Strong and gusty west-northwest winds impacted much of the Bay Area resulting in downed trees, downed power lines, toppled scaffolding, and blown over tractor trailers. An unseasonably cold and rapidly developing low pressure system moved through the Bay Area during the afternoon hours of October 27 and the early morning hours of October 28th. As the surface low rapdily deepened a tight pressure gradient developed across the Bay Area, most notably the East Bay. The dropping surface pressures and rather strong onshore pressure gradient helped to produce widespread wind gusts in excess of 35 mph with a few locations over 60 mph. As the strong onshore winds were squeezed through the East Bay hills winds were enhanced knocking over tractor trailers on Altamont Pass.

High Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 27-OCT-13 20:12:00 to 27-OCT-13 20:12:00 (PST-8)
Magnitude: 65.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gusts of 75 MPH measured on a mesonet site in Altamont Pass. Tractor trailers were blown over on the highway through Altamont Pass.

High Wind in MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY INCLUDING PINNACLES NATIONAL PARK, CALIFORNIA
From 27-OCT-13 23:57:00 to 27-OCT-13 23:57:00 (PST-8)
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A wind gust of 69 MPH was measured at the Santa Rita Mesonet Site in San Benito County at an elevation of 5000 feet.

High Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 27-OCT-13 19:45:00 to 27-OCT-13 19:45:00 (PST-8)
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A wind gust of 62 MPH was measured on the Los Vaqueros RAWS at elevation 1100 feet.

High Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 27-OCT-13 23:18:00 to 27-OCT-13 23:18:00 (PST-8)
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A wind gust of 61 MPH was measured on the Calaveras Road RAWS at elevation 1230 feet.

Strong Wind in EAST BAY INTERIOR VALLEYS, CALIFORNIA
From 27-OCT-13 23:00:00 to 27-OCT-13 23:00:00 (PST-8)
Magnitude: 48.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Newspaper

Strong winds blew a tree down on a house in Antioch. The tree branches broke through the roof and into a bedroom where it injured a man by cutting his back.

Strong Wind in SAN FRANCISCO BAY SHORELINE, CALIFORNIA
From 27-OCT-13 23:00:00 to 27-OCT-13 23:00:00 (PST-8)
Magnitude: 39.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Strong winds knocked down scaffolding and metal awnings at the Bay Street Shopping Center in Emeryville.

Strong Wind in SAN FRANCISCO BAY SHORELINE, CALIFORNIA
From 27-OCT-13 21:00:00 to 27-OCT-13 21:00:00 (PST-8)
Magnitude: 39.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Strong Winds blew a large tree branch down onto a fence and into the backyard of a house in Redwood City.

Strong Wind in EAST BAY INTERIOR VALLEYS, CALIFORNIA
From 27-OCT-13 20:45:00 to 27-OCT-13 20:45:00 (PST-8)
Magnitude: 39.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Strong winds resulted in power outages to 3200 customers in Antioch.

Strong Wind in SAN FRANCISCO, CALIFORNIA
From 27-OCT-13 21:00:00 to 27-OCT-13 21:00:00 (PST-8)
Magnitude: 39.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Department of Highways

Public works department in San Francisco responded to three calls for downed trees due to high wind at Van Ness Avenue and Pine Street, Valencia and 20th Street, and Third and 20th Street.