Alert archive / California / High Surf Warnings in 2023

High Surf Warning 4, NWS San Francisco Bay Area, CA

December 25, 20236 counties in California

NWS San Francisco Bay Area, CA issued this high surf warning at Dec 25, 2023, 11:44 PM PST for 6 counties in California. It took effect at Dec 28, 2023, 3:00 AM PST. It was in force for 24 hr. 9 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Dec 25, 2023, 11:44 PM PST (07:44 UTC)
In effect from
Dec 28, 2023, 3:00 AM PST
Expired
Dec 29, 2023, 3:00 AM PST
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 07:48 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.

What was reported inside it

TimeReportWhereRemark
Dec 28, 6:59 AM PSTHIGH SURF2 S Live Oak, CAEast Cliff Dr at Moran Beach shut down due to large waves washing over road and a large log washed onto the road.
Dec 28, 7:30 AM PSTHIGH SURF2 S Aptos, CADamage to several homes and businesses.
Dec 28, 7:43 AM PSTHIGH SURF3 Sse Del Monte Forest, CA17 Mile Drive closed down between Spanish Bay and Bird Rock due to large waves crashing up onto roadway and flooding the road. CHP notes that the waves are leaving boulders on the road.
Dec 28, 9:40 AM PSTHIGH SURF1 Sw Capitola, CANew damage to the repairs being made along East Cliff Drive from Januarys high surf.
Dec 28, 10:00 AM PSTHIGH SURF1 Se Santa Cruz, CAHigh surf damaged the Santa Cruz pier. Damage to the structure as well as the sprinkle system and other infrastructure.
Dec 28, 10:23 AM PSTHIGH SURF3 E Bolinas, CANews report from Fox2 KTVU of homes in Stinson Beach being evacuated as a result of coastal flooding and high surf.
Dec 28, 11:15 AM PSTHIGH SURF4 Sw Watsonville, CARoadway flooding and closure as a result of seawater coming up over the road. Beach Road and Rio Boca Rd.
Dec 28, 1:00 PM PSTHIGH SURF2 Nnw Pacifica, CASeveral people knocked off their feet by large waves.
Dec 28, 2:00 PM PSTHIGH SURF3 Sse Del Monte Forest, CAHigh surf caused flooding along the Carmel Lagoon. Carmelo Street and Camino Real both flooded.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Vandenberg AFB, CA (KVBG), launched 00:00Z, 7.7 hours before the alert went out and 349 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, Vandenberg AFB, CA at 00:00Z on 2023-12-26Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Vandenberg AFB, CA at 00:00Z on 2023-12-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.19395878Sfc1 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
1968 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

049 
WHUS46 KMTR 260744
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
1144 PM PST Mon Dec 25 2023

CAZ006-262100-
/O.NEW.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0022.231226T1700Z-231226T2100Z/
San Francisco-
1144 PM PST Mon Dec 25 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO 1 PM PST
TUESDAY...
...HIGH SURF WARNING IN EFFECT FROM 3 AM THURSDAY TO 3 AM PST
FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerously large breaking
  waves of 20 to 25 ft.

* WHERE...San Francisco County.

* WHEN...For the Coastal Flood Advisory, from 9 AM to 1 PM PST 
  Tuesday. For the High Surf Warning, from 3 AM Thursday to 3 AM 
  PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:07
  am PST Tuesday between 7.0 to 7.5 feet above MLLW, resulting in
  minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During the coastal flood: If travel is required, allow extra time
as some roads may be closed. Do not drive around barricades or 
through water of unknown depth. Take the necessary actions to 
protect flood-prone property.

Remain out of the water during the High Surf to avoid hazardous 
swimming conditions. Large breaking waves along the coast will 
lead to increased run- up on beaches with waves topping and 
washing over large rocks and jetties. These large waves can be 
erratic and unpredictable. Use extra caution near the surf zone as
these large waves will be capable of sweeping people into the 
water. Avoid rocks and jetties. Avoid steep beaches. Stay much 
farther back from the water and never turn your back on the ocean.

