Alert archive / California / Beach Hazards Statements in 2021
Beach Hazards Statement 7, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this beach hazards statement at Sep 27, 2021, 11:31 AM PDT for 6 counties in California. It took effect at Sep 27, 2021, 11:00 PM PDT. It was in force for 24 hr.
The area
The counties it named.
The facts
- Issued
- Sep 27, 2021, 11:31 AM PDT (18:31 UTC)
- In effect from
- Sep 27, 2021, 11:00 PM PDT
- Expired
- Sep 28, 2021, 11:00 PM 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 18:31 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, 6.5 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
- 488 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -18 m²/s²
- 0-3 km storm-relative helicity
- 27 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
346 WHUS46 KMTR 271831 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 1131 AM PDT Mon Sep 27 2021 ...Increasing risk of large shore break, wave run up, and rip currents from late Monday night to late Tuesday night... .After a fairly quiet summer in terms of swell, the first larger northwest swell of the season will arrive tonight. Expect an increased risk of moderate to large breaking waves and stronger rip currents. Additionally, increasing winds behind a cold frontal passage in combination with the building swell may cause waves to run up farther along area beaches than usual. This hazard is primarily for west to northwest facing beaches. Caution is urged. Northwest swell will gradually subside on Wednesday. CAZ006-505-509-529-530-280245- /O.NEW.KMTR.BH.S.0007.210928T0600Z-210929T0600Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast-Northern Monterey Bay- Southern Monterey Bay and Big Sur Coast- 1131 AM PDT Mon Sep 27 2021 ...BEACH HAZARDS STATEMENT IN EFFECT FROM 11 PM PDT THIS EVENING THROUGH TUESDAY EVENING... * WHAT...Northwest swell 8 to 10 feet at 13 to 15 seconds expected. Breaking waves of 13 to 17 feet possible. * WHERE...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. * WHEN...From 11 PM PDT this evening to 11 PM PDT Tuesday evening. * IMPACTS...Increased risk of moderate to large breaking waves, strong rip currents, and wave run up. * ADDITIONAL DETAILS...People walking along the beach should never turn their back to the sea. Avoid fishing from rocks or jetties. The coastal waters remain cold. Cold water shock may cause cardiac arrest and it also can cause an involuntary gasp reflex causing drowning, even for a good swimmer. The surf zone will be dangerous due to larger breaking waves and strong rip currents. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && $$
4 follow-up statements
780 WHUS46 KMTR 280213 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 713 PM PDT Mon Sep 27 2021 ...Increasing risk of large shore break, wave run up, and rip currents from late Monday night to late Tuesday night... .After a fairly quiet summer in terms of swell, the first larger northwest swell of the season will arrive tonight. Expect an increased risk of moderate to large breaking waves and stronger rip currents. Additionally, increasing winds behind a cold frontal passage in combination with the building swell may cause waves to run up farther along area beaches than usual. This hazard is primarily for west to northwest facing beaches. Caution is urged. Northwest swell will gradually subside on Wednesday. CAZ006-505-509-529-530-281300- /O.CON.KMTR.BH.S.0007.210928T0600Z-210929T0600Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast-Northern Monterey Bay- Southern Monterey Bay and Big Sur Coast- 713 PM PDT Mon Sep 27 2021 ...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 11 PM PDT THIS EVENING THROUGH TUESDAY EVENING... * WHAT...Northwest swell 8 to 10 feet at 13 to 15 seconds expected. Breaking waves of 13 to 17 feet possible. * WHERE...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. * WHEN...From 11 PM PDT tonight through Tuesday evening. * IMPACTS...Increased risk of moderate to large breaking waves, strong rip currents, and wave run up. * ADDITIONAL DETAILS...People walking along the beach should never turn their back to the sea. Avoid fishing from rocks or jetties. The coastal waters remain cold. Cold water shock may cause cardiac arrest and it also can cause an involuntary gasp reflex causing drowning, even for a good swimmer. The surf zone will be dangerous due to larger breaking waves and strong rip currents. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && ED $$
