A second round of heavy rain should move through the Bay Area on Tuesday morning, making for a wet start to the day. The afternoon will feature scattered showers, more downpours and perhaps even a rumble of thunder before the storm’s focus shifts east to the Central Valley and Sierra Nevada.
Monday’s rain came with the passage of a cold front. Tuesday’s rain comes from the same weather system — an upper-level low still parked off the Northern California coast — but the character will shift from steady frontal rain to heavier bursts.
The timing of the morning round is relatively uncertain. The commute should start dry for most of the Bay Area, but expect widespread rain across San Francisco, the Peninsula, Oakland and Berkeley from about 9 a.m. through 1 p.m. The North Bay will see showers continuing from the overnight hours through the morning, with amounts tapering by midday. The South Bay and Santa Clara Valley will see lighter and more scattered showers.
Bay Area showers will turn hit-or-miss in the afternoon as the cold core of the upper-level low arrives overhead. The best chances for showers and downpours will be over the Santa Cruz Mountains, the East Bay hills and the North Bay hills, where stronger cells could produce gusty winds, small hail or a rumble of thunder…