&&

$$

CAZ505-509-529-530-262100-
/O.NEW.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
1144 PM PST Mon Dec 25 2023

...HIGH SURF WARNING IN EFFECT FROM 3 AM THURSDAY TO 3 AM PST
FRIDAY...

* WHAT...Dangerously large breaking waves of of 20 to 26 ft.

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

* WHEN...From 3 AM Thursday to 3 AM PST Friday.

* IMPACTS...Breaking waves can sweep people off jetties and 
  docks, and into dangerous seas. Life-threatening swimming 
  conditions and significant beach erosion can be expected.

* ADDITIONAL DETAILS...Large west waves will arrive Thursday
  morning and last into the late morning before slowly reducing
  into late that night. Beaches are at risk for large turbulent 
  shore break and strong currents.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain out of the water during the High Surf to avoid hazardous 
swimming conditions. Large breaking waves along the coast will 
lead to increased run- up on beaches with waves topping and 
washing over large rocks and jetties. These large waves can be 
erratic and unpredictable. Use extra caution near the surf zone as
these large waves will be capable of sweeping people into the 
water. Avoid rocks and jetties. Avoid steep beaches. Stay much 
farther back from the water and never turn your back on the ocean.


&&

$$

CAZ506-508-262100-
/O.CON.KMTR.CF.Y.0022.231226T1700Z-231226T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
1144 PM PST Mon Dec 25 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO 1 PM PST
TUESDAY...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...From 9 AM to 1 PM PST Tuesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:07
  am PST Tuesday between 7.0 to 7.5 feet above MLLW, resulting in
  minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
9 follow-up statements
483 
WHUS46 KMTR 262016
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
1216 PM PST Tue Dec 26 2023

CAZ006-270430-
/O.NEW.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0022.000000T0000Z-231226T2100Z/
San Francisco-
1216 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 1 PM PST THIS
AFTERNOON...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 AM WEDNESDAY TO 3 AM
PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the first Coastal Flood Advisory, minor coastal
  flooding expected in the Bay. For the second Coastal Flood
  Advisory, minor coastal flooding expected on the coast. For the
  High Surf Warning, dangerously large breaking waves of 25 to 30
  ft.

* WHERE...San Francisco County.

* WHEN...For the first Coastal Flood Advisory, until 1 PM PST 
  this afternoon. For the second Coastal Flood Advisory, from 9 
  AM Wednesday to 3 AM PST Friday. For the High Surf Warning, 
  from 3 AM Thursday to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During the coastal flood: If travel is required, allow extra time
as some roads may be closed. Do not drive around barricades or 
through water of unknown depth. Take the necessary actions to 
protect flood-prone property.

Remain out of the water during the High Surf to avoid hazardous 
swimming conditions. Large breaking waves along the coast will 
lead to increased run-up on beaches with waves topping and 
washing over large rocks and jetties. These large waves can be 
erratic and unpredictable. Use extra caution near the surf zone as
these large waves will be capable of sweeping people into the 
water. Avoid rocks and jetties. Avoid steep beaches. Stay much 
farther back from the water and never turn your back on the ocean.

&&

$$

CAZ505-509-529-530-270430-
/O.NEW.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
1216 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 AM WEDNESDAY TO 3 AM
PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerous large breaking 
  waves of 25 to 30 ft.

* WHERE...Coastal North Bay Including Point Reyes National
  Seashore, San Francisco Peninsula Coast, Northern Monterey Bay
  and Southern Monterey Bay and Big Sur Coast Counties. The
  Breaking waves will be highest along W and NW facing beaches.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 
  3 AM PST Friday. For the High Surf Warning, from 3 AM Thursday 
  to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Large west waves will arrive Thursday
  morning and last into the late morning before slowly reducing
  into late that night. Beaches are at risk for large turbulent 
  shore break and strong currents.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During the coastal flood: If travel is required, allow extra time
as some roads may be closed. Do not drive around barricades or 
through water of unknown depth. Take the necessary actions to 
protect flood-prone property.

Remain out of the water during the High Surf to avoid hazardous 
swimming conditions. Large breaking waves along the coast will 
lead to increased run-up on beaches with waves topping and 
washing over large rocks and jetties. These large waves can be 
erratic and unpredictable. Use extra caution near the surf zone as
these large waves will be capable of sweeping people into the 
water. Avoid rocks and jetties. Avoid steep beaches. Stay much 
farther back from the water and never turn your back on the ocean.

