I, too, read the reviews about Dark Sky. For what it's worth, I have not been overall satisfied with it's predictions. For me, it's only been maybe 25% accurate and I am also in CA.I think the idea is good, but several times, I have received notifications about certain weather occurring within xx amount of minutes, for it not to occur at all.
Your milage may vary.....
yahoo weather has started giving those "100% chance of rain in the next 15 min" notifications.... i think one time we got a couple sprinkles.... the other times: nothing! and i don't recall getting a notice at all yesterday! haha!