Alert archive / California / Beach Hazards Statements in 2019

Beach Hazards Statement 7, NWS San Francisco Bay Area, CA

November 21, 20196 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Nov 21, 2019, 1:37 PM PST for 6 counties in California. It took effect at Nov 22, 2019, 4:00 AM PST. It was in force for 36 hr.

The area

The counties it named.

The facts

Issued
Nov 21, 2019, 1:37 PM PST (21:37 UTC)
In effect from
Nov 22, 2019, 4:00 AM PST
Expired
Nov 23, 2019, 4:00 PM PST
In force
36 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 21:36 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, 9.6 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 12:00Z on 2019-11-21Temperature 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 2019-11-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
1517 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

235 
WHUS46 KMTR 212137
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
137 PM PST Thu Nov 21 2019

...INCREASED RISK OF SNEAKER WAVES LATE TONIGHT THROUGH LATE
FRIDAY NIGHT...

.A long period west-northwest swell will impact the coastline 
from Sonoma southward through Big Sur beginning late tonight. 
Forerunner waves will arrive late this evening but the greatest 
risk of sneaker waves impacting the coast will exist from late 
tonight through late Friday night. These sneaker waves will be 
infrequent waves powerful enough to knock unsuspecting people into
the ocean during otherwise deceptively light seas.

CAZ006-505-509-529-530-220700-
/O.NEW.KMTR.BH.S.0007.191122T1200Z-191123T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
137 PM PST Thu Nov 21 2019

...BEACH HAZARDS STATEMENT IN EFFECT FROM LATE TONIGHT THROUGH
LATE FRIDAY NIGHT...

The National Weather Service in San Francisco has issued a Beach
Hazards Statement for increased sneaker wave risk, which is in 
effect from late tonight through late Friday night. 

* HAZARDS...Increased sneaker wave risk.

* TIMING...From 4 AM Friday to 4 AM Saturday.

* LOCATION...Entire Pacific coastline from Sonoma south to Big 
  Sur.

* POTENTIAL IMPACTS...Larger surf at offshore breaks and an
  enhanced risk of sneaker waves on northwest California beaches.
  Steep beaches will have a higher risk of sneaker wave activity
  with greater wave run-up onto beaches. Large waves will also
  wash over jetties and rock outcroppings that may normally stay
  dry.

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.

&&

$$
5 follow-up statements
544 
WHUS46 KMTR 220414
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
814 PM PST Thu Nov 21 2019

...INCREASED RISK OF SNEAKER WAVES LATE TONIGHT THROUGH LATE
FRIDAY NIGHT...

.A long period west-northwest swell will impact the coastline
from Sonoma southward through Big Sur beginning late tonight.
Forerunner waves will arrive late this evening but the greatest
risk of sneaker waves impacting the coast will exist from late
tonight through late Friday night. These sneaker waves will be
infrequent waves powerful enough to knock unsuspecting people
into the ocean during otherwise deceptively light seas.

CAZ006-505-509-529-530-221800-
/O.CON.KMTR.BH.S.0007.191122T1200Z-191123T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
814 PM PST Thu Nov 21 2019

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 4 AM PST FRIDAY
THROUGH LATE FRIDAY NIGHT...

* HAZARDS...Increased sneaker wave risk.

* TIMING...From 4 AM Friday to 4 AM Saturday.

* LOCATION...Entire Pacific coastline from Sonoma south to Big 
  Sur. 

* POTENTIAL IMPACTS...Larger surf at offshore breaks and an 
  enhanced risk of sneaker waves on northwest California 
  beaches. Steep beaches will have a higher risk of sneaker wave 
  activity with greater wave run-up onto beaches. Large waves 
  will also wash over jetties and rock outcroppings that may 
  normally stay dry. 

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.

&&

$$
458 
WHUS46 KMTR 221559
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
759 AM PST Fri Nov 22 2019

...INCREASED RISK OF SNEAKER WAVES THROUGH LATE TONIGHT...

.There is a long period west-northwest swell which will impact 
the coastline from Sonoma southward through Big Sur. Forerunner 
waves will continue to impact the coast into early Saturday 
morning. These sneaker waves will be infrequent waves powerful 
enough to knock unsuspecting people into the ocean during 
otherwise deceptively light seas.

