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Updated:December 30, 2025 12:16 am PST

Coastal Flood Advisory COASTAL FLOOD ADVISORY  
Los Angeles County

  Effective: Mon, 12/29 1:13pm Severity: Minor
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 5:00am Certainty: Likely

Areas Affected: San Francisco - Coastal North Bay Including Point Reyes National Seashore - North Bay Interior Valleys - San Francisco Bay Shoreline - San Francisco Peninsula Coast - Northern Monterey Bay - Southern Monterey Bay and Big Sur Coast
 
Alert Details:
* WHAT...Up to 1.8 ft of inundation above ground level is
possible in low-lying areas near shorelines and tidal waterways.

* WHERE...San Francisco Bay and San Pablo Bay shoreline, Monterey
Bay shoreline, and the Pacific Coast.

* WHEN...From 5 AM Wednesday to 2 PM PST Sunday.

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

* ADDITIONAL DETAILS...At the San Francisco tidal gauge, high tide
is expected to be:
1.5 ft above normal (7.36 ft MLLW) at 7:51 AM Wednesday 12/31
1.7 ft above normal (7.55 ft MLLW) at 8:41 AM Thursday 1/1
1.8 ft above normal (7.66 ft MLLW) at 9:34 AM Friday 1/2
1.8 ft above normal (7.63 ft MLLW) at 10:26 AM Saturday 1/3
1.6 ft above normal (7.42 ft MLLW) at 11:18 AM Sunday 1/4
These predictions include 0.5 feet of storm surge that will
enhance the astronomical tide and flooding threat. High tide
varies up to 90 minutes earlier or later along the Pacific
Coast and through the San Francisco Bay, respectively.

Information:
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.
Coastal Flood Advisory COASTAL FLOOD ADVISORY  
Marin County

  Effective: Mon, 12/29 1:13pm Severity: Minor
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 5:00am Certainty: Likely

Areas Affected: San Francisco - Coastal North Bay Including Point Reyes National Seashore - North Bay Interior Valleys - San Francisco Bay Shoreline - San Francisco Peninsula Coast - Northern Monterey Bay - Southern Monterey Bay and Big Sur Coast
 
Alert Details:
* WHAT...Up to 1.8 ft of inundation above ground level is
possible in low-lying areas near shorelines and tidal waterways.

* WHERE...San Francisco Bay and San Pablo Bay shoreline, Monterey
Bay shoreline, and the Pacific Coast.

* WHEN...From 5 AM Wednesday to 2 PM PST Sunday.

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

* ADDITIONAL DETAILS...At the San Francisco tidal gauge, high tide
is expected to be:
1.5 ft above normal (7.36 ft MLLW) at 7:51 AM Wednesday 12/31
1.7 ft above normal (7.55 ft MLLW) at 8:41 AM Thursday 1/1
1.8 ft above normal (7.66 ft MLLW) at 9:34 AM Friday 1/2
1.8 ft above normal (7.63 ft MLLW) at 10:26 AM Saturday 1/3
1.6 ft above normal (7.42 ft MLLW) at 11:18 AM Sunday 1/4
These predictions include 0.5 feet of storm surge that will
enhance the astronomical tide and flooding threat. High tide
varies up to 90 minutes earlier or later along the Pacific
Coast and through the San Francisco Bay, respectively.

Information:
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.
Dense Fog Advisory DENSE FOG ADVISORY  
Los Angeles County

  Effective: Mon, 12/29 9:51pm Severity:  Moderate 
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 9:00am Certainty: Likely

Areas Affected: North Bay Interior Valleys
 
Alert Details:
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Cold Weather Advisory, cold conditions
with temperatures as low as 36 expected.

* WHERE...North Bay Interior Valleys.

* WHEN...For the Dense Fog Advisory, until 10 AM PST Tuesday. For the
Cold Weather Advisory, from 1 AM to 9 AM PST Tuesday.

* IMPACTS...Cold conditions will be hazardous to sensitive
populations such as unhoused individuals. Prolonged exposure to the
cold conditions will lead to hypothermia for people, pets, and
livestock. Cold conditions may damage or kill sensitive crops,
plants, and vegetation if appropriate precautions are not taken.
Low visibility could make driving conditions hazardous.

Information:
Ensure portable heaters are working properly and are used correctly
to avoid sparking a fire indoors. Do not use generators or grills
inside as carbon monoxide poisoning can result.

Check with your local, city, or county officials for information on
available warming centers.

