Alert archive / California / Beach Hazards Statements in 2020

Beach Hazards Statement 1, NWS San Francisco Bay Area, CA

January 20, 20206 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Jan 20, 2020, 8:52 AM PST for 6 counties in California. It took effect at Jan 20, 2020, 3:00 PM PST. It was in force for 34 hr.

The area

The counties it named.

The facts

Issued
Jan 20, 2020, 8:52 AM PST (16:52 UTC)
In effect from
Jan 20, 2020, 3:00 PM PST
Expired
Jan 22, 2020, 1:27 AM PST
In force
34 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 16:49 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, 4.9 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 2020-01-20Temperature 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 2020-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1937 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
166 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

488 
WHUS46 KMTR 201652
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
852 AM PST Mon Jan 20 2020

CAZ006-505-509-529-530-210500-
/O.NEW.KMTR.BH.S.0001.200120T2300Z-200121T2300Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
852 AM PST Mon Jan 20 2020

...BEACH HAZARDS STATEMENT IN EFFECT FROM 3 PM PST THIS AFTERNOON
THROUGH TUESDAY AFTERNOON...

The National Weather Service in San Francisco has issued a Beach
Hazards Statement for an increased threat of sneaker waves and rip
currents, which is in effect from 3 PM PST this afternoon through
Tuesday afternoon.


* WHAT...A long period northwesterly swell will bring large
  breaking waves and an increased threat of sneaker waves and rip
  currents to area beaches.

* WHERE...Coastline from Sonoma County southward through Monterey
  County.

* WHEN...From 3 PM PST this afternoon through Tuesday afternoon.

* IMPACTS...Large breaking waves will generate hazardous
  conditions on area beaches. This threat will be maximized on
  steeply sloped beaches. 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.

* ADDITIONAL DETAILS...There is a chance that a High Surf 
  Advisory will be issued for Tuesday into Tuesday night as the 
  northwesterly swell builds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain out of the water due to dangerous surf conditions, or stay
near occupied lifeguard towers. Rock jetties can be deadly in
such conditions, stay off the rocks.

&&

$$
4 follow-up statements
539 
WHUS46 KMTR 210405
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
805 PM PST Mon Jan 20 2020

CAZ006-505-509-529-530-212300-
/O.CON.KMTR.BH.S.0001.000000T0000Z-200121T2300Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
805 PM PST Mon Jan 20 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH 3 PM PST TUESDAY
AFTERNOON...

* WHAT...A long period northwesterly swell will bring large 
  breaking waves and an increased threat of sneaker waves and 
  rip currents to area beaches. 

* WHERE...Coastline from Sonoma County southward through 
  Monterey County. 

* WHEN...Through 3 pm Tuesday afternoon.

* IMPACTS...Large breaking waves will generate hazardous 
  conditions on area beaches. This threat will be maximized on 
  steeply sloped beaches. 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. 

* ADDITIONAL DETAILS...There is a chance that a High Surf 
  Advisory will be issued for Tuesday into Tuesday night as the 
  northwesterly swell builds. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain out of the water due to dangerous surf conditions, or stay
near occupied lifeguard towers. Rock jetties can be deadly in
such conditions, stay off the rocks.

&&

$$
939 
WHUS46 KMTR 211554
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
754 AM PST Tue Jan 21 2020

CAZ006-505-509-529-530-212300-
/O.CON.KMTR.BH.S.0001.000000T0000Z-200121T2300Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
754 AM PST Tue Jan 21 2020

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 3 PM PST THIS
AFTERNOON...

* WHAT...A long period northwesterly swell will bring large 
  breaking waves and an increased threat of sneaker waves and 
  rip currents to area beaches.

* WHERE...Coastline from Sonoma County southward through 
  Monterey County.

* WHEN...Through 3 PM PST this afternoon.

* IMPACTS...Large breaking waves will generate hazardous
  conditions on area beaches. This threat will be maximized on
  steeply sloped beaches. 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...

Remain out of the water due to dangerous surf conditions, or stay
near occupied lifeguard towers. Rock jetties can be deadly in
such conditions, stay off the rocks.

If caught in a rip current, relax and float. Don't swim against 
the current. If able, swim in a direction following the shoreline.
If unable to escape, face the shore and call or wave for help.

&&

$$
530 
WHUS46 KMTR 212208
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
208 PM PST Tue Jan 21 2020

CAZ006-505-509-529-530-221100-
/O.EXT.KMTR.BH.S.0001.000000T0000Z-200122T1700Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
208 PM PST Tue Jan 21 2020

...BEACH HAZARDS STATEMENT NOW IN EFFECT THROUGH WEDNESDAY
MORNING...

* WHAT...A long period northwesterly swell will continue to
  produce large breaking waves and an increased threat of sneaker
  waves and rip currents to area beaches.

* WHERE...Coastline from Sonoma County southward through 
  Monterey County.

* WHEN...Through Wednesday morning.

* IMPACTS...Large breaking waves will generate hazardous 
  conditions on area beaches. This threat will be maximized on 
  steeply sloped beaches. 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...

Remain out of the water due to dangerous surf conditions, or stay
near occupied lifeguard towers. Rock jetties can be deadly in
such conditions, stay off the rocks.

If caught in a rip current, relax and float. Don't swim against
the current. If able, swim in a direction following the
shoreline. If unable to escape, face the shore and call or wave
for help.

&&

$$
194 
WHUS46 KMTR 220927
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
127 AM PST Wed Jan 22 2020

CAZ006-505-509-529-530-221030-
/O.CAN.KMTR.BH.S.0001.000000T0000Z-200122T1700Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
127 AM PST Wed Jan 22 2020

...BEACH HAZARDS STATEMENT IS CANCELLED...

Buoy observations indicate wave energy has fallen below criteria
for a beach hazard statement. Occasional larger waves may still 
be present with this wave set into the sunrise hours. 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 20, 8:28 AM PSTSmall Craft AdvisoryMTR55 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.