&&

$$

CAZ506-508-270430-
/O.NEW.KMTR.CF.Y.0023.231227T1700Z-231227T2100Z/
/O.CON.KMTR.CF.Y.0022.000000T0000Z-231226T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
1216 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 1 PM PST THIS
AFTERNOON...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 AM TO 1 PM PST
WEDNESDAY...

* WHAT...For the first Coastal Flood Advisory, minor coastal 
  flooding. For the second Coastal Flood Advisory, minor coastal 
  flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...For the first Coastal Flood Advisory, until 1 PM PST 
  this afternoon. For the second Coastal Flood Advisory, from 9 
  AM to 1 PM PST Wednesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
743 
WHUS46 KMTR 262104
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
104 PM PST Tue Dec 26 2023

CAZ006-270515-
/O.EXP.KMTR.CF.Y.0022.000000T0000Z-231226T2100Z/
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
San Francisco-
104 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM WEDNESDAY
TO 3 AM PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...
...PREVIOUS COASTAL FLOOD ADVISORY HAS EXPIRED...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 ft.

* WHERE...San Francisco County.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 3
  AM PST Friday. For the High Surf Warning, from 3 AM Thursday to
  3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During the coastal flood: If travel is required, allow extra time
as some roads may be closed. Do not drive around barricades or 
through water of unknown depth. Take the necessary actions to 
protect flood-prone property.

Remain out of the water during the High Surf to avoid hazardous 
swimming conditions. Large breaking waves along the coast will 
lead to increased run-up on beaches with waves topping and 
washing over large rocks and jetties. These large waves can be 
erratic and unpredictable. Use extra caution near the surf zone as
these large waves will be capable of sweeping people into the 
water. Avoid rocks and jetties. Avoid steep beaches. Stay much 
farther back from the water and never turn your back on the ocean.

&&

$$

CAZ506-508-270515-
/O.EXP.KMTR.CF.Y.0022.000000T0000Z-231226T2100Z/
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231227T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
104 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO 1 PM PST
WEDNESDAY...
...PREVIOUS COASTAL FLOOD ADVISORY HAS EXPIRED...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...For the first Coastal Flood Advisory, until 1 PM PST 
  this afternoon. For the second Coastal Flood Advisory, from 9 
  AM to 1 PM PST Wednesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$

CAZ505-509-529-530-270515-
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
104 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM WEDNESDAY
TO 3 AM PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding 
  expected. For the High Surf Warning, dangerous large breaking 
  waves of 25 to 30 ft.

* WHERE...Coastal North Bay Including Point Reyes National 
  Seashore, San Francisco Peninsula Coast, Northern Monterey Bay 
  and Southern Monterey Bay and Big Sur Coast Counties. The 
  Breaking waves will be highest along W and NW facing beaches.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 
  3 AM PST Friday. For the High Surf Warning, from 3 AM Thursday 
  to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Large west waves will arrive Thursday 
  morning and last into the late morning before slowly reducing 
  into late that night. Beaches are at risk for large turbulent 
  shore break and strong currents.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During the coastal flood: If travel is required, allow extra time
as some roads may be closed. Do not drive around barricades or
through water of unknown depth. Take the necessary actions to
protect flood-prone property.

Remain out of the water during the High Surf to avoid hazardous
swimming conditions. Large breaking waves along the coast will
lead to increased run-up on beaches with waves topping and
washing over large rocks and jetties. These large waves can be
erratic and unpredictable. Use extra caution near the surf zone
as these large waves will be capable of sweeping people into the
water. Avoid rocks and jetties. Avoid steep beaches. Stay much
farther back from the water and never turn your back on the
ocean.

&&

$$
237 
WHUS46 KMTR 270330
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
730 PM PST Tue Dec 26 2023

CAZ006-505-509-529-530-271330-
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
730 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM WEDNESDAY
TO 3 AM PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerously large breaking
  waves of 25 to 30 ft.

