The following events were reported: Debris Flow, Flash Flood, Flood. These occurred near station USW00023234, approximately 22.857 km away, between 2014-12-11 04:30:00 and 2014-12-11 16:53:00. The flood was caused by Heavy Rain. Thankfully, no injuries or fatalities were reported. The events caused property damage valued at 2551500.0 and crop damage of 0.0. Episode Narrative: An Atmospheric River event brought heavy rain and gusty winds with a strong winter storm that impacted the Bay Area for several days in mid-December. Cyclogenesis occurred with a 979 mb low forming off the Northern California coast. On December 11, the intense surface low moved up the coast and drug a narrow cold frontal rainband (NCFR) through the Bay Area that morning and early afternoon. NCFRs are rapidly moving fronts that are notorious for intense rainfall and gusty winds despite having limited instability. ||The NCFR wasn't a major wind producer, but the rainfall rates were impressive. Instantaneous rainfall rates of 1.5-2 inches/hr were reported. Observational data from the Big Sur Coast were also impressive with Big Sur receiving 4.43 in 2 hours and Flores Camp receiving 3 in 1 hour. It wasn't so much the total amount of rainfall for many locations, but the intensity and how much was received in a short amount of time. ||Many locations around the entire Bay Area had flooding: urban flooding of streets and highways, flooding of creeks and even one large river in the North Bay. Eventually the NCFR slowed around the Big Sur Coast. The stalling was likely due to another 'wave' in the atmosphere, farther to the southwest, riding along the boundary. The end result was to have the weakened NCFR lift back northward, almost like a quasi-warm front, producing another round of moderate to locally heavy rainfall around the Bay Area, compounding flooding concerns. ||In addition to the impressive rainfall, winds also became a problem for the water soaked ground, drought stressed trees and diseased trees. Peak winds occurred over the higher terrain with the Lick Observatory reporting 83 mph. Most low elevation areas saw much lower wind speeds.||Lastly, the intense winds over the coastal waters helped to generate a fresh swell that produced very dangerous surf with large breaking waves. The Big Sur Coast buoy reported a peak wave of 19.7 feet.||The event was followed by several weaker storm systems that week that brought additional rainfall, continued flooding and mudslide concerns to the area. An Atmospheric River event brought heavy rain and gusty winds with a strong winter storm that impacted the Bay Area for several days in mid-December. Event Narrative: Significant flash flooding on Interstate 280 was reported by the public. This coincided with a nearby observation of 0.90 of rainfall in 30 minutes at San Bruno Mountain. Traffic was significantly impacted and slowed or stopped during the height of morning rush hour. California Highway Patrol observed 18 inches of water on roadway on WestBound Interstate 580 to Eastbound Route 24. Public reports water covering roadway and parking lots along San Pedro Creek. Flooding on all lanes of Northbound US-101 at Lucky Drive. Multiple lanes of CA-92 blocked due to flooding, west of Interstate 880. Ashby Avenue Railway underpass near I-80 is flooded. Three cars are stranded and floating in floodwaters. Highway 1 flooded and closed from Panoramic Highway to Muir Woods Road. Heavy rain caused flooding of several trailer parks in Redwood City. The combination of standing water and a local creek flooding resulted in the need for residents to be evacuated from the Le Mar Trailer Park and RC Mobile Home Park on E Bayshore in Redwood City. 50 mobile homes were evacuated and residents were sent to shelters. A slide under sixty feet of Highway 1 near Muir Beach resulted in a full closure of the road which is expected to last for several months. A significant mudslide occurred along Tennessee Valley Road. San Bruno BART station closed during rush hour commute due to flooding of station from heavy rain.