A main thoroughfare through Menlo Park's Belle Haven neighborhood, adjacent to the Meta campus, flooded overnight in one of the Bay Area's first significant flooding events in this storm.

As KTVU reports, residents of the area along Hamilton Avenue in Menlo Park began receiving robocalls about flooding around 4:20 am Wednesday, with cars parked along the street becoming partially submerged in water by daylight.  The flooding was occurring on Hamilton Avenue between Willow Avenue and Henderson Avenue — an area primarily occupied by businesses, but there are a couple dozen residences along the south side of the street.

The exact cause of the flooding was not clear, but the area is near the edge of the Bay, and a tweet from the City of Menlo Park Wednesday morning suggested clogged storm drains may be to blame.

"City and West Bay are working together to clear storm drains and have contacted related agencies to clear the flood," the city said.

All residents and workers were being advised to avoid the area until the flooding clears, and this section of Hamilton Avenue is closed to traffic.

Speaking to KTVU, Menlo Park resident Luis Ibara, who has lived in the area for 25 years, says of the flooding, "This is the worst I've ever seen it."

Flooding was also reported on the 1300 block of Carlton Avenue, which runs parallel to Willow Avenue.

Much of the Bay Area, including the San Francisco Bay shoreline, is under a Flood Watch until Friday due to potential impacts from excessive rainfall.