* 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 
  Counties.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 
  3 AM PST Friday. For the High Surf Warning, from 3 AM Thursday 
  to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ506-508-271330-
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231227T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
730 PM PST Tue Dec 26 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO 1 PM PST
WEDNESDAY...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...From 9 AM to 1 PM PST Wednesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions. High tide will peak about 10:46
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
138 
WHUS46 KMTR 271129
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
329 AM PST Wed Dec 27 2023

CAZ006-505-509-529-530-272100-
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
329 AM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM THIS
MORNING TO 3 AM PST FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding 
  expected. For the High Surf Warning, dangerously large 
  breaking waves of 25 to 30 ft.

* 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 
  Counties.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 
  3 AM PST Friday. For the High Surf Warning, from 3 AM Thursday 
  to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot 
  higher than tidal predictions. High tide will peak about 10:46 
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ506-508-272100-
/O.CON.KMTR.CF.Y.0023.231227T1700Z-231227T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
329 AM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM THIS
MORNING TO 1 PM PST THIS AFTERNOON...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...From 9 AM to 1 PM PST Wednesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot 
  higher than tidal predictions. High tide will peak about 10:46 
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
290 
WHUS46 KMTR 272116
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
116 PM PST Wed Dec 27 2023

CAZ506-508-280530-
/O.EXP.KMTR.CF.Y.0023.000000T0000Z-231227T2100Z/
/O.NEW.KMTR.CF.Y.0024.231227T2116Z-231227T2300Z/
/O.NEW.KMTR.CF.Y.0025.231228T1800Z-231228T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
116 PM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY IN EFFECT UNTIL 3 PM PST THIS
AFTERNOON...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 10 AM TO 1 PM PST
THURSDAY...

* WHAT...For the first Coastal Flood Advisory, minor coastal 
  flooding. For the second Coastal Flood Advisory, minor coastal 
  flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...For the first Coastal Flood Advisory, until 3 PM PST 
  this afternoon. For the second Coastal Flood Advisory, from 10 
  AM to 1 PM PST Thursday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions due to strong southerly winds.
  High tide will peak about 11:26 am PST Thursday between 7.0 to
  7.5 feet above MLLW, resulting in minor coastal flooding for
  low-lying, flood-prone spots adjacent to the San Francisco Bay.
  Strong southerly winds and increasing surf will contribute to 
  coastal flooding along the Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$

CAZ006-505-509-529-530-280530-
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.000000T0000Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
116 PM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 3 AM PST
FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerously large breaking
  waves of 28 to 33 ft with up to 40 ft possible at favored
  locations. High surf will subside Friday before another large swell
  train arrives Saturday.

* 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 
  Counties.

* WHEN...For the Coastal Flood Advisory, from 9 AM Wednesday to 
  3 AM PST Friday. For the High Surf Warning, from 3 AM Thursday 
  to 3 AM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life- 
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot 
  higher than tidal predictions. High tide will peak about 10:46 
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$
202 
WHUS46 KMTR 280451
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
851 PM PST Wed Dec 27 2023

CAZ006-505-509-529-530-281700-
/O.CON.KMTR.SU.W.0004.231228T1100Z-231229T1100Z/
/O.CON.KMTR.CF.Y.0023.000000T0000Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
851 PM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 3 AM PST
FRIDAY...
...HIGH SURF WARNING REMAINS IN EFFECT FROM 3 AM THURSDAY TO 3 AM
PST FRIDAY...

* WHAT...For the Coastal Flood Advisory, minor coastal flooding
  expected. For the High Surf Warning, dangerously large breaking
  waves of 28 to 33 ft with up to 40 ft possible at favored
  locations. High surf will subside Friday before another large swell
  train arrives Saturday.

* 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 
  Counties.

