shift 
towards large breaking waves of roughly 25 feet at west and 
northwest facing beaches prompting dangerous conditions in the 
surf zone at west to northwest facing beaches. A beach hazard 
statement is in effect on Monday during the day for the sneaker 
wave threat while a high surf warning is in effect for Monday 
night through the day Tuesday for the large breaking waves 
expected. Cold water drownings occur each year with these type of 
events but are completely avoidable by remaining a safe distance 
from the coastline. If you must visit the coastline, avoid 
venturing out on coastal rocks, outcroppings, jetties, etc, and 
remain extremely vigilant of your surroundings at all times.

CAZ006-505-509-530-071300-
/O.CON.KMTR.SU.W.0001.201208T0100Z-201209T0100Z/
/O.CON.KMTR.BH.S.0013.201207T1700Z-201208T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
858 PM PST Sun Dec 6 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM MONDAY MORNING
THROUGH MONDAY AFTERNOON...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 5 PM MONDAY TO 5 PM
PST TUESDAY...

* WHAT...For the Beach Hazards Statement, infrequent yet 
  dangerous sneaker waves are expected tomorrow. For the High 
  Surf Warning, dangerously large breaking waves of 25 feet at 
  west to northwest beaches tomorrow night through Tuesday. 
  Enhanced coastal run up, localized beach erosion, and stronger 
  rip currents are expected both Monday and Tuesday. 

* WHERE...Main threat will be at west to northwest facings 
  beaches along the entire coastline from Sonoma county 
  southward through Big Sur in Monterey county. Excludes the 
  Northern Monterey Bay (including Santa Cruz) due to this area 
  being sheltered from the northwest seas. 

* WHEN...For the Beach Hazards Statement, from Monday morning 
  through Monday afternoon. For the High Surf Warning, from 5 PM 
  Monday to 5 PM PST Tuesday. 

* IMPACTS...Sneaker waves and large breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and localized beach erosion 
  can be expected. Cold water rescues or drownings are more 
  likely with these waves and stronger rip currents. 

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties.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.

A High Surf Warning for large breaking waves means conditions are
present to support large waves along the surf zone capable of
sweeping people into the frigid and turbulent ocean water. Cold
water shock may cause cardiac arrest, and it also can cause an
involuntary gasp reflex causing drowning, even for a good
swimmer. The surf zone will be dangerous due to strong currents
and powerful breaking waves.

&&

$$
603 
WHUS46 KMTR 071046
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
246 AM PST Mon Dec 7 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST THROUGH TUESDAY...

.A very large, very long period northwest swell train will arrive
today and peak from tonight through Tuesday along the coast. For 
tomorrow, the primary hazard will be infrequent yet dangerous 
sneaker waves and stronger rip currents. By tonight, the swell 
heights are forecast to increase rapidly and the primary hazard 
will shift towards large breaking waves of roughly 25 feet at west
and northwest facing beaches. A beach hazard statement is in 
effect during the day today for the sneaker wave threat while a 
high surf warning is in effect for Monday night through the day 
Tuesday for the large breaking waves. Cold water drownings occur 
each year with these type of events but are completely avoidable 
by remaining a safe distance from the coastline. If you must visit
the coastline, avoid venturing out on coastal rocks, 
outcroppings, jetties, etc, and remain extremely vigilant of your 
surroundings at all times.

CAZ006-505-509-530-072315-
/O.CON.KMTR.SU.W.0001.201208T0100Z-201209T0100Z/
/O.CON.KMTR.BH.S.0013.201207T1700Z-201208T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
246 AM PST Mon Dec 7 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 9 AM PST THIS
MORNING THROUGH THIS AFTERNOON...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON
TO 5 PM PST TUESDAY...

* WHAT...For the Beach Hazards Statement, infrequent yet 
  dangerous sneaker waves are expected tomorrow. For the High 
  Surf Warning, dangerously large breaking waves of 25 feet at 
  west to northwest beaches tomorrow night through Tuesday. 
  Enhanced coastal run up, localized beach erosion, and stronger 
  rip currents are expected both Monday and Tuesday. 

