March 8, 2023
  • Watch for Debris
    High winds are expected Thursday afternoon through Friday across San Mateo County. A January storm with rain and high winds led to this sign on Highway 1 near Half Moon Bay.

    Redwood City – Heavy rain and strong winds are expected to strike San Mateo County by mid-day Thursday, bringing the threat of flooding, mudslides and falling trees and limbs through the weekend.

    The County of San Mateo Department of Emergency Management cautions residents to  prepare for severe weather, sign up for emergency alerts, monitor weather forecasts and avoid driving during heavy rains.

    “The soils are already saturated from the rains we had in January and February and now we’re going to put more water on top of that,” said Brian Garcia, a meteorologist with the National Weather Service. “Soils are already oozing out water so that is going to result in flooding and/or mud slides.”

    The County today activated its Emergency Operations Center to coordinate local response to a storm the National Weather Service said is likely to bring sustained winds of 25 to 35 mph with gusts in the higher elevations possibly reaching 70 mph.

    San Mateo County is under both a wind advisory and a flood watch from 1 p.m. Thursday through 4 p.m. Friday. More rain – and the risk of flooding and slides – is expected through the weekend and into next week.

    To help you and your family prepare, the County offers the following recommendations:

    Get connected
    Check the following to stay up to date on storm-related information and local resources:

    Sign up for SMC Alert, which sends emergency messages to email, cell phones and other devices and landline telephones

    Get news and information on social media:

    Find out about road conditions, power outages, park closures and more:

    Stay off the roads if you can
    If you must travel, do not drive into flooded areas. A foot of water can float many cars, and two feet of rushing water can carry away most vehicles including sport utility vehicles and pick-ups.

    Keep an extra flashlight, food, and water in your vehicle in case of an emergency. Here are preparedness tips from

    Find sandbag locations
    The County is offering sandbags to residents and businesses in the unincorporated areas. Here is a map and a list of pick-up locations in the unincorporated areas, plus a list of locations from cities.

    Be sure to call ahead to confirm availability and allowed quantities. Note that sandbags can be reused.

    Know your zone
    Emergency managers have carved the Peninsula into more than 300 zones on an online, publicly available map supported by Zonehaven, a California-based company under contract with the County of San Mateo.

    Each zone is assigned a short code. All residents can enter an address to find their zone.

    In an emergency, first responders will issue evacuation or other orders and advisories based on the zones. This information will be pushed out via the news media, social media such as Twitter, emergency alert notifications and other platforms.

    Call 9-1-1 only in emergencies
    An emergency is any serious medical problem (chest pain, seizure, bleeding), any type of fire (business, car, building), any life-threatening situation (fights, person with weapons) or to report crimes in progress.

    Do not call 911 for a non-emergency.

    Connect with your city
    Nine out of 10 San Mateo County residents live in an incorporated city or town (Daly City, San Mateo, Redwood City, for instance).

    Find your city’s website and check it out for more localized information.

    Media Contact

    Michelle Durand
    Chief Communications Officer