* WHEN...For the Coastal Flood Advisory, until 3 AM PST Friday. 
  For the High Surf Warning, from 3 AM Thursday to 3 AM PST 
  Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot 
  higher than tidal predictions. High tide will peak about 10:46 
  am PST Wednesday between 7.0 to 7.5 feet above MLLW, resulting 
  in minor coastal flooding for low-lying, flood-prone spots 
  adjacent to the San Francisco Bay. Strong southerly winds and 
  increasing surf will contribute to coastal flooding along the 
  Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ506-508-281700-
/O.CON.KMTR.CF.Y.0025.231228T1800Z-231228T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
851 PM PST Wed Dec 27 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 10 AM TO 1 PM
PST THURSDAY...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...From 10 AM to 1 PM PST Thursday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot
  higher than tidal predictions due to strong southerly winds.
  High tide will peak about 11:26 am PST Thursday between 7.0 to
  7.5 feet above MLLW, resulting in minor coastal flooding for
  low-lying, flood-prone spots adjacent to the San Francisco Bay.
  Strong southerly winds and increasing surf will contribute to 
  coastal flooding along the Pacific Ocean beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
226 
WHUS46 KMTR 281610
CFWMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Coastal Hazard Message
National Weather Service San Francisco CA
810 AM PST Thu Dec 28 2023

CAZ006-505-509-529-530-290015-
/O.UPG.KMTR.CF.Y.0023.000000T0000Z-231229T1100Z/
/O.NEW.KMTR.CF.W.0002.231228T1610Z-231228T2300Z/
/O.CON.KMTR.SU.W.0004.000000T0000Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
810 AM PST Thu Dec 28 2023

...COASTAL FLOOD WARNING IN EFFECT UNTIL 3 PM PST THIS
AFTERNOON...
...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 3 AM PST FRIDAY...

* WHAT...For the Coastal Flood Warning, significant coastal
  flooding. For the High Surf Warning, dangerously large breaking
  waves of 28 to 33 ft with up to 40 ft possible at favored
  locations. 

* 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 
  Counties.

* WHEN...For the Coastal Flood Warning, until 3 PM PST this 
  afternoon. For the High Surf Warning, until 3 AM PST Friday.

* IMPACTS...Numerous roads may be closed. Low lying property 
  including homes, businesses, and some critical infrastructure 
  will be inundated. Some shoreline erosion will occur. Breaking 
  waves can sweep people off jetties and docks, and into 
  dangerous seas. Life-threatening swimming conditions and 
  significant beach erosion can be expected.

* ADDITIONAL DETAILS...Reports of coastal flooding are coming in
  early this morning including some evacuations. Expect the worse
  impacts from inundation in the late morning around high tide. 
  The high surf will subside Friday before another large swell 
  train arrives Saturday. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take the necessary actions to protect flood-prone property. If
travel is required, do not drive around barricades or through
water of unknown depth.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$

CAZ506-508-282100-
/O.CON.KMTR.CF.Y.0025.231228T1800Z-231228T2100Z/
North Bay Interior Valleys-San Francisco Bay Shoreline-
810 AM PST Thu Dec 28 2023

...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 1 PM PST THIS
AFTERNOON...

* WHAT...Minor coastal flooding expected.

* WHERE...North Bay Interior Valleys and San Francisco Bay 
  Shoreline Counties.

* WHEN...From 10 AM to 1 PM PST Thursday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected.

* ADDITIONAL DETAILS...Tidal levels are running around 1 foot 
  higher than tidal predictions due to strong southerly winds. 
  High tide will peak about 11:26 am PST Thursday between 7.0 to 
  7.5 feet above MLLW, resulting in minor coastal flooding for 
  low- lying, flood-prone spots adjacent to the San Francisco 
  Bay. Strong southerly winds and increasing surf will 
  contribute to coastal flooding along the Pacific Ocean 
  beginning Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

&&

$$
166 
WHUS46 KMTR 282300
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
300 PM PST Thu Dec 28 2023

CAZ006-505-509-529-530-291115-
/O.EXP.KMTR.CF.W.0002.000000T0000Z-231228T2300Z/
/O.NEW.KMTR.CF.Y.0026.231228T2300Z-231229T2200Z/
/O.CON.KMTR.SU.W.0004.000000T0000Z-231229T1100Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
300 PM PST Thu Dec 28 2023

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 3 AM PST FRIDAY...
...COASTAL FLOOD ADVISORY IN EFFECT UNTIL 2 PM PST FRIDAY...

