Flash flood warning in place for San Mateo County until early Thursday morning – urgent action advised
San Francisco and San Mateo counties were placed under an updated flash flood warning by the National Weather Service on Thursday at 2:56 a.m. The warning is in effect until 6 a.m.
“At 2:56 a.m., The public reported heavy rain and flooding across the warned area. Between 0.5 and 1 inch of rain has fallen. Flash flooding is already occurring,” the NWS San Francisco CA said. “Life threatening flash flooding of creeks and streams, urban areas, highways, streets and underpasses.”
Locations impacted by the warning include San Francisco, Daly City, South San Francisco, San Bruno, Pacifica, Millbrae, Brisbane, Colma and Broadmoor.
The NWS said, “Turn around, don’t drown when encountering flooded roads. Most flood deaths occur in vehicles. Be especially cautious at night when it is harder to recognize the dangers of flooding. Be aware of your surroundings and do not drive on flooded roads.”
How to use a sandbag and where to get sandbags in your area:
Follow these instructions on how to use sandbags and other flood preparation tips to protect your home, and click on the links below to get sandbags in your county:
Where to get sandbags in San Mateo County
Where to get sandbags in Alameda County
Where to get sandbags in Santa Clara County
Emergency alerts in the San Francisco Bay Area
All enabled mobile phones in the area will receive emergency alerts for “considerable or catastrophic” hazards. To monitor other local risk, residents are advised to sign up for county alert systems and to monitor agencies’ social media. Follow these instructions to enable your phone to receive Wireless Emergency Alerts (WEAs). To receive local alerts in the Bay Area, visit each county’s website:
Your guide to weather alerts: advisories, watches, and warnings
- Flash flood warning: Take action!
A flash flood warning is issued when a flash flood is imminent or occurring. If you are in a flood-prone area, move immediately to high ground. A flash flood is a sudden violent flood that can take from minutes to hours to develop. It is even possible to experience a flash flood in areas not immediately receiving rain.
- Flood warning: Take action!
A flood warning is declared when flooding is on the verge of happening or is already underway.
- Flood advisory: Be aware:
A flood advisory is issued when flooding is not expected to be bad enough to issue a warning. However, it may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.
- Flood watch: Be prepared:
A flood watch is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.
Weathering the storm: Flood safety guidelines from the NWS
Floods can pose a significant threat, especially if you live in a flood-prone area or find yourself camping in a low-lying region. To ensure your safety, the NWS offers essential flood safety guidelines:
Seek higher ground:
If you’re in a flood-prone area, or if you’re camping in a low-lying spot, move to higher ground as a first step.
Follow evacuation orders:
If local authorities issue an evacuation order, heed it promptly. Prior to leaving, secure your home by locking it.
Disconnect utilities and appliances:
If time allows, disconnect your utilities and appliances. This reduces the risk of electrical hazards during flooding.
Steer clear of flooded basements and submerged areas:
Steer clear of basements or rooms where water has submerged electrical outlets or cords. This helps prevent electrical accidents.
Swift evacuation for your safety:
If you notice sparks or hear buzzing, crackling, snapping, or popping noises, evacuate immediately. Avoid any water that may be charged with electricity.
Refrain from walking in floodwaters:
Never attempt to walk through floodwaters, even if they appear shallow. Just 6 inches of fast-moving water can forcefully sweep you off your feet.
Seek high ground if trapped:
Should you become trapped by moving water, reach the highest point possible and dial 911 to contact emergency services.
During heavy rainfall, the risk of flooding is heightened, especially in low-lying and flood-prone regions. Always remember never to drive through water on the road, no matter how shallow it appears. According to the NWS, as little as 12 inches of rapidly flowing water can carry away most vehicles. Stay safe by being prepared and informed.
Rainy roadways ahead: Essential safety tips for heavy rain
Rain can turn roads into hazards. Stay informed and follow these tips from the NWS to ensure safety during heavy rainfall:
Beware of swollen waterways:
In heavy rain, refrain from parking or walking near culverts or drainage ditches, where swift-moving water can pose a grave danger.
Maintain safe driving distances:
The two-second rule for following distance is your ally in heavy rain. Extend it to four seconds to ensure safe spacing in adverse conditions.
Slow down and stay cautious:
On wet roads, slowing down is paramount. Gradually ease off the accelerator and avoid abrupt braking to prevent skidding.
Choose your lane wisely:
Stick to the middle lanes on multi-lane roads to minimize the risk of hydroplaning, as water tends to accumulate in outer lanes.
Visibility matters:
Enhance your visibility in heavy rain by activating your headlights. Be particularly vigilant for vehicles in blind spots, as rain-smeared windows can obscure them.
Watch out for slippery roads:
The first half-hour of rain is when roads are slickest due to a mix of rain, grime, and oil. Exercise heightened caution during this period.
Keep a safe distance from large vehicles:
Large trucks and buses can reduce your visibility with tire spray. Avoid tailgating and pass with caution.
Mind your windshield wipers:
- Overloaded wiper blades can hinder visibility. If rain severely impairs your vision, pull over and wait for conditions to improve. Seek refuge at rest areas or sheltered spots.
- If the roadside is your only option, pull off as far as possible, preferably past the end of a guard rail, and wait until the storm passes. Keep your headlights on and turn on emergency flashers to alert other drivers of your position.
By following these safety measures, you can significantly reduce risks and ensure your well-being when heavy rain pours down. Stay informed about weather conditions and heed advice from local authorities to make your journey safe and sound.
For more weather alerts in the Bay Area, visit Weather Advisories