A very fast moving cold front swept through the San Francisco Bay Area on Saturday evening. It brought heavy rain, gusty winds, and hail to much of the reason - but the big story was the possible tornado touchdowns in the cities of Richmond and Castro Valley. On Sunday afternoon, I drove to each city to investigate the damage.
The damage I saw in Castro Valley was limited to a very small area on Baker Road just south of Castro Valley Boulevard. A 50-ft section of power lines on the west side of Baker Road was knocked loose (but not detached), and a gutter on the front of a building on the east side of Baker Road (about 100 ft east of the power lines) was twisted and partially torn from the building. No other damage was evident to me in this area.
In Richmond, the damage path was a little larger. Trees and fences were blown down and branches were snapped along an erratic WNW-ESE path about 1/4 to 1/2 mi long and 100 yards wide in an area bounded by 19th Street to the west, Portrero Avenue to the north, 23rd Street to the east, and Hoffman Boulevard to the south. Much of the tree damage had not been cleaned up when I drove through the area at 2pm. Damage to houses looked minimal, although one house south of the intersection of 19th and Portrero was smashed by a large tree. Traffic signals on 23rd Street near the I-580 onramp were out of service.
As of Sunday evening, the NWS in Monterey had classified the Richmond event as a tornado. Since there was so little direct wind damage to houses - it appears this tornado was of F0 intensity (weakest rating on the Fujita scale, which runs from F0 to F5). The Castro Valley event had not been classified yet, but if it was a tornado - it would be ranked F0 as well if the damage I saw was the only damage this event caused.
The squall line associated with the damage weakened rapidly as it crossed the Diablo Range into the San Joaquin Valley - the third time a squall line had weakened like that in two weeks. Here in Turlock, we had moderate rain and 25 mph winds as the front passed. But the squall line seemed to have regenrated once it got to southern California - what's this I hear about damage in Long Beach AGAIN?! Isn't this the fourth or fifth time this year Long Beach has had either tornado or straight line wind damage? People in Richmond also must be wondering what they've done to deserve such frequent assaults from nature - a 4.1 earthquake had knocked items of shelves and shattered dozens of windows in Richmond just a day and a half earlier!!! Is this what they have to look forward to with La Nina???
Monday morning looks to be fairly chilly here. It was already down to 38F here at 8:45pm - skies were clear, winds were light, and the air was quite dry and free of haze. Stay warm.....