Yes CA has interesting requirements. If you have AWD with M+S tires you can drive without chains with level 2 restrictions, there is no 'snowflake' winter tire requirement. Though you always have to carry chains. Most proper winter states have more stringent requirements.I think for many AWD is usually considered a sufficient bar of driving in the snow. I've noticed e.g. in the Sierra Nevadas in California, the only question the transport authorities ever ask at checkpoints is whether I have AWD, never any questions about snow chains or winter tires - even though the regulations say AWD + snow tires or chains, no in-between.