With the National Weather Service issuