Multiple accidents occurred, blamed on flooding. Standing water caught some drivers off-guard.
Hitting a patch of standing water at freeway speeds can cause a serious accident.
A minivan was going northbound on Interstate 680 in Milpitas around 11:00 a.m. when the driver lost control, and the vehicle overturned. Fortunately, two CHP officers were driving southbound right after the accident.
"The driver said that there was a large puddle in front of him, and he realized the car was braking and at the same time he just didn't have enough time to stop. He hit the curb and overturned in the exit lane here," said CHP officer Andrea Basile.
RELATED: Strong storm brings flooded roadways to Bay Area
The driver was wearing his seatbelt and was not injured. However, he was trapped inside, and a fire crew had to extract him.
Flood water also contributed to a single vehicle spin-out on Highway 237 at Great America Parkway in San Jose earlier Thursday morning. It happened at an on-ramp, and the driver may not have seen the puddle until it was too late. The driver and a passenger were not hurt, but their car had front-end damage.
Also in the South Bay, drivers on Highway 680 plowed into a huge pond spread over two lanes. Poor visibility prevented them from taking evasive action as they went northbound, passing underneath the Alum Rock overpass. It clearly took them by surprise. Fortunately, there were no collisions.
Other road hazards during storms are potholes and cracks in pavement that open up in heavy rain.
City of San Jose road crews were out doing asphalt patches to address those problems. The Highway Patrol says it's important for drivers to slow down in heavy rain storms .
"You definitely need to slow down, realize the visibility is going to be lower and the roads are going to be wet," said CHP officer Basile. "Make sure you're not tailgating, wear your seatbelt and looking far ahead in front of you and just driving slower than you normally would."
You can track the rain where you live with our live radar here.