Alert archive / California / Beach Hazards Statements in 2020
Beach Hazards Statement 9, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this beach hazards statement at Sep 24, 2020, 7:40 AM PDT for 6 counties in California. It took effect at Sep 24, 2020, 5:00 PM PDT. It was in force for 27 hr.
The area
The counties it named.
The facts
- Issued
- Sep 24, 2020, 7:40 AM PDT (14:40 UTC)
- In effect from
- Sep 24, 2020, 5:00 PM PDT
- Expired
- Sep 25, 2020, 8:00 PM PDT
- In force
- 27 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 14:46 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, 2.7 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 543 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -47 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
509 WHUS46 KMTR 241440 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 740 AM PDT Thu Sep 24 2020 ...Large breaking waves and increased risk of dangerous rip currents for west to northwest facing beaches from Coastal Sonoma County to Coastal Monterey County... .The first true northwest swell of the season will arrive this afternoon and impact the coastline through Friday afternoon before subsiding. Swell heights of 10 to 12 feet at periods of 15 to 16 seconds are expected. CAZ006-505-509-530-250400- /O.NEW.KMTR.BH.S.0009.200925T0000Z-200925T2100Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast- Southern Monterey Bay and Big Sur Coast- 740 AM PDT Thu Sep 24 2020 ...BEACH HAZARDS STATEMENT IN EFFECT FROM 5 PM PDT THIS AFTERNOON THROUGH FRIDAY AFTERNOON... * WHAT...Large breaking waves of 15 to 20 feet with dangerous rip currents expected. Steep beaches may experience breaking waves in excess of 20 feet. * WHERE...Coastline from Sonoma County southward through Monterey County. In particular west to northwest facing beaches... including but not limited to...Ocean Beach, Montara State Beach, and Marina State Beach. * WHEN...From 5 PM PDT this afternoon through 2 PM PDT Friday afternoon. * IMPACTS...Increased risk of ocean drowning. 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...Please check with your local authorities on potential beach closures. Steep beaches will have a higher risk of rip current activity. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming and surf conditions. Rip currents are typically more frequent and stronger in the vicinity of jetties...inlets...and piers. Swimmers caught in a rip current should swim parallel to the coast to escape the rip current before trying to swim for shore. Large breaking waves can lead to back and neck injuries. Swimmers should avoid swimming in areas of large shore break and always swim near a lifeguard. Never turn your back on the ocean! && $$
4 follow-up statements
299 WHUS46 KMTR 250306 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 806 PM PDT Thu Sep 24 2020 ...Large breaking waves and increased risk of dangerous rip currents for west to northwest facing beaches from Coastal Sonoma County to Coastal Monterey County... .Increased northwest swell will affect the coastline through 2 pm Friday afternoon before subsiding. Swell heights of 10 to 12 feet at periods of 15 to 16 seconds are expected. CAZ006-505-509-530-251600- /O.CON.KMTR.BH.S.0009.000000T0000Z-200925T2100Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast- Southern Monterey Bay and Big Sur Coast- 806 PM PDT Thu Sep 24 2020 ...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH 2 PM PDT FRIDAY AFTERNOON... * WHAT...Large breaking waves of 15 to 20 feet with dangerous rip currents expected. Steep beaches may experience breaking waves in excess of 20 feet. * WHERE...Coastline from Sonoma County southward through Monterey County. In particular west to northwest facing beaches... including but not limited to...Ocean Beach, Montara State Beach, and Marina State Beach. * WHEN...Through 2 PM PDT Friday afternoon. * IMPACTS...Increased risk of ocean drowning. 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...Please check with your local authorities on potential beach closures. Steep beaches will have a higher risk of rip current activity. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming and surf conditions. Rip currents are typically more frequent and stronger in the vicinity of jetties...inlets...and piers. Swimmers caught in a rip current should swim parallel to the coast to escape the rip current before trying to swim for shore. Large breaking waves can lead to back and neck injuries. Swimmers should avoid swimming in areas of large shore break and always swim near a lifeguard. Never turn your back on the ocean! && $$
