Alert archive / California / Beach Hazards Statements in 2021

Beach Hazards Statement 9, NWS San Francisco Bay Area, CA

November 26, 20216 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Nov 26, 2021, 9:48 AM PST for 6 counties in California. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Nov 26, 2021, 9:48 AM PST (17:48 UTC)
Expired
Nov 26, 2021, 6:00 PM PST
In force
8 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 17:50 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, 5.8 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 2021-11-26Temperature 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 2021-11-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 square meters per square second.1939Sfc1 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
2209 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
-15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

361 
WHUS46 KMTR 261748
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
948 AM PST Fri Nov 26 2021

...LONG TO MODERATE PERIOD NORTHWEST SWELL RESULTING IN COASTAL
HAZARDS TO NORTHWEST FACING BEACHES UNTIL 6 PM PST THIS EVENING...

CAZ006-505-509-529-530-270200-
/O.NEW.KMTR.BH.S.0009.211126T1748Z-211127T0200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
948 AM PST Fri Nov 26 2021

...BEACH HAZARDS STATEMENT IN EFFECT UNTIL 6 PM PST THIS
EVENING...

* WHAT...Northwest to west swell 8 to 9 feet at 15 to 17 seconds.

* WHERE...San Francisco, Coastal North Bay Including Point Reyes 
  National Seashore, San Francisco Peninsula Coast, Northern 
  Monterey Bay and Southern Monterey Bay and Big Sur Coast.

* WHEN...Until 6 PM PST this evening.

* IMPACTS...Risk of sneaker waves and strong rip currents.

* ADDITIONAL DETAILS...Wave energy will lower below beach hazards
  criteria tonight and Saturday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazards Statement means the potential for dangerous
conditions exist due to sneaker waves and strong rip currents.
These waves can suddenly sweep unsuspecting people into the ocean
if too close to the ocean's edge, please stay well back from 
these dangerous conditions. Cold water shock is also a potential 
life threatening situation causing involuntary gasp reflexes which
can cause drowning. Due to strong rip currents it is also best to
remain out of the water to avoid hazardous swimming conditions.

&&

$$
1 follow-up statement
503 
WHUS46 KMTR 270134
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
534 PM PST Fri Nov 26 2021

CAZ006-505-509-529-530-270245-
/O.EXP.KMTR.BH.S.0009.000000T0000Z-211127T0200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
534 PM PST Fri Nov 26 2021

...BEACH HAZARDS STATEMENT WILL EXPIRE AT 6 PM PST THIS EVENING...

Longer period swell is still being observed south of Point Sur and
the Big Sur coast, but more widespread buoys are reporting 15
second swell or less. Therefore the Beach Hazard Statement is
being allowed to expire at 6 PM PST.

$$

Nearby

Beach Hazards Statements in California, 2021Every beach hazards statement in 2021

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.