After an exceptional period with little to no rainfall, much needed rain fell across the Bay Area February 6th through the 9th. In fact, the lack of rainfall lead to the largest deficit of rain in recorded history for the Bay Area.
The first storm system began to develop on Wednesday (Feb 5) as a shortwave trough moved toward the West Coast. The shortwave trough deepened through the day allowing for a surface low to develop Wednesday Night off the coast. The resulting surface low increased low level warm advection and enhanced orographic lift along the coastal mountains. Rainfall amounts with this system varied from just over one half inch to a little more than two inches.
The second and much stronger storm system brought impressive rainfall totals to the coastal mountains, especially the North Bay. The bulk of the rainfall occurred Friday night through Saturday. Several key factors led to the impressive rainfall: middle level flow perpendicular to the coast , orographic lift along the coastal mountains, but most prominently was a plume of very moist air streaming in from off the Pacific Ocean (an Atmospheric River).  As the moisture plume moved into the region rain began to overspread the North Bay Thursday night into Friday morning. Over the next 24 hours the main push of higher precipitable water moved over the Bay Area leading to the onset of steadier and at times heavy rainfall. By Sunday, rain began to diminish with off and on showers through the day.
Despite the long preceding period of dry weather, the several days of persistent rainfall resulted in some flooding and even landslides in parts of the Bay Area. Conditions were so bad on a stretch of the Ft Ross-Cazadero Highway that part of it washed away.

Flash Flood in SONOMA, CALIFORNIA
From 08-FEB-14 14:31:00 to 08-FEB-14 14:31:00 (PST-8)
Location: COTATI
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Vehicle stuck in mud and water, party had to be rescued as they were unable to exit the vehicle.

Flood in SONOMA, CALIFORNIA
From 09-FEB-14 13:10:00 to 09-FEB-14 13:10:00 (PST-8)
Location: MOLINO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

SUV stuck in standing water, reported to be halfway up the door.

Flood in MARIN, CALIFORNIA
From 09-FEB-14 11:44:00 to 09-FEB-14 11:44:00 (PST-8)
Location: MILL VLY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Flooded streets reported around the 2 AM Club.

Flood in SONOMA, CALIFORNIA
From 09-FEB-14 12:04:00 to 09-FEB-14 12:04:00 (PST-8)
Location: SCHELLVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Flooding closed State Route 121 at Highway 12 near Sonoma.

Heavy Rain in SAN FRANCISCO, CALIFORNIA
From 08-FEB-14 06:20:00 to 08-FEB-14 06:20:00 (PST-8)
Location: SAN FRANCISCO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported this as a 24 Hour Rainfall Total.

Heavy Rain in SAN FRANCISCO, CALIFORNIA
From 08-FEB-14 08:13:00 to 08-FEB-14 08:13:00 (PST-8)
Location: SAN FRANCISCO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported this as a 24 hour rainfall total.

Heavy Rain in SONOMA, CALIFORNIA
From 08-FEB-14 10:30:00 to 08-FEB-14 10:30:00 (PST-8)
Location: WILFRED
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall total reported since 10 AM yesterday with an additional 0.54 inches of rainfall since 10 AM today.

Heavy Rain in SAN FRANCISCO, CALIFORNIA
From 09-FEB-14 06:20:00 to 09-FEB-14 06:20:00 (PST-8)
Location: SAN FRANCISCO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported this as a 24 hour rainfall total.

Heavy Rain in SANTA CLARA, CALIFORNIA
From 09-FEB-14 09:24:00 to 09-FEB-14 09:24:00 (PST-8)
Location: BURBANK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported this as a 24 hour rainfall total.