* WHERE...Main threat will be at west to northwest facings 
  beaches along the entire coastline from Sonoma county 
  southward through Big Sur in Monterey county. Excludes the 
  Northern Monterey Bay (including Santa Cruz) due to this area 
  being sheltered from the northwest seas. 

* WHEN...For the Beach Hazards Statement, from this morning
  through 5 PM PST this afternoon. For the High Surf Warning, 
  from 5 PM Monday to 5 PM PST Tuesday. 

* IMPACTS...Sneaker waves and large breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and localized beach erosion 
  can be expected. Cold water rescues or drownings are more 
  likely with these waves and stronger rip currents. 

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties.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.

A High Surf Warning for large breaking waves means conditions are
present to support large waves along the surf zone capable of
sweeping people into the frigid and turbulent ocean water. Cold
water shock may cause cardiac arrest, and it also can cause an
involuntary gasp reflex causing drowning, even for a good
swimmer. The surf zone will be dangerous due to strong currents
and powerful breaking waves.

&&

$$
071 
WHUS46 KMTR 071638
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
838 AM PST Mon Dec 7 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST THROUGH TUESDAY...

.A very large, very long period northwest swell train will arrive
today and peak from tonight through Tuesday along the coast. For
today, the primary hazard will be infrequent yet dangerous 
sneaker waves and stronger rip currents. By tonight, the swell 
heights are forecast to increase rapidly and the primary hazard 
will shift towards large breaking waves of roughly 25 feet at west
and northwest facing beaches. A Beach Hazard Statement is in 
effect during the day today for the sneaker wave threat while a 
High Surf Warning is in effect for Monday night through the day 
Tuesday for the large breaking waves. Cold water drownings occur 
each year with these type of events but are completely avoidable 
by remaining a safe distance from the coastline. If you must visit
the coastline, avoid venturing out on coastal rocks, 
outcroppings, jetties, etc, and remain extremely vigilant of your 
surroundings at all times.

CAZ006-505-509-530-080100-
/O.CON.KMTR.SU.W.0001.201208T0100Z-201209T0100Z/
/O.CON.KMTR.BH.S.0013.201207T1700Z-201208T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
838 AM PST Mon Dec 7 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 5 PM PST THIS
AFTERNOON...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON
TO 5 PM PST TUESDAY...

* WHAT...For the Beach Hazards Statement, infrequent yet dangerous
  sneaker waves are expected today. For the High Surf Warning,
  dangerously large breaking waves of 25 feet at west to northwest
  beaches tonight through Tuesday. Enhanced coastal run up,
  localized beach erosion, and stronger rip currents are expected
  both today and Tuesday. 

* WHERE...Main threat will be at west to northwest facings beaches
  along the entire coastline from Sonoma county southward through
  Big Sur in Monterey county. The Northern Monterey Bay (including
  Santa Cruz) will face a lesser threat due to this area being
  sheltered from northwest seas, however, there will still be an
  increased risk of sneaker waves, rip currents, and larger wave
  runup. 

* WHEN...For the Beach Hazards Statement, from this morning
  through 5 PM PST this afternoon (For the Northern Monterey Bay 
  will run through 5 PM PST Tuesday). For the High Surf Warning, 
  from 5 PM Monday to 5 PM PST Tuesday. 

* IMPACTS...Sneaker waves and large breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and localized beach erosion 
  can be expected. Cold water rescues or drownings are more 
  likely with these waves and stronger rip currents. 

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties. 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.

A High Surf Warning for large breaking waves means conditions are
present to support large waves along the surf zone capable of
sweeping people into the frigid and turbulent ocean water. Cold
water shock may cause cardiac arrest, and it also can cause an
involuntary gasp reflex causing drowning, even for a good
swimmer. The surf zone will be dangerous due to strong currents
and powerful breaking waves.

