Alert archive / California / Beach Hazards Statements in 2020

Beach Hazards Statement 10, NWS San Francisco Bay Area, CA

October 30, 20206 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Oct 30, 2020, 11:07 AM PDT for 6 counties in California. It took effect at Nov 1, 2020, 2:00 PM PST. It was in force for 27 hr.

The area

The counties it named.

The facts

Issued
Oct 30, 2020, 11:07 AM PDT (18:07 UTC)
In effect from
Nov 1, 2020, 2:00 PM PST
Expired
Nov 2, 2020, 5:00 PM PST
In force
27 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 18:06 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 12:00Z, 6.1 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 12:00Z on 2020-10-30Temperature 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 12:00Z on 2020-10-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
2476 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
30 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.

332 
WHUS46 KMTR 301807
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
1107 AM PDT Fri Oct 30 2020

...Sneaker waves and rip currents for northwest facing beaches 
from Coastal Sonoma County to Coastal Monterey County...

.A large northwest swell will arrive Sunday afternoon and impact 
the coastline through Monday afternoon before subsiding. Initial 
swell heights of 1 to 2 feet at 23 seconds is expected increasing
the risk of sneaker waves. By Sunday evening into Monday morning,
wave heights of 6 to 9 feet at periods of 18 to 20 seconds are 
expected, with most favored northwest facing beaches at 10 to 12 
feet.

CAZ006-505-509-530-310400-
/O.NEW.KMTR.BH.S.0010.201101T2200Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
1107 AM PDT Fri Oct 30 2020

...BEACH HAZARDS STATEMENT IN EFFECT FROM SUNDAY AFTERNOON
THROUGH MONDAY AFTERNOON...

The National Weather Service in San Francisco has issued a Beach
Hazards Statement for the risk of sneaker waves and rip currents,
which is in effect from Sunday afternoon through Monday 
afternoon.

* HAZARDS...Breaking waves from 6 to 9 feet, with beaches in most
  favored locations seeing breaks 10 to 12 feet with rip currents
  expected. With most beaches still fairly flat, extended run up 
  is expected making it dangerous for beachgoers.

* TIMING...From 3 PM PDT Sunday afternoon through 5 PM PST Monday
  afternoon.

* LOCATION...Coastline from Sonoma County south through Monterey
  county. In particular west to northwest facing beaches...including
  but not limited to...Ocean beach...Montara State Beach...Marina
  State Beach...Monastery Beach.

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker
  waves often catch people off guard and knock them into the
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Rip currents are typically more frequent and stronger in the 
vicinity of jetties...inlets...and piers. Swimmers caught in a rip
current should swim parallel to the coast to escape the rip 
current before trying to swim for shore. Large breaking waves can
lead to back and neck injuries. Swimmers should avoid swimming in
areas of large shore break and always swim near a lifeguard. Never
turn your back on the ocean!
&&

$$
7 follow-up statements
254 
WHUS46 KMTR 310403
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
903 PM PDT Fri Oct 30 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell will arrive Sunday afternoon
and impact the coastline through Monday afternoon before 
subsiding. Initial swell heights of 1 to 2 feet at 23 seconds is 
expected increasing the risk of sneaker waves. By Sunday evening 
into Monday morning, wave heights of 6 to 9 feet at periods of 18 
to 20 seconds are expected, with most favored northwest facing 
beaches at 10 to 12 feet.

CAZ006-505-509-530-311900-
/O.CON.KMTR.BH.S.0010.201101T2200Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
903 PM PDT Fri Oct 30 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM SUNDAY
AFTERNOON THROUGH MONDAY AFTERNOON...

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second
  periods, with beaches in most favored locations seeing breaks 
  10 to 12 feet with rip currents expected. With most beaches 
  still fairly flat, extended run up is expected making it 
  dangerous for beachgoers.

* TIMING...From 3 PM PDT Sunday afternoon through 5 PM PST 
  Monday afternoon.

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach.

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a rip
current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
420 
WHUS46 KMTR 311832
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
1132 AM PDT Sat Oct 31 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell will arrive Sunday afternoon
and impact the coastline through Monday afternoon before
subsiding. Initial swell heights of 1 to 2 feet at 23 seconds is
expected increasing the risk of sneaker waves. By Sunday evening
into Monday morning, wave heights of 6 to 9 feet at periods of
18 to 20 seconds are expected, with most favored northwest facing
beaches at 10 to 12 feet.

CAZ006-505-509-530-010400-
/O.CON.KMTR.BH.S.0010.201101T2200Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
1132 AM PDT Sat Oct 31 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM SUNDAY
AFTERNOON THROUGH MONDAY AFTERNOON...

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second 
  periods, with beaches in most favored locations seeing breaks 
  10 to 12 feet with rip currents expected. With most beaches 
  still fairly flat, extended run up is expected making it 
  dangerous for beachgoers. 

* TIMING...From 3 PM PDT Sunday afternoon through 5 PM PST 
  Monday afternoon. 

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach. 

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a
rip current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
570 
WHUS46 KMTR 010223
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
723 PM PDT Sat Oct 31 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell will arrive Sunday afternoon
and impact the coastline through Monday afternoon before
subsiding. Initial swell heights of 1 to 2 feet at 23 seconds is
expected increasing the risk of sneaker waves. By Sunday evening
into Monday morning, wave heights of 6 to 9 feet at periods of
18 to 20 seconds are expected, with most favored northwest facing
beaches at 10 to 12 feet.