* WHAT...For the High Surf Warning, dangerously large breaking
  waves of 28 to 33 ft, with up to 40 ft possible at favored 
  locations. For the Coastal Flood Advisory, minor coastal 
  flooding expected from the high surf.

* 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 
  Counties.

* WHEN...For the High Surf Warning, until 3 AM PST Friday. For 
  the Coastal Flood Advisory, until 2 PM PST Friday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Breaking waves can sweep 
  people off jetties and docks, and into dangerous seas. Life-
  threatening swimming conditions and significant beach erosion 
  can be expected.

* ADDITIONAL DETAILS...Numerous roads may be closed. Low lying 
  property including homes, businesses, and some critical 
  infrastructure will be inundated. Some shoreline erosion will 
  occur. Breaking waves can sweep people off jetties and docks, 
  and into dangerous seas. Life-threatening swimming conditions 
  and significant beach erosion can be expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Everyone should remain out of the water due to life-threatening
surf conditions. Stay off of jetties, piers, and other waterside
infrastructure.

&&

$$
178 
WHUS46 KMTR 291112
CFWMTR

Coastal Hazard Message
National Weather Service San Francisco CA
312 AM PST Fri Dec 29 2023

CAZ006-505-509-529-530-292200-
/O.EXP.KMTR.SU.W.0004.000000T0000Z-231229T1100Z/
/O.NEW.KMTR.SU.Y.0010.231229T1112Z-231230T0200Z/
/O.CON.KMTR.CF.Y.0026.000000T0000Z-231229T2200Z/
San Francisco-
Coastal North Bay Including Point Reyes National Seashore-
San Francisco Peninsula Coast-Northern Monterey Bay-
Southern Monterey Bay and Big Sur Coast-
312 AM PST Fri Dec 29 2023

...HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM PST THIS EVENING...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 2 PM PST THIS
AFTERNOON...
...HIGH SURF WARNING HAS EXPIRED...

* WHAT...For the High Surf Advisory, large breaking waves of 15 to
  19 feet. For the Coastal Flood Advisory, minor coastal  
  flooding.

* 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 
  Counties.

* WHEN...For the High Surf Advisory, until 6 PM PST this 
  evening. For the Coastal Flood Advisory, until 2 PM PST this 
  afternoon.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Dangerous swimming and 
  surfing conditions and localized beach erosion.

* ADDITIONAL DETAILS...Roads may be closed. Low lying property
  including homes, businesses, and some critical infrastructure
  may be inundated. Some shoreline erosion will occur. Breaking 
  waves can sweep people off jetties and docks, and into dangerous
  seas. Life-threatening swimming conditions and significant 
  beach erosion can be expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.

Inexperienced swimmers should remain out of the water due to
dangerous surf conditions.

&&

$$

What forecasters said that day

The local office's own words before this high surf warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Francisco Bay Area, CA wrote its last area forecast discussion before this high surf warning went out at Dec 25, 9:54 PM PST, 1 hour 50 minutes earlier.

Area forecast discussion, Dec 25, 9:54 PM PST, 1 hour 50 minutes before
Area Forecast Discussion
National Weather Service San Francisco CA
954 PM PST Mon Dec 25 2023

...New AVIATION...

.SYNOPSIS...
Issued at 136 PM PST Mon Dec 25 2023

The Bay Area is enjoying some benign weather on the back side of a
high pressure system. Similar conditions will persist Tuesday
before a drastic change. Rain, wind and dangerous high surf are
in the forecast later this week.

&&

.UPDATE...
Issued at 941 PM PST Mon Dec 25 2023

The Coastal Flood Advisory remains in effect for San Francisco,
the San Francisco Bay Shoreline and North Bay Interior Valleys
from 9 am to 1 pm PST Tuesday. The Beach Hazards Statement was
allowed to expire earlier this evening. From mid to late week
increasingly larger swell arrive along our coast, mainly a westerly
swell from a Pacific storm system.