334 WHUS46 KMTR 250926 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 226 AM PDT Fri Sep 25 2020 ...Large breaking waves and increased risk of dangerous rip currents for west to northwest facing beaches from Coastal Sonoma County to Coastal Monterey County... .Large northwest swell will affect the coastline through Friday. Swell heights of 10 to 12 feet at periods of 15 to 16 seconds are expected. Swell will subside by Friday evening. CAZ006-505-509-530-260300- /O.EXT.KMTR.BH.S.0009.000000T0000Z-200926T0300Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast- Southern Monterey Bay and Big Sur Coast- 226 AM PDT Fri Sep 25 2020 ...BEACH HAZARDS STATEMENT NOW IN EFFECT THROUGH THIS EVENING... * WHAT...Large breaking waves of 15 to 20 feet with dangerous rip currents expected. Steep beaches may experience breaking waves in excess of 20 feet. * WHERE...Coastal North Bay Including Point Reyes National Seashore, Southern Monterey Bay and Big Sur Coast, San Francisco Peninsula Coast and San Francisco Counties. * WHEN...Through this evening. * IMPACTS...Increased risk of ocean drowning. 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...Please check with your local authorities on potential beach closures. Steep beaches will have a higher risk of rip current activity. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && $$
046 WHUS46 KMTR 251152 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 452 AM PDT Fri Sep 25 2020 ...Large breaking waves and increased risk of dangerous rip currents for west to northwest facing beaches from Coastal Sonoma County to Coastal Monterey County... At 4 AM PDT Pt Piedras Blancas Buoy 28 reported a swell of 16 feet at 14 to 16 second periods. Other buoys along the central California coast were reporting 11 to 13 foot swell. Large northwest swell will affect the coastline through Friday before subsiding by Friday evening. CAZ530-260300- /O.CAN.KMTR.BH.S.0009.000000T0000Z-200926T0300Z/ /O.NEW.KMTR.SU.Y.0002.200925T1152Z-200926T0300Z/ Southern Monterey Bay and Big Sur Coast- 452 AM PDT Fri Sep 25 2020 ...HIGH SURF ADVISORY IN EFFECT UNTIL 8 PM PDT THIS EVENING... * WHAT...Large swells of 13 to 16 feet with a 15 second period. Large breaking waves of 15 to 20 feet with dangerous rip currents expected. * WHERE...Southern Monterey Bay and Big Sur Coast County. * WHEN...Until 8 PM PDT this evening. * IMPACTS...Dangerous swimming and surfing conditions and localized beach erosion. * ADDITIONAL DETAILS...Please check with your local authorities on potential beach closures. Steep beaches will have a higher risk of rip current activity. PRECAUTIONARY/PREPAREDNESS ACTIONS... Inexperienced swimmers should remain out of the water due to dangerous surf conditions. && $$ CAZ006-505-509-260300- /O.CON.KMTR.BH.S.0009.000000T0000Z-200926T0300Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast- 452 AM PDT Fri Sep 25 2020 ...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH THIS EVENING... * WHAT...Large breaking waves of 15 to 20 feet with dangerous rip currents expected. Steep beaches may experience breaking waves in excess of 20 feet. * WHERE...Coastal North Bay Including Point Reyes National Seashore, Southern Monterey Bay and Big Sur Coast, San Francisco Peninsula Coast and San Francisco Counties. * WHEN...Through this evening. * IMPACTS...Increased risk of ocean drowning. 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...Please check with your local authorities on potential beach closures. Steep beaches will have a higher risk of rip current activity. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && $$
280 WHUS46 KMTR 260247 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 747 PM PDT Fri Sep 25 2020 CAZ530-260400- /O.EXP.KMTR.SU.Y.0002.000000T0000Z-200926T0300Z/ Southern Monterey Bay and Big Sur Coast- 747 PM PDT Fri Sep 25 2020 ...HIGH SURF ADVISORY WILL EXPIRE AT 8 PM PDT THIS EVENING... Decreasing waves have been measured at the Monterey buoy which currently is at 11 feet 14 seconds. These waves are expected to continue to decrease through the evening justifying allowing the advisory to expire. However, caution is still advised while it is decreasing through Saturday morning. Never turn your back to the ocean. $$ CAZ006-505-509-260400- /O.EXP.KMTR.BH.S.0009.000000T0000Z-200926T0300Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast- 747 PM PDT Fri Sep 25 2020 ...BEACH HAZARDS STATEMENT WILL EXPIRE AT 8 PM PDT THIS EVENING... Waves continue to decrease and are being measured by buoys between 10 to 11 feet from 12-14 seconds. The decreasing nature of the wave heights is justifying allowing the statement to expire. However, caution is still advised through Saturday morning for breaking waves and rip currents. 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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 24, 2:09 PM PDT | Small Craft Advisory | MTR | 55 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.