My Dad worked for PG&E (retired ~14 years ago) and actually sent up weather balloons near one of their man made lakes at times for the people they had working in the office in San Fransisco. They had their own weather department. They used it for storm predicting (plant damage potential) and for cloud seeding around the lakes.
I'm assuming they still do it, since having those full of water means they have water for the summer months for the hydro they run. Feather River Canyon and Pit River area by Redding were two big areas they did a lot of hydro in (and still do, last I know, I haven't been back to CA since moving to TX 3 years ago).
I'm not too surprised to see them deploying sensors like this in various areas.
I remember my Dad telling my Mom about testing they were doing in the rural areas with the ability to turn off areas in case of load shedding need (he worked technically in "generation" not "transmission," mainly he was concerned with getting the water to the generators and maintaining the intakes and stuff at the dams, as well as the penstocks-the huge pipes that fed the hydro plants) Two years later I was out of school, working my first real job in Sacramento when they had the first rolling blackout due to the California ISO declaring a shortage in capacity. It would happen two times more during that summer, lasting 55 minutes each. But they tested that equipment on us in rural N. California a few years before.