For late tonight and Tuesday morning lower level cooling may result
in patches of fog in the North Bay valleys to the Delta. A patch
or two of fog may develop elsewhere though cirrus clouds passing
overhead are slowing nocturnal radiative cooling to space which
should help limit fog development. Rain chances remain in the
forecast for Wednesday and late week.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 136 PM PST Mon Dec 25 2023

High clouds are increasing ahead of an Eastern Pacific cold front.
All guidance agrees that this system will weaken before impacting
the Bay Area. Nonetheless, the swell generated from this system
is bringing large waves to the coast today, and a Beach Hazards
Statement is in effect until 7PM. With a full moon tonight, minor
high tide flooding is expected in the San Francisco Bay late
Tuesday morning. Temperatures are generally in the upper 50s to
low 60s and will stay above average overnight thanks to the high
clouds and increasing southerly winds.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 136 PM PST Mon Dec 25 2023

The influence of the upper level ridge continues to bring benign
weather through Tuesday with high temperatures about the same as
today. Everything changes on Wednesday as a storm force low
pressure system in the Eastern Pacific begins to encroach on the
Bay Area. This system is not expected to reach the coast, but
strong southerly winds and periods of warm sector rain are
expected through the day Wednesday. Total rain accumulation of
0.5-1.5" are expected in the North Bay Wednesday, with 0.1-0.5"
through the rest of the Bay Area. The wind and rain will die down
Thursday, just as very large swell from this system reaches the
coast, with breaking waves up to 22 ft on west-facing beaches.
These conditions are life threatening.

Another system comes through overnight Thursday into Friday, with
rain totals up to 2" possible in the coastal ranges, and
widespread rain totals of 0.5-1". Stronger southerly winds are
expected again, though with peak gusts around 35 mph, they won't
be quite as strong as Wednesday. High swell returns Saturday,
though not as high as Thursday with breaking waves in the 14-17 ft
range.

The active pattern is expected to continue into the New Year, with
CPC guidance suggesting that it's more likely than not that
precipitation totals will fall above the seasonal average into the
first week of 2024. Remembering that long range guidance does not
indicate how much rain will fall, where rain will fall, or how
intense the rain will be, the best advice for this time of year is
to make sure gutters and storm drains are clear, and to follow
forecast updates from a trusted source.

&&

.AVIATION...
(06Z TAFS)
Issued at 954 PM PST Mon Dec 25 2023

Currently VFR at all TAF sites. There is low to moderate confidence
that patchy dense fog will impact APC and STS overnight. The TAFs
are heavily banking on the cooling trend that is evident on the
Bodega Bay Profiler as well as high clouds not proving to be too
much for fog development. For timing, later is better is what was
decided as it was a compromise between models/guidance and what is
actually happening. The rest of the terminals are forecast to remain
VFR through the TAF period.

Vicinity of SFO...Currently VFR with breezy offshore flow and high
clouds. Terminal is forecast to remain VFR through the TAF period.
Winds will remain offshore overnight before becoming southerly ahead
of the cold front tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with breezy drainage flow and
high clouds at both TAF sites. Drainage flow will persist throughout
the night before winds become breezy and onshore tomorrow afternoon.
Stratus did impact the terminals between about 01Z and 04Z, but they
are forecast to remain VFR through the rest of the TAF period.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 904 PM PST Mon Dec 25 2023

A high pressure system over the coastal waters and bays will move
eastward early this week. A low pressure system over the eastern
Pacific will result in a cold front moving through and gusty
southerly winds developing Wednesday, strongest winds across the
northern outer waters where a gale warning will be in effect.
Winds gradually  decreasing by Thursday. Otherwise increasingly
large westerly swell  arriving from mid to late week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory from 9 AM to 1 PM PST Tuesday for CAZ006-
     506-508.

PZ...Small Craft Advisory until 9 AM PST Wednesday for Mry Bay-Pigeon
     Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt
     Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-
     10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 PM PST Tuesday for Pt Arena to Pt
     Reyes 10-60 NM.

     Gale Warning from 9 PM Tuesday to 9 AM PST Wednesday for Pt
     Arena to Pt Reyes 10-60 NM.

&&

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Sarment
MARINE...Canepa

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 26, 12:16 PM PSTCoastal Flood AdvisoryMTRAlameda, Contra Costa, Marin, Monterey, Napa, City and County of San Francisco and 4 more44 hr

Nearby

High Surf Warnings in California, 2023Every high surf warning in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.