320 WHUS46 KMTR 281213 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 513 AM PDT Tue Sep 28 2021 ...Increasing risk of large shore break, wave run up, and rip currents from late Monday night to late Tuesday night... .The first larger northwest swell of the season continues. Expect an increased risk of moderate to large breaking waves and stronger rip currents. Additionally, increasing winds behind a cold frontal passage in combination with the building swell may cause waves to run up farther along area beaches than usual. This hazard is primarily for west to northwest facing beaches. Caution is urged. Northwest swell will gradually subside on Wednesday. CAZ006-505-509-529-530-282100- /O.CON.KMTR.BH.S.0007.000000T0000Z-210929T0600Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast-Northern Monterey Bay- Southern Monterey Bay and Big Sur Coast- 513 AM PDT Tue Sep 28 2021 ...BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH THIS EVENING... * WHAT...Northwest swell 8 to 10 feet at 13 to 15 seconds expected. Breaking waves of 13 to 17 feet possible. * WHERE...West to northwest facing beaches along the coast from Sonoma County through Monterey County including but not limited to; Ocean Beach, Montara State Beach, and Marina State Beach. * WHEN...From now through Tuesday evening. * IMPACTS...Increased risk of moderate to large breaking waves, strong rip currents, and wave run up. * ADDITIONAL DETAILS...People walking along the beach should never turn their back to the sea. Avoid fishing from rocks or jetties. The coastal waters remain cold. Cold water shock may cause cardiac arrest and it also can cause an involuntary gasp reflex causing drowning, even for a good swimmer. The surf zone will be dangerous due to larger breaking waves and strong rip currents. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && BKM $$
967 WHUS46 KMTR 282001 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 101 PM PDT Tue Sep 28 2021 ...Increased risk of large shore break, wave run up, and rip currents until late Tuesday night... .The first larger northwest swell of the season continues. Expect an increased risk of moderate to large breaking waves and stronger rip currents. Additionally, breezy winds behind an earlier cold frontal passage in combination with the building swell may cause waves to run up farther along area beaches than usual. This hazard is primarily for west to northwest facing beaches. Caution is urged. Northwest swell will gradually subside on Wednesday. CAZ006-505-509-529-530-290600- /O.CON.KMTR.BH.S.0007.000000T0000Z-210929T0600Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast-Northern Monterey Bay- Southern Monterey Bay and Big Sur Coast- 101 PM PDT Tue Sep 28 2021 ...BEACH HAZARDS STATEMENT REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING... * WHAT...Northwest swell 8 to 10 feet at 13 to 15 seconds expected. Breaking waves of 13 to 17 feet possible. * WHERE...West to northwest facing beaches along the coast from Sonoma County through Monterey County including but not limited to; Ocean Beach, Montara State Beach, and Marina State Beach. * WHEN...From now through Tuesday evening. * IMPACTS...Increased risk of moderate to large breaking waves, strong rip currents, and wave run up. * ADDITIONAL DETAILS...People walking along the beach should never turn their back to the sea. Avoid fishing from rocks or jetties. The coastal waters remain cold. Cold water shock may cause cardiac arrest and it also can cause an involuntary gasp reflex causing drowning, even for a good swimmer. The surf zone will be dangerous due to larger breaking waves and strong rip currents. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain out of the water to avoid hazardous swimming conditions. && $$
888 WHUS46 KMTR 290550 CFWMTR Coastal Hazard Message National Weather Service San Francisco CA 1050 PM PDT Tue Sep 28 2021 CAZ006-505-509-529-530-290700- /O.EXP.KMTR.BH.S.0007.000000T0000Z-210929T0600Z/ San Francisco- Coastal North Bay Including Point Reyes National Seashore- San Francisco Peninsula Coast-Northern Monterey Bay- Southern Monterey Bay and Big Sur Coast- 1050 PM PDT Tue Sep 28 2021 ...BEACH HAZARDS STATEMENT WILL EXPIRE AT 11 PM PDT THIS EVENING... Northwest swell gradually subsiding tonight and Wednesday. $$
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 27, 2:26 AM PDT | Small Craft Advisory | MTR | 4 days |
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.