&&

$$

CAZ529-080100-
/O.EXB.KMTR.BH.S.0013.201207T1700Z-201209T0100Z/
Northern Monterey Bay-
838 AM PST Mon Dec 7 2020

...BEACH HAZARDS STATEMENT IN EFFECT THROUGH TUESDAY AFTERNOON...

* WHAT...Infrequent yet dangerous sneaker waves are expected with
  an increased risk of strong rip currents, increased wave runup,
  and occasionally large breaking waves.

* WHERE...Northern Monterey Bay (including Santa Cruz).

* WHEN...Through 5 PM PST Tuesday afternoon.

* IMPACTS...Sneaker waves and large breaking waves can sweep
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions can be expected. Cold water 
  rescues or drownings are more likely with these waves and 
  stronger rip currents.

* ADDITIONAL INFO...Though typically more sheltered from northwest
  swell trains, the large nature of the upcoming swell will still
  increase the risk of dangerous sneaker waves and rip currents
  throughout the event. These types of events lead to cold water 
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties. 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.

&&

$$
091 
WHUS46 KMTR 080127
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
527 PM PST Mon Dec 7 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST THROUGH TUESDAY...

The expected very large, very long period northwest swell train 
has arrived and will peak from tonight through Tuesday along the 
coast. Swell heights are forecast to increase rapidly, and the 
primary hazard will be large breaking waves of roughly 25 feet at 
west and northwest facing beaches. A High Surf Warning is in 
effect tonight through the day Tuesday for the large breaking 
waves. For Northern Monterey Bay (including Santa Cruz), a Beach 
Hazard Statement remains in effect through Tuesday afternoon. 
Though typically more sheltered from northwest swell trains, the 
large nature of the upcoming swell will still increase the risk of
dangerous sneaker waves and rip currents throughout the 
event. Cold water drownings occur each year with these type of 
events but are completely avoidable by remaining a safe distance 
from the coastline. If you must visit the coastline, avoid 
venturing out on coastal rocks, outcroppings, jetties, etc, and 
remain extremely vigilant of your surroundings at all times.

CAZ006-505-509-530-081200-
/O.EXP.KMTR.BH.S.0013.000000T0000Z-201208T0100Z/
/O.CON.KMTR.SU.W.0001.000000T0000Z-201209T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
527 PM PST Mon Dec 7 2020

...HIGH SURF WARNING IS NOW IN EFFECT UNTIL 5 PM PST TUESDAY...

* WHAT...Dangerously large breaking waves of 25 feet at west to 
  northwest beaches tonight through Tuesday. Enhanced coastal run 
  up, localized beach erosion, and stronger rip currents are 
  expected both today and Tuesday. 

* WHERE...Main threat will be at west to northwest facings 
  beaches along the entire coastline from Sonoma county 
  southward through Big Sur in Monterey county. The Northern 
  Monterey Bay (including Santa Cruz) will face a lesser threat 
  due to this area being sheltered from northwest seas, however, 
  there will still be an increased risk of sneaker waves, rip 
  currents, and larger wave runup.

* WHEN...For the Beach Hazards Statement, from this morning 
  through 5 PM PST this afternoon (For the Northern Monterey Bay 
  will run through 5 PM PST Tuesday). For the High Surf Warning, 
  from 5 PM Monday to 5 PM PST Tuesday.

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

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ529-081200-
/O.CON.KMTR.BH.S.0013.000000T0000Z-201209T0100Z/
Northern Monterey Bay-
527 PM PST Mon Dec 7 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH TUESDAY
AFTERNOON...

* WHAT...Infrequent yet dangerous sneaker waves are expected 
  with an increased risk of strong rip currents, increased wave 
  runup, and occasionally large breaking waves.

* WHERE...Northern Monterey Bay (including Santa Cruz).

* WHEN...Through 5 PM PST Tuesday afternoon.

