North Bay Interior Valleys under Dense Fog Advisory Until Friday Morning
On Friday, the National Weather Service (NWS) in San Francisco, CA, issued a dense fog advisory for the North Bay Interior Valleys, effective until 10 a.m.
Advisory Details
The NWS warns of visibility reduced to one quarter mile or less due to dense fog, which could make driving hazardous.
"Visibility one quarter mile or less in dense fog."
"Low visibility could make driving conditions hazardous," says the NWS.
Drivers are advised to slow down, use headlights, and maintain a safe distance from other vehicles.
Safety Recommendations
- Drive cautiously and reduce speed.
- Use headlights during foggy conditions.
- Keep extra distance ahead to allow for safe stopping.
- Avoid driving if possible until the advisory is lifted.
A dense fog advisory is issued when widespread fog leads to visibility frequently dropping to a quarter mile or less, significantly impacting travel safety.
"A dense fog advisory is issued by your local National Weather Service office when widespread dense fog develops."
Source: The National Weather Service, originally published November 7, 2025 at 1:52 AM.
Summary
The North Bay Interior Valleys will remain under a dense fog advisory until 10 a.m., urging drivers to take extra precaution or avoid travel due to hazardous low visibility conditions.