CAZ006-505-509-529-530-230000-
/O.CON.KMTR.BH.S.0007.000000T0000Z-191123T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
759 AM PST Fri Nov 22 2019

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH LATE
TONIGHT...

* HAZARDS...Increased sneaker wave risk.

* TIMING...Through 4 AM Saturday.

* LOCATION...Entire Pacific coastline from Sonoma south to Big 
  Sur. 

* POTENTIAL IMPACTS...Larger surf at offshore breaks and an 
  enhanced risk of sneaker waves on northwest California 
  beaches. Steep beaches will have a higher risk of sneaker wave 
  activity with greater wave run-up onto beaches. Large waves 
  will also wash over jetties and rock outcroppings that may 
  normally stay dry. 

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.

&&

$$
158 
WHUS46 KMTR 222246
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
246 PM PST Fri Nov 22 2019

...INCREASED RISK OF SNEAKER WAVES AND RIP CURRENTS THROUGH
SATURDAY AFTERNOON...

.Long period swells have arrived and will continue to impact area
beaches through Saturday afternoon. Nice weather and upcoming
holiday may draw more people than normal to area beaches this
weekend. Please use caution as sneaker waves and rip currents 
will be likely.

CAZ006-505-509-529-530-231400-
/O.EXT.KMTR.BH.S.0007.000000T0000Z-191124T0000Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
246 PM PST Fri Nov 22 2019

...BEACH HAZARDS STATEMENT NOW IN EFFECT THROUGH SATURDAY
AFTERNOON...

* HAZARDS...Increased sneaker wave and rip current risk.

* TIMING...Through 5 PM Saturday.

* LOCATION...Coastline from Sonoma south to Big Sur.
 
* POTENTIAL IMPACTS...Larger surf at offshore breaks and an
  enhanced risk of sneaker waves on area beaches. Steep beaches 
  will have a higher risk of sneaker wave activity with greater 
  wave run-up onto beaches. Large waves will also wash over 
  jetties and rock outcroppings that may normally stay dry. 

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.

&&

$$
371 
WHUS46 KMTR 231445
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
645 AM PST Sat Nov 23 2019

...INCREASED RISK OF SNEAKER WAVES AND RIP CURRENTS THROUGH
SATURDAY AFTERNOON...

.Long period swells have arrived and will continue to impact area
beaches through Saturday afternoon. Nice weather and upcoming
holiday may draw more people than normal to area beaches this
weekend. Please use caution as sneaker waves and rip currents
will be likely.

CAZ006-505-509-529-530-240000-
/O.CON.KMTR.BH.S.0007.000000T0000Z-191124T0000Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
645 AM PST Sat Nov 23 2019

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 4 PM PST THIS
AFTERNOON...

* HAZARDS...Increased sneaker wave and rip current risk.

* TIMING...Through 5 PM Saturday.

* LOCATION...Coastline from Sonoma south to Big Sur.

* POTENTIAL IMPACTS...Larger surf at offshore breaks and an 
  enhanced risk of sneaker waves on area beaches. Steep beaches 
  will have a higher risk of sneaker wave activity with greater 
  wave run-up onto beaches. Large waves will also wash over 
  jetties and rock outcroppings that may normally stay dry. 

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.

&&

$$
172 
WHUS46 KMTR 232355
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
355 PM PST Sat Nov 23 2019

CAZ006-505-509-529-530-240100-
/O.EXP.KMTR.BH.S.0007.000000T0000Z-191124T0000Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
355 PM PST Sat Nov 23 2019

...BEACH HAZARDS STATEMENT WILL EXPIRE AT 4 PM PST THIS
AFTERNOON...

The long period northwest swell which prompted the Beach Hazards
Statement has decreased, and the threat of sneaker waves and rip
currents have also decreased. However, waves at the beach will 
continue to be larger than normal and beachgoers should exercise 
caution near the water. Never turn your back to the ocean!

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 20, 9:21 PM PSTSmall Craft AdvisoryMTR6 hr
Nov 21, 2:39 PM PSTSmall Craft AdvisoryMTR24 hr

Nearby

Beach Hazards Statements in California, 2019Every beach hazards statement in 2019

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.