CAZ006-505-509-530-011600-
/O.CON.KMTR.BH.S.0010.201101T2200Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
723 PM PDT Sat Oct 31 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM SUNDAY
AFTERNOON THROUGH MONDAY AFTERNOON...

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second 
  periods, with beaches in most favored locations seeing breaks 
  10 to 12 feet with rip currents expected. With most beaches 
  still fairly flat, extended run up is expected making it 
  dangerous for beachgoers. 

* TIMING...From 3 PM PDT Sunday afternoon through 5 PM PST 
  Monday afternoon. 

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach. 

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a
rip current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
444 
WHUS46 KMTR 011532
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
732 AM PST Sun Nov 1 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell will arrive Sunday afternoon
and impact the coastline through Monday afternoon before
subsiding. Initial swell heights of 1 to 2 feet at 23 seconds is
expected increasing the risk of sneaker waves. By Sunday evening
into Monday morning, wave heights of 6 to 9 feet at periods of
18 to 20 seconds are expected, with most favored northwest facing
beaches at 10 to 12 feet.

CAZ006-505-509-530-020500-
/O.CON.KMTR.BH.S.0010.201101T2200Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
732 AM PST Sun Nov 1 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 2 PM PST THIS
AFTERNOON THROUGH MONDAY AFTERNOON...

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second 
  periods, with beaches in most favored locations seeing breaks 
  10 to 12 feet with rip currents expected. With most beaches 
  still fairly flat, extended run up is expected making it 
  dangerous for beachgoers. 

* TIMING...From 3 PM PDT Sunday afternoon through 5 PM PST 
  Monday afternoon. 

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach. 

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a
rip current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
582 
WHUS46 KMTR 020407
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
807 PM PST Sun Nov 1 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell will arrive tonight and impact
the coastline through Monday afternoon before subsiding. Initial 
swell heights of 1 to 2 feet at 23 seconds is expected increasing 
the risk of sneaker waves. Tonight into Monday morning, wave heights
of 6 to 9 feet at periods of 18 to 20 seconds are expected, with 
most favored northwest facing beaches at 10 to 12 feet.

CAZ006-505-509-530-021600-
/O.CON.KMTR.BH.S.0010.000000T0000Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
807 PM PST Sun Nov 1 2020

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

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second 
  periods, with beaches in most favored locations seeing breaks 
  10 to 12 feet with rip currents expected. With most beaches 
  still fairly flat, extended run up is expected making it 
  dangerous for beachgoers. 

* TIMING...Through 5 PM PST Monday afternoon. 

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach. 

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a
rip current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
559 
WHUS46 KMTR 021540
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
740 AM PST Mon Nov 2 2020

...Sneaker waves and rip currents for northwest facing beaches
from Coastal Sonoma County to Coastal Monterey County...

.A large long period northwest swell is impacting the coastline 
through Monday afternoon before subsiding Monday night. Initial 
swell heights of 1 to 2 feet at 23 seconds is expected increasing 
the risk of sneaker waves. This morning through afternoon, wave 
heights of 6 to 9 feet at periods of 18 to 20 seconds are 
expected.

CAZ006-505-509-530-030100-
/O.CON.KMTR.BH.S.0010.000000T0000Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
740 AM PST Mon Nov 2 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 5 PM PST THIS
AFTERNOON...

* HAZARDS...Breaking waves from 6 to 9 feet with 18 to 20 second
  periods, with rip currents expected. With most beaches still 
  fairly flat, extended run up is expected making it dangerous for
  beachgoers. 

* TIMING...Through 5 PM PST Monday afternoon.

* LOCATION...Coastline from Sonoma County south through Monterey 
  county. In particular west to northwest facing beaches... 
  including but not limited to...Ocean beach...Montara State 
  Beach...Marina State Beach...Monastery Beach. 

* POTENTIAL IMPACTS...Increased risk of ocean drowning. Sneaker 
  waves often catch people off guard and knock them into the 
  ocean. Rip currents can pull swimmers and surfers out to sea. 
  Large breaking waves can cause injury, wash people off beaches 
  and rocks, and capsize small boats near shore. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement for rip currents means that conditions
are present to support a heightened risk of strong rip currents.
Rip currents are typically more frequent and stronger in the
vicinity of jetties...inlets...and piers. Swimmers caught in a
rip current should swim parallel to the coast to escape the rip
current before trying to swim for shore. Swimmers should always
swim near a lifeguard.

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.

Listen to NOAA Weather Radio or your local media for the latest
updates on this situation.

&&

$$
132 
WHUS46 KMTR 030053
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
453 PM PST Mon Nov 2 2020


CAZ006-505-509-530-030200-
/O.EXP.KMTR.BH.S.0010.000000T0000Z-201103T0100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-
Southern Monterey Bay and Big Sur Coast-
453 PM PST Mon Nov 2 2020

...BEACH HAZARDS STATEMENT WILL EXPIRE AT 5 PM PST THIS
AFTERNOON...

The beach hazards statement will be allowed to expire at 5 pm.

$$

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.