* IMPACTS...Sneaker waves and large breaking waves can sweep
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions can be expected. Cold water
  rescues or drownings are more likely with these waves and
  stronger rip currents.

* ADDITIONAL INFO...Though typically more sheltered from 
  northwest swell trains, the large nature of the upcoming swell 
  will still increase the risk of dangerous sneaker waves and 
  rip currents throughout the event. These types of events lead 
  to cold water drownings each year so extreme vigilance is 
  advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties. 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.

&&

$$
030 
WHUS46 KMTR 081143
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
343 AM PST Tue Dec 8 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS 
CONDITIONS ALONG THE COAST TODAY...

A very large, long period northwest swell train will peak through
this morning along the coast. The primary hazard will be large 
breaking waves of roughly 25 feet at west and northwest facing 
beaches. A High Surf Warning is in effect until 5 PM PST today for
the large breaking waves. For the Northern Monterey Bay including
Santa Cruz, a Beach Hazard Statement remains in effect until 5 PM
PST today. Though typically more sheltered from northwest swell 
trains, the large nature of the swell will increase the risk of 
dangerous sneaker waves and rip currents. Cold water drownings 
occur each year with these type of events but are completely 
avoidable by remaining a safe distance from the coastline. If you 
must visit the coastline, avoid venturing out on coastal rocks, 
outcroppings, jetties, etc, and remain extremely vigilant of your 
surroundings at all times.

CAZ006-505-509-530-082200-
/O.CON.KMTR.SU.W.0001.000000T0000Z-201209T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
343 AM PST Tue Dec 8 2020

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 5 PM PST THIS
AFTERNOON...

* WHAT...Dangerously large breaking waves of 25 feet at west to
  northwest beaches until 5 PM PST today. Enhanced coastal run up,
  localized beach erosion, and stronger rip currents are expected
  today. 

* WHERE...Main threat will be at west to northwest facings beaches
  along the entire coastline from Sonoma county southward through
  Big Sur in Monterey county. The Northern Monterey Bay including
  Santa Cruz will face a lesser threat due sheltering from  
  northwest seas, however, there will still be an increased risk 
  of sneaker waves, rip currents, and larger wave runup. 

* WHEN...The High Surf Warning is in effect until 5 PM PST today. 

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

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ529-082200-
/O.CON.KMTR.BH.S.0013.000000T0000Z-201209T0100Z/
Northern Monterey Bay-
343 AM PST Tue Dec 8 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH THIS
AFTERNOON...

* WHAT...Infrequent yet dangerous sneaker waves are expected 
  with an increased risk of strong rip currents, increased wave 
  runup, and occasionally large breaking waves. 

* WHERE...Northern Monterey Bay including Santa Cruz.

* WHEN...The Beach Hazards Statement is in effect until 5 PM PST 
  today.

* IMPACTS...Sneaker waves and large breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions can be expected. Cold water 
  rescues or drownings are more likely with these waves and 
  stronger rip currents. 

* ADDITIONAL INFO...Though typically more sheltered from 
  northwest swell trains, the large nature of the upcoming swell 
  will still increase the risk of dangerous sneaker waves and 
  rip currents throughout the event. These types of events lead 
  to cold water drownings each year so extreme vigilance is 
  advised. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for sneaker waves means that conditions
are present to support a heightened risk of unsuspecting beach
goers being swept into the sea by a wave. People walking along
the beach should never turn their back to the sea. Fisherman
should avoid fishing from rocks or jetties. 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.

&&

$$
783 
WHUS46 KMTR 081523
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
723 AM PST Tue Dec 8 2020

...VERY LARGE, LONG PERIOD NORTHWEST SWELL WILL BRING HAZARDOUS
CONDITIONS ALONG THE COAST THROUGH THE EVENING...

