Yesterday's rains (1.26 inches near my house) will do little to refill California's reservoirs. The primary source of water for the reservoirs is precipitation in central and -- most important -- northern California. Some cities in southern California -- including Los Angeles
-- do attempt to capture rainfall and use it to replenish underground aquifers. And, of course, we all will be using less water for a while to irrigate our gardens.
Where I live, we do not get any water from the Colorado River. A slight increase in its flow from storms in the northern part of its watershed will mean a slightly less demand for water from the California Water Project's dams and aqueduct.
Thus, we are getting some minor relief. At this stage of the drought, even minor relief is welcome.
Today, I have not seen any rain. The weather is hot, cloudy, and extremely humid. The 9:00am PDT forecast is for 50%-60% probability of measurable rain this afternoon, this evening, and daytime Monday. "50%-60% probability" means that 50%-60% of the area will experience some rain, not that all areas have a 50%-60% probability of rain.
As of 30 June, 12 major California reservoirs were collectively at 37% of capacity. That is less than half the historical average for that date.