Winter Storm Update - Saturday, December 7

12/7/2019 - 9:45 am

The San Francisco Bay Area is under a Flash Flood Watch from 10 AM this morning through 10 PM this evening.

Today, showers will continue as the storm moves southward through our area. Although the storm front has weakened considerably, we can expect rain and the possibility of thunderstorms this afternoon. Forecasters predict showers will continue through the evening and linger into Sunday. Winds remain gusty over the higher terrain, but are decreasing.

There have been no reports of significant impacts in Mill Valley. However, conditions can change and we ask community members to take some time to review the information below and always be prepared and aware in storm conditions.

Latest weather conditions: Latest Forecast.

Special Advisory to Residents in Low-Lying Areas

Mill Valley has had a history of experiencing localized flooding in low-lying areas. If you live in an area that has a history of flooding, it is highly recommended that you be proactive now and stay alert.  

  • Monitor creek and tide levels. 
  • Consider moving personal belongings to higher ground, including vehicles.
  • Avoid walking in flood waters as this could pose a threat of injury or death.  
  • If present, avoid down power lines.  
  • If conditions worsen, the Fire Department recommends you shelter in place.

The next upcoming high tides 5 feet and higher will take place:

12/6/2019at 7:41 AM: 5.19 feet
12/7/2019 at 8:11 AM: 5.41 feet
12/8/2019 at 8:41 AM: 5.63 feet
12/9/2019 at 9:11 AM: 5.84 feet
12/10/2019 at 9:43 AM: 6.01 feet
12/11/2019 at 10:16 AM: 6.15 feet
12/12/2019 at 10:53 AM: 6.23 feet




Secure garbage cans, lawn furniture or anything that could become airborne and cause damage. Clean out gutters, storm drains, etc. (keeping drains clear of trash, leaves and branches) so rainwaters can easily flow, reducing possible flooding and ponding.

Commuters who travel in areas with a history of flooding are advised to monitor high tides. Check prior to your trip to anticipate traffic conditions. Road closures are often posted by the Mill Valley Police Department on Twitter.

Please be advised to keep out of creeks and waterways during the storm. 

Power Outages
Residents are advised of possible downed trees and power lines. Power outages are likely in the Bay Area.

Here are some tips:

  • Check to make sure you have batteries, fully charged back-up battery packs for your devices, and a battery powered radio.
  • Recharge your laptop computer, cell phone, and other mobile devices as a precaution against a power outage.
  • Have flashlights with extra batteries for every household member.
  • Freeze water bottles or bags of water for food storage if the power goes out.
  • Have enough nonperishable food and water.
  • Make sure you can open your garage door if the power goes out.

If the power goes out:

  • Do not call 9-1-1 unless you are having a life-threatening emergency.
  • Call (800) 743-5000 or check the PG&E Outage Map for updates. 
  • Monitor local news for information and updates - local AM radio stations are a good source of information
  • Keep freezers and refrigerators closed.
  • Only use generators outdoors and away from windows.
  • Do not use a gas stove to heat your home.
  • Disconnect appliances and electronics to avoid damage from electrical surges.
  • Have alternate plans for refrigerating medicines or using power-dependent medical devices.
  • If safe, go to an alternate location for heat. 
  • Check on your neighbors.

If you see a downed power line call 911 immediately. For more safety information about downed power lines click here.

Traffic & Road Closures
Flooding or fallen trees may cause traffic back-ups and road closures. Road closures will be posted on our homepage at as they are reported. Check for updates on traffic before your trip. 

Drive with Caution: When driving in the rain, use extra caution and always have your headlights on. Remember, if you turn on your windshield wipers, turn on your headlights. Please obey the speed limits and follow other traffic at a safe distance.

Stock up on Sandbags
We urge residents to take preparedness measures by seeking sand and sandbags should they need them. Sand and bags can be purchased at local hardware stores. Watch a video on how to fill and place sandbags.

City Supplied Sandbags (unfilled)
Residents or business owners may also pick up unfilled sand bags at:

Mill Valley Main Fire Station 7
(Public Safety Building), 1 Hamilton Drive.
Limit of 10 sandbags per household or business.

Sand may be located at the following locations:*

  1. Hauke Park parking lot next to Public Safety Building, 1 Hamilton Drive
  2. Thalia parking lot at Boyle Parkoff of East Blithedale Avenue
  3. Parking area on Molino Ave., behind Old Mill Park (approximately 100' yards east of Molino Avenue/Cascade Way)

*These locations have limited stockpiles of sand for emergency use during the rainy season. To use these stockpiles,you must supply your own labor, shovels and support.

Please note that the safety of Mill Valley citizens is the first priority of City work crews, and that replenishing the sand pile and bags may become a lower priority during a storm event. If you have questions or comments please call Department of Public Works at 388-4033 or the Fire Department at 389-4130. 

High tides, combined with high run-off sometimes leads to flooding on lower Miller Avenue and Camino Alto, as well as the Redwood Hwy Frontage Road. 

Please click here for High Tide information.

How to stay informed during winter storms? 

Sign up for alerts and warnings. We will post regular updates to the website.

Be prepared
The City of Mill Valley strongly encourages businesses and residents to prepare for the upcoming rain and potential flooding. 

Click here for Storm Preparation information.