A very large, long period northwest swell train will peak through
this morning along the coast. The primary hazard will be large
breaking waves of roughly 25 feet at west and northwest facing
beaches, locally higher at favored break points. A High Surf 
Warning is in effect until 9 PM PST today for the large breaking 
waves. For the Northern Monterey Bay including Santa Cruz, the
Beach Hazard Statement has been upgraded to a High Surf Advisory 
until 9 PM PST today. Though typically more sheltered from 
northwest swell trains, the large nature of the swell will 
increase the risk of dangerous sneaker waves and rip currents as
well as bring large breaking waves into the surf zone. Cold water
drownings occur each year with these type of events but are 
completely avoidable by remaining a safe distance from the 
coastline. If you must visit the coastline, avoid venturing out on
coastal rocks, outcroppings, jetties, etc, and remain extremely 
vigilant of your surroundings at all times.

CAZ529-090100-
/O.CAN.KMTR.BH.S.0013.000000T0000Z-201209T0100Z/
/O.NEW.KMTR.SU.Y.0006.201208T1600Z-201209T0500Z/
Northern Monterey Bay-
723 AM PST Tue Dec 8 2020

...HIGH SURF ADVISORY IN EFFECT UNTIL 9 PM PST THIS EVENING...
...BEACH HAZARDS STATEMENT IS CANCELED...

* WHAT...Infrequent yet dangerous sneaker waves are expected with
  an increased risk of strong rip currents, increased wave runup,
  and large breaking waves. 

* WHERE...Northern Monterey Bay County including Santa Cruz.

* WHEN...Until 9 PM PST this evening.

* IMPACTS...Sneaker waves and large breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions can be expected. Cold water 
  rescues or drownings are more likely with these waves and 
  stronger rip currents. 

* ADDITIONAL INFO...Though typically more sheltered from northwest
  swell trains, the large nature of the upcoming swell will still
  increase the risk of dangerous sneaker waves and rip currents
  throughout the event. Large breaking waves are also expected. These
  types of events lead to cold water drownings each year so 
  extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A High Surf Advisory means that high surf will affect beaches in
the advisory area, producing rip currents, localized beach erosion
and sneaker waves. People walking along the beach should never 
turn their back to the sea. Fisherman should avoid fishing from 
rocks or jetties. 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.

&&

$$

CAZ006-505-509-530-090100-
/O.EXT.KMTR.SU.W.0001.000000T0000Z-201209T0500Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
723 AM PST Tue Dec 8 2020

...HIGH SURF WARNING NOW IN EFFECT UNTIL 9 PM PST THIS EVENING...

* WHAT...Dangerously large breaking waves of 25 feet at west to
  northwest beaches, locally higher at favored breakpoints. 
  Enhanced coastal run up, localized beach erosion, and stronger 
  rip currents are expected today. 

* WHERE...Main threat will be at west to northwest facings beaches
  along the entire coastline from Sonoma county southward through
  Big Sur in Monterey county. The Northern Monterey Bay including
  Santa Cruz will face a lesser threat due sheltering from
  northwest seas, however, there will still be an increased risk
  of sneaker waves, rip currents, large breaking waves and larger
  wave runup.
 
* WHEN...Until 9 PM PST this evening.

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

* ADDITIONAL INFO...These types of events lead to cold water 
  drownings each year so extreme vigilance is advised.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 6, 2:26 AM PSTSmall Craft AdvisoryMTR6 days
Dec 6, 2:57 AM PSTGale WarningMTR32 hr
Dec 6, 3:05 AM PSTWind AdvisoryMTRAlameda, Contra Costa, Marin, Napa, City and County of San Francisco, San Mateo and 3 more32 hr
Dec 6, 3:18 AM PSTRed Flag WarningMTRAlameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara and 2 more38 hr
Dec 6, 3:38 AM PSTHigh Surf WarningMTRMarin, Monterey, City and County of San Francisco, San Mateo, Santa Cruz, Sonoma65 hr

Nearby

Beach Hazards Statements in California, 2020Every beach hazards statement in 2020

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.