11:49 AM: A tornado warning for San Mateo County issued by the National Weather Service expired at 11:30 a.m. with no report of damage, a meteorologist with the weather service said late this morning.
The warning was issued at about 11 a.m. for most of the county as the weather service’s radar system picked up signs of a severe thunderstorm and possible tornado approaching the coast, meteorologist Steve Anderson said.
Winds of 30 to 40 mph, a downpour of rain, and pea-sized hail were reported, but not a tornado, Anderson said.
The heavy part of the storm has passed through the Peninsula, and “once it got over the Bay, it decreased in intensity rapidly,” he said.
The storm was moving through Alameda and Contra Costa counties as of 11:40 a.m., he said.
11:33 AM: The National Weather Service issued a tornado warning this morning for San Mateo County due to a severe thunderstorm in the area, but while the warning expired at 11:30, officials still urge caution for area residents.
The warning is for the cities of San Mateo, San Carlos, Redwood City, Millbrae, Foster City, Burlingame, Belmont, Hillsborough and Half Moon Bay, according to the weather service. According to NBC 11 broadcast, the storm system is expected to continue to move east, hitting Oakland at 11:35, Alamo at 12:03, San Ramon at 12:04, amd Antioch at 12:31.
The weather service issued the warning at 10:58 a.m. and set it to “expire at 11:30. A spokesperson said, however, that the area still has an “unsteady air mass” that could lead to “dangerous conditions.
People caught outside should seek shelter in a nearby reinforced building, or at last resort, seek shelter in a culvert.
Eve Batey contributed to this report from Dan McMenamin, Bay City News