San Mateo and Santa Clara counties are the focus of a severe thunderstorm warning issued at 6:35 p.m. on Thursday by the National Weather Service. The warning is in effect until 7 p.m.
Residents should be prepared for wind gusts of up to 60 mph.
“At 6:35 p.m., a severe thunderstorm was located over Stanford, or over Palo Alto, moving northeast at 50 mph,” according to the NWS San Francisco CA. “Expect damage to roofs, siding, and trees.”
Locations impacted by the warning include Redwood City, Palo Alto, Menlo Park, East Palo Alto, Los Altos Hills, Atherton, Woodside, Stanford, North Fair Oaks, Portola Valley and West Menlo Park.
The NWS said, “Wind damage with this storm will occur before any rain or lightning. Do not wait for the sound of thunder before taking cover. Seek shelter immediately inside a sturdy structure and stay away from windows.”
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:
Staying safe as lightning approaches: Expert advice
Each year, lightning strikes the United States approximately 25 million times, mostly during the summer. It claims the lives of about 20 people annually, according to the NWS. The threat of lightning becomes more pronounced as thunderstorms draw nearer, peaking when the storm is directly overhead and gradually waning as it moves away.
To ensure your safety during a thunderstorm, consider the following recommendations:
Lightning safety plan:
- When venturing outdoors, it’s crucial to have a lightning safety plan in place.
- Stay vigilant by monitoring the sky for ominous signs and listening for the telltale sound of thunder. If thunder is audible, it’s a clear indication of nearby lightning.
- Seek a safe place to shelter, preferably indoors.
Indoors safety measures:
- Once you’re indoors, avoid using corded phones, electrical devices, plumbing fixtures, and stay away from windows and doors.
- Lightning can follow conductive pathways, and these precautions reduce the risk of electrical surges.
Wait for the all-clear:
- After the last lightning strike or thunderclap, wait at least 30 minutes before resuming outdoor activities.
- Lightning can strike even when a storm has seemingly passed, so exercise caution.
When indoor shelter isn’t available:
If you find yourself outdoors with no access to indoor shelter during a thunderstorm, take these steps to maximize your safety:
- Avoid open fields, hilltops, or ridge crests, which expose you to greater lightning risk.
- Steer clear of tall, isolated trees and other prominent objects. In forested areas, stay close to lower stands of trees.
- If you’re in a group, ensure that individuals are spaced out to prevent lightning current from transferring between people.
- Camping in an open setting during a thunderstorm is strongly discouraged. If you have no alternative, set up camp in a valley, ravine, or other low-lying areas. It’s crucial to note that a tent provides no protection against lightning.
- Do not approach water bodies, wet objects, or metal items. While water and metal don’t attract lightning, they conduct electricity effectively and can pose significant risks.
In summary, when facing the threat of lightning, vigilance and preparedness are your best allies. By following these guidelines, you can significantly reduce the chances of lightning-related accidents and prioritize your safety.
Rainy roadways ahead: Essential safety tips for heavy rain
Heavy rainfall may lead to flooding if prolonged or if there is excessive runoff. Excessive runoff can be a result of saturated ground and/or rainfall intensity. Follow these recommendations from the NWS to stay safe in heavy rain:
Beware of swollen waterways:
During heavy rain, avoid parking or walking near culverts or drainage ditches, where swift-moving water can pose a serious risk.
Maintain safe driving distances:
Adhere to the two-second rule for maintaining a safe following distance behind the vehicle in front of you. In heavy rain, allow an additional two seconds of distance to compensate for reduced traction and braking effectiveness.
Slow down and drive with care:
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 to minimize the risk of hydroplaning. Outer lanes are more prone to accumulating water.
Prioritize visibility
Enhance your visibility in heavy rain by turning on your headlights. Watch out for vehicles in blind spots, as rain-smeared windows can obscure them.
Watch out for slippery roads:
The initial half-hour of rain is when roads are slickest due to a mixture 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 limits your sight, pull over and wait for conditions to improve. Seek refuge at rest areas or protected spots.
When stopping by the roadside is your only option, position your vehicle as far off the road as possible, ideally beyond guardrails. Keep your headlights on and activate emergency flashers to alert other drivers of your position.
In the face of heavy rain, these precautions can make a significant difference in ensuring your safety on the road. Remember to stay informed about weather conditions and heed guidance from local authorities for a secure journey.
For more weather alerts in the Bay Area, visit Weather Advisories