Alert archive / California / Beach Hazards Statements in 2018

Beach Hazards Statement 2, NWS San Francisco Bay Area, CA

April 12, 20186 counties in California

NWS San Francisco Bay Area, CA issued this beach hazards statement at Apr 12, 2018, 6:24 AM PDT for 6 counties in California. It took effect at Apr 13, 2018, 2:00 AM PDT. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued
Apr 12, 2018, 6:24 AM PDT (13:24 UTC)
In effect from
Apr 13, 2018, 2:00 AM PDT
Expired
Apr 13, 2018, 7:00 PM PDT
In force
17 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 13:25 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, 1.4 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 2018-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 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 2018-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.19395878Sfc1 km3 km6 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
1115 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
-41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

127 
WHUS46 KMTR 121324
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
624 AM PDT Thu Apr 12 2018

Northwesterly swell will increase tonight into tomorrow, peaking
Friday morning. Swell is expected to decrease Friday
afternoon/evening.

CAZ006-505-509-529-530-122130-
/O.NEW.KMTR.BH.S.0002.180413T0900Z-180414T0200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
624 AM PDT Thu Apr 12 2018

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

The National Weather Service in San Francisco has issued a Beach
Hazards Statement for rip currents, sneaker waves, and large shore
break, which is in effect from late tonight through Friday 
evening.

* WAVES AND SURF...Northwest swell 10 to 12 feet with a period of
  14 to 16 seconds. Breakers up to 20 feet possible.

* TIMING...Late tonight through 7 PM PDT Friday evening.

* LOCATION...West to northwest facing beaches along the Central 
  Coast from Sonoma County through Monterey County...including but
  not limited to...Ocean Beach, Montara State Beach, and Marina 
  State Beach.

* POTENTIAL IMPACTS...Impacts include rip currents, sneaker waves,
  and large shore break. Never turn your back to the ocean!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement means the potentially dangerous
conditions may exist on specific beaches. These hazards may
include large shore break...strong rip currents...and possibly 
sneaker waves. All of which could be life threatening. Be sure to 
always keep your eyes on the ocean.

&&

$$
2 follow-up statements
247 
WHUS46 KMTR 122114
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
214 PM PDT Thu Apr 12 2018

Northwesterly swell will increase tonight into tomorrow, peaking
Friday morning. Swell is expected to decrease Friday
afternoon/evening.

CAZ006-505-509-529-530-131000-
/O.CON.KMTR.BH.S.0002.180413T0900Z-180414T0200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
214 PM PDT Thu Apr 12 2018

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 2 AM PDT FRIDAY
THROUGH FRIDAY EVENING...

* WAVES AND SURF...Northwest swell 10 to 12 feet with a period 
  of 14 to 16 seconds. Breakers up to 20 feet possible. 

* TIMING...Late tonight through 7 PM PDT Friday evening.

* LOCATION...West to northwest facing beaches along the Central 
  Coast from Sonoma County through Monterey County...including 
  but not limited to...Ocean Beach, Montara State Beach, and 
  Marina State Beach. 

* POTENTIAL IMPACTS...Impacts include rip currents and large 
  shore break. Never turn your back to the ocean! 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement means the potentially dangerous
conditions may exist on specific beaches. These hazards may
include large shore break...strong rip currents. All of which 
could be life threatening. Be sure to always keep your eyes on the
ocean.

&&

$$
351 
WHUS46 KMTR 130810
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco Bay Area
110 AM PDT Fri Apr 13 2018

Northwesterly swell will increase this morning then decrease in
the afternoon and evening.

CAZ006-505-509-529-530-140200-
/O.CON.KMTR.BH.S.0002.180413T0900Z-180414T0200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
110 AM PDT Fri Apr 13 2018

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH THIS
EVENING...

* WAVES AND SURF...Northwest swell 10 to 12 feet with a period 
  of 14 to 16 seconds. Breakers up to 20 feet possible. 

* TIMING...Late tonight through 7 PM PDT this evening.

* LOCATION...West to northwest facing beaches along the Central 
  Coast from Sonoma County through Monterey County...including 
  but not limited to...Ocean Beach, Montara State Beach, and 
  Marina State Beach. 

* POTENTIAL IMPACTS...Impacts include rip currents and large 
  shore break. Never turn your back to the ocean! 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Beach Hazard Statement means the potentially dangerous
conditions may exist on specific beaches. These hazards may
include large shore break...strong rip currents. All of which
could be life threatening. Be sure to always keep your eyes on
the ocean.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 11, 6:47 PM PDTSpecial Weather StatementMTRSan Mateo28 min
Apr 12, 2:16 AM PDTSmall Craft AdvisoryMTR21 hr

Nearby

Beach Hazards Statements in California, 2018Every beach hazards statement in 2018

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.