Several colder systems of varying strength will impact CA over the next week or so. The strongest in the series will begin to move in tomorrow afternoon, bringing significant to locally heavy rainfall in NorCal and very heavy snowfall in the Sierras (2-3.5 feet of it in some places). Strong-ish gusty winds to near 50 mph or so will occur along the coast and in the mountains, and an isolated thunderstorm is possible given the strong lift and moderately cold air aloft, either with the front itself or in scattered convective cells behind it. SoCal will see less from this system than NorCal, but it does currently appear that widespread measurable rainfall will occur and possibly local moderate to significant totals. No real flooding problems are anticipated (with the possible exception of the most vulnerable parts of the recent wildfire burn scars). Somewhat colder systems will roll into NorCal for the rest of the week, bringing moderate rainfall totals, lots of snow in the mountains, and possibly some convective activity (isolated thunderstorms and hail/sleet showers). Snow levels late on Thursday may drop into the 2000-2500 foot range in the north, but by that time only isolated to scattered showers will be left. Next week looks to be occasionally rainy, as well. SoCal will see generally light precipitation from all of these systems. No big storms on the horizon, unfortunately.