Alert archive / California / Beach Hazards Statements in 2020

Beach Hazards Statement 5, NWS San Francisco Bay Area, CA

April 6, 20206 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Apr 6, 2020, 4:10 AM PDT for 6 counties in California. It took effect at Apr 7, 2020, 5:00 AM PDT. It was in force for 24 hr.

The area

The counties it named.

The facts

Issued
Apr 6, 2020, 4:10 AM PDT (11:10 UTC)
In effect from
Apr 7, 2020, 5:00 AM PDT
Expired
Apr 8, 2020, 5:00 AM PDT
In force
24 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 11:10 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, 11.2 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 2020-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 joules per kilogram.LCLLFCEL10008507005003002001001 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 2020-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
14 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
903 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

039 
WHUS46 KMTR 061110
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
410 AM PDT Mon Apr 6 2020

...Increasing risk of sneaker waves and strong rip currents from
Coastal Sonoma County to Coastal Monterey County 5 am Tuesday to 
5 am Wednesday...

.A long period southwest to west swell will impact the coastline
beginning early Tuesday morning and will continue into Wednesday
morning before subsiding. Energetic swell periods will reach 19 
to 20 seconds Tuesday morning then decrease to below 17 seconds by
Wednesday afternoon and evening.

CAZ006-505-509-529-530-070800-
/O.NEW.KMTR.BH.S.0005.200407T1200Z-200408T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
410 AM PDT Mon Apr 6 2020

...BEACH HAZARDS STATEMENT IN EFFECT FROM 5 AM PDT TUESDAY THROUGH
5 AM PDT WEDNESDAY...

* WHAT...Sneaker waves and strong rip currents.

* WHERE...Coastal Sonoma County to Coastal Monterey County.

* WHEN...5 AM PDT Tuesday to 5 AM PDT Wednesday.

* IMPACTS...Sneaker waves can knock unsuspecting beach goers over
  and into the sea. Rip currents can pull swimmers and surfers out
  to sea.

* ADDITIONAL DETAILS...Steep beaches will have a higher risk of
  sneaker wave and rip current activity with greater wave run-up
  onto beaches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Sneaker waves heighten the risk of unsuspecting beach goers being
swept into the sea by a wave. Rip currents are typically more 
frequent and stronger in the vicinity of jetties...inlets...and 
piers. People walking along the beach should never turn their back
to the sea. Fisherman should avoid fishing from rocks or jetties.
Remain out of the water to avoid hazardous swimming conditions. 
Anyone caught in a rip current should swim parallel to the coast 
to escape the rip current before trying to swim for shore.

&&

$$
4 follow-up statements
223 
WHUS46 KMTR 070732
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
1232 AM PDT Tue Apr 7 2020

...Increasing risk of sneaker waves and strong rip currents from
Coastal Sonoma County to Coastal Monterey County 5 am Tuesday to
5 am Wednesday...

.A long period southwest to west swell will impact the coastline
beginning early Tuesday morning and will continue into Wednesday
morning before subsiding. Energetic swell periods will reach
19 to 20 seconds Tuesday morning then decrease to below
17 seconds by Wednesday afternoon and evening.

CAZ006-505-509-529-530-072200-
/O.CON.KMTR.BH.S.0005.200407T1200Z-200408T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
1232 AM PDT Tue Apr 7 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 5 AM PDT EARLY
THIS MORNING THROUGH LATE TONIGHT...

* WHAT...Sneaker waves and strong rip currents.

* WHERE...Coastal Sonoma County to Coastal Monterey County.

* WHEN...5 AM PDT Tuesday to 5 AM PDT Wednesday.

* IMPACTS...Sneaker waves can knock unsuspecting beach goers 
  over and into the sea. Rip currents can pull swimmers and 
  surfers out to sea. 

* ADDITIONAL DETAILS...Steep beaches will have a higher risk of 
  sneaker wave and rip current activity with greater wave run-up 
  onto beaches. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Sneaker waves heighten the risk of unsuspecting beach goers being
swept into the sea by a wave. Rip currents are typically more
frequent and stronger in the vicinity of jetties...inlets...and
piers. People walking along the beach should never turn their
back to the sea. Fisherman should avoid fishing from rocks or
jetties. Remain out of the water to avoid hazardous swimming
conditions. Anyone caught in a rip current should swim parallel
to the coast to escape the rip current before trying to swim for
shore.