Be sure to dress in layers if outdoors. Make sure that pets and
livestock have adequate food, unfrozen water, and warmth. Cover or
tend to sensitive crops, plants, and vegetation.

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

If commuting, allow extra drive time to reach your destination
safely.
Dense Fog Advisory DENSE FOG ADVISORY  
Marin County

  Effective: Mon, 12/29 9:51pm Severity:  Moderate 
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 9:00am Certainty: Likely

Areas Affected: North Bay Interior Valleys
 
Alert Details:
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Cold Weather Advisory, cold conditions
with temperatures as low as 36 expected.

* WHERE...North Bay Interior Valleys.

* WHEN...For the Dense Fog Advisory, until 10 AM PST Tuesday. For the
Cold Weather Advisory, from 1 AM to 9 AM PST Tuesday.

* IMPACTS...Cold conditions will be hazardous to sensitive
populations such as unhoused individuals. Prolonged exposure to the
cold conditions will lead to hypothermia for people, pets, and
livestock. Cold conditions may damage or kill sensitive crops,
plants, and vegetation if appropriate precautions are not taken.
Low visibility could make driving conditions hazardous.

Information:
Ensure portable heaters are working properly and are used correctly
to avoid sparking a fire indoors. Do not use generators or grills
inside as carbon monoxide poisoning can result.

Check with your local, city, or county officials for information on
available warming centers.

Be sure to dress in layers if outdoors. Make sure that pets and
livestock have adequate food, unfrozen water, and warmth. Cover or
tend to sensitive crops, plants, and vegetation.

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

If commuting, allow extra drive time to reach your destination
safely.
Cold Weather Advisory COLD WEATHER ADVISORY  
Los Angeles County

  Effective: Mon, 12/29 9:51pm Severity:  Moderate 
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 9:00am Certainty: Likely

Areas Affected: North Bay Interior Valleys
 
Alert Details:
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Cold Weather Advisory, cold conditions
with temperatures as low as 36 expected.

* WHERE...North Bay Interior Valleys.

* WHEN...For the Dense Fog Advisory, until 10 AM PST Tuesday. For the
Cold Weather Advisory, from 1 AM to 9 AM PST Tuesday.

* IMPACTS...Cold conditions will be hazardous to sensitive
populations such as unhoused individuals. Prolonged exposure to the
cold conditions will lead to hypothermia for people, pets, and
livestock. Cold conditions may damage or kill sensitive crops,
plants, and vegetation if appropriate precautions are not taken.
Low visibility could make driving conditions hazardous.

Information:
Ensure portable heaters are working properly and are used correctly
to avoid sparking a fire indoors. Do not use generators or grills
inside as carbon monoxide poisoning can result.

Check with your local, city, or county officials for information on
available warming centers.

Be sure to dress in layers if outdoors. Make sure that pets and
livestock have adequate food, unfrozen water, and warmth. Cover or
tend to sensitive crops, plants, and vegetation.

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

If commuting, allow extra drive time to reach your destination
safely.
Cold Weather Advisory COLD WEATHER ADVISORY  
Marin County

  Effective: Mon, 12/29 9:51pm Severity:  Moderate 
  Updated: December 30, 2025 12:16 am Urgency: Expected
  Expires: Tue, 12/30 9:00am Certainty: Likely

Areas Affected: North Bay Interior Valleys
 
Alert Details:
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Cold Weather Advisory, cold conditions
with temperatures as low as 36 expected.

* WHERE...North Bay Interior Valleys.

* WHEN...For the Dense Fog Advisory, until 10 AM PST Tuesday. For the
Cold Weather Advisory, from 1 AM to 9 AM PST Tuesday.

* IMPACTS...Cold conditions will be hazardous to sensitive
populations such as unhoused individuals. Prolonged exposure to the
cold conditions will lead to hypothermia for people, pets, and
livestock. Cold conditions may damage or kill sensitive crops,
plants, and vegetation if appropriate precautions are not taken.
Low visibility could make driving conditions hazardous.

Information:
Ensure portable heaters are working properly and are used correctly
to avoid sparking a fire indoors. Do not use generators or grills
inside as carbon monoxide poisoning can result.

Check with your local, city, or county officials for information on
available warming centers.

Be sure to dress in layers if outdoors. Make sure that pets and
livestock have adequate food, unfrozen water, and warmth. Cover or
tend to sensitive crops, plants, and vegetation.

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

If commuting, allow extra drive time to reach your destination
safely.