The current forecast has some question marks, but Tuesday looks to be the best bet for snow right now. Fortunately for you, Northstar is quite sheltered from the ridge-top winds that can be really nasty on some other mountains. Also, it does not get the brunt of the type of storm forecast for this week comming from the west southwest. NOAA forecaster says:
TUESDAY STORM COULD BRING SIGNIFICANT PCPN TO WRN SLOPES OF SIERRA WITH
STRONG WSW FLOW AND OROGRAPHIC ENHANCEMENT.NorthStar is a bit unusual in that it lies East of the western Sierra ridge or what we call the Western Slope, and it is all below tree-line facing northeast. Northstar's weather will be moderated for this event by its location, orientation, and generally lower altitude. The storm direction being forecast will affect Northstar, but not a vigerously as it will places like Sugar Bowl, Squaw, Alpine Meadows, Sierra and Kirkwood. More eastern ski areas like Northstar, Incline, Rose, Heavenly will probably get less snow with this event, but summit winds can be high , especially at Heavenly, which is above tree line.
Have fun on your vacation. Don't worry about the weather. Taking a day off between ski days may feel right to you. You will know by Monday night. BTW, we just got back from Napa Valley, and its still very nice over that way if you are sightseeing.