A winter storm packing heavy rain and strong winds is expected to hit San Mateo County over the next few days. Below are some tips on how to keep you and your family safe.
For the County, thunderstorms and wind gusts of up to 55 mph are possible throughout the day with periods of intense rainfall expected this evening, according to the National Weather Service. On Wednesday, a strong storm system will move over the North Coast. Rain and mountain snow will become heavy at times across the North and will push into central and southern portions of the area during the late morning/afternoon. Strong southerly winds gusting to 40-55 mph are expected along the North Coast, over higher Bay Area terrain, over the Central Coast, through the Delta, portions of the Valley, and adjacent foothills, with gusts up to 65+ possible over the highest terrain. Winds will shift to the southwest and then the west as the cold front sweeps across the region this afternoon and evening. Heavy rain and mountain snow will fall, and rainfall totals of 1-3” are expected along the coast and across higher elevation and 0.25”-1” in the interior. Snow levels are starting at 4000-6000 feet North to South this morning, lowering through the day resulting in periods of heavy mountain snow. Additionally, with the arrival of colder air aloft behind the front, there is a slight chance of thunderstorms this afternoon and evening along the coast and interior valleys. Winter Storm Warnings as well as winter weather/wind advisories issued by the National Weather Service are in effect for many locations, details can be found here: NWS Winter Watches/Warnings.
On Thursday, the cold front is expected to exit the South. Widespread showers activity and mountain snow showers are expected to continue across the area through tomorrow evening, tapering off late, along with gusty northwesterly winds in the South and across higher elevation in the North. Snow levels are expected to lower to around 2000-4000 feet North to South late tonight into tomorrow morning resulting in potential for low elevation snow. There is also chance of isolated thunderstorms to develop tomorrow afternoon and evening across Central Valley.
The next weather system arrives overnight Thur-Fri across the North and sweeps across the area Friday with more rain, mountain snow and gusty winds. Although not expected to be as strong and the previous weather system, more adverse weather is anticipated with additional rainfall amounts of 0.50-1.50” possible, combined with southwest to west winds gusting to 40-45 mph over higher terrain. Snow levels are expected to remain around 2000-3000 feet Friday morning, with additional low elevation snowfall accumulations of several inches possible. Showers might linger across higher terrain and across the North Saturday, while the South will remain mostly dry Saturday.
“Expect rain rates up to 0.50 (of an inch) per hour with the main front,” the weather service posted in its morning forecast. Up to 4 inches of rain could drench coastal areas by the end of the week.
Residents are encouraged to sign up for emergency alerts at SMC Alert. This is the County’s primary alert and warning system used to contact you during urgent or emergency situations which may include life safety, fire, weather, accidents involving utilities or roadways or disaster notifications.
Prepare your residence
- Secure outdoor furniture
- Keep emergency supplies handy
- Check on neighbors
Heavy rains can cause flooding and erosion and sweep away topsoil, mud, plant material and debris off.
To help prevent damage, Atherton residents may pick up sandbags free of charge at the back parking lot at Holbrook Palmer Park. The County also provides a list of sandbag locations for residents within cities. Be sure to verify the information before heading out. Be prepared to assemble and load the sandbags yourself. Most sandbag stations require assembly of the sandbags.
Drivers should avoid flooded roadways. Be careful on the roads
- Reduce speed - give yourself 5-10mph buffer below limits
- Turn on headlights - improves visibility
- Double your following distance (at least 4-5 seconds)
- Avoid puddles that hide potholes
- Never drive through flooded roads
- A mere 6 inches of fast-moving flood water can knock over an adult. It takes just 12 inches of rushing water to carry away most cars and just 2 feet of rushing water can carry away SUVs and trucks.
- Postpone unnecessary travel during the heaviest rainfall
- If hydroplaning: ease off gas, don't brake suddenly, steer straight
Resources:
Stay Informed: Sign-Up for the County of San Mateo's Alert Notifications: https://www.smcgov.org/ceo/smc-alert
Police Non-Emergency Line: 650-688-6500
Sign-Up for the Town’s News Flash for Important Updates: https://www.ci.atherton.ca.us/list.aspx
Alert Center: When active, the Alert Center will appear as a banner across the top of the Town's website.
Report non-emergency concerns to the Town: https://www.ci.atherton.ca.us/574/Access-Atherton---Report-A-Concern
County of San Mateo Storm Resources: https://www.smcgov.org/ceo/county-storm-related-emergency-information
During emergencies, 2-1-1 provides incident-specific information in coordination with local emergency services, including support for private property damage and information on road closures and shelters. Contact by phone by dialing 2-1-1 or 800-273-6222 or text your zip code to 898211.
Atherton Channel Monitoring Station:
OneShoreline - San Mateo County Flood and Sea Level Rise Resiliency District