&&

$$
429 
WHUS46 KMTR 072129
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
229 PM PDT Tue Apr 7 2020

...Increasing risk of sneaker waves and strong rip currents from
Coastal Sonoma County to Coastal Monterey County until 5 AM 
Wednesday...

.A long period southwest to west swell will continue to impact 
the coastline into Wednesday morning before subsiding. Energetic 
swell periods of 18 to 20 seconds will persist into tonight and 
then decrease to below 17 seconds by Wednesday afternoon and 
evening.

CAZ006-505-509-529-530-080900-
/O.CON.KMTR.BH.S.0005.000000T0000Z-200408T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
229 PM PDT Tue Apr 7 2020

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

* WHAT...Sneaker waves and strong rip currents.

* WHERE...Coastal Sonoma County to Coastal Monterey County.

* WHEN...5 AM PDT Tuesday to 5 AM PDT Wednesday.

* IMPACTS...Sneaker waves can knock unsuspecting beach goers 
  over and into the sea. Rip currents can pull swimmers and 
  surfers out to sea. 

* ADDITIONAL DETAILS...Steep beaches will have a higher risk of 
  sneaker wave and rip current activity with greater wave run-up 
  onto beaches. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Sneaker waves heighten the risk of unsuspecting beach goers being
swept into the sea by a wave. Rip currents are typically more
frequent and stronger in the vicinity of jetties...inlets...and
piers. People walking along the beach should never turn their
back to the sea. Fisherman should avoid fishing from rocks or
jetties. Remain out of the water to avoid hazardous swimming
conditions. Anyone caught in a rip current should swim parallel
to the coast to escape the rip current before trying to swim for
shore.

&&

$$
520 
WHUS46 KMTR 080839
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
139 AM PDT Wed Apr 8 2020

...Increasing risk of sneaker waves and strong rip currents from
Coastal Sonoma County to Coastal Monterey County until 5 AM
Wednesday...

.A long period southwest to west swell will continue to impact
the coastline into Wednesday morning before subsiding. Energetic
swell periods of 18 to 20 seconds will persist into tonight and
then decrease to below 17 seconds by Wednesday afternoon and
evening.

CAZ006-505-509-529-530-081200-
/O.CON.KMTR.BH.S.0005.000000T0000Z-200408T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
139 AM PDT Wed Apr 8 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 5 AM PDT EARLY
THIS MORNING...

* WHAT...Sneaker waves and strong rip currents.

* WHERE...Coastal Sonoma County to Coastal Monterey County.

* WHEN...5 AM PDT Tuesday to 5 AM PDT Wednesday.

* IMPACTS...Sneaker waves can knock unsuspecting beach goers 
  over and into the sea. Rip currents can pull swimmers and 
  surfers out to sea. 

* ADDITIONAL DETAILS...Steep beaches will have a higher risk of 
  sneaker wave and rip current activity with greater wave run-up 
  onto beaches. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Sneaker waves heighten the risk of unsuspecting beach goers being
swept into the sea by a wave. Rip currents are typically more
frequent and stronger in the vicinity of jetties...inlets...and
piers. People walking along the beach should never turn their
back to the sea. Fisherman should avoid fishing from rocks or
jetties. Remain out of the water to avoid hazardous swimming
conditions. Anyone caught in a rip current should swim parallel
to the coast to escape the rip current before trying to swim for
shore.

&&

$$
123 
WHUS46 KMTR 081136
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
436 AM PDT Wed Apr 8 2020

CAZ006-505-509-529-530-081245-
/O.EXP.KMTR.BH.S.0005.000000T0000Z-200408T1200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
436 AM PDT Wed Apr 8 2020

...BEACH HAZARDS STATEMENT WILL EXPIRE AT 5 AM PDT EARLY THIS
MORNING...

The long period swell continues to slowly decrease below hazard
criteria, thereby allowing the advisory statement to expire.
Never turn your back to the ocean.

$$

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.