Cold and wet NorCal this week; some rain south?

After a cool/cold and dry week in the north (with the exception of the surprise snow flurries), the weather pattern will become substantially more active next week. A series of cold storm systems originating in the Gulf of Alaska will ride an increasingly zonal jet into NorCal by late weekend, bringing rain, mountain snow, and cold temperatures aloft. Snow levels will begin to fall with this first storm into the 3500-4000 foot range, dropping into the 2500-3500 foot range with subsequent storms later in the week. The second storm has the potential to be much stronger than the first–the current GFS has a pretty potent but small area of low pressure moving into the Bay Area from the NW on Tuesday, bringing locally heavy rainfall, strong winds, and possibly some convective activity. It’ll be interesting to see how strong this second storm system actually turns out to be, given the modle tendency to flip-flop on position/instensity over the past couple of weeks. More but likely weaker systems may be in teh offing after that…all with relatively low snow levels (4000 feet or lower). The entended GFS keeps at least a moderately active zonal jet over CA for the 16 day period, with occasional showery and cold weather, especially in NorCal. It is possible that we could see a couple of more substantial systems begin to be thrown into the mix, or potentially a significant cold convective event before the end of the calendar year. SoCal will be drier and not as cold, but at least some light precipitation and some snow at the ski resorts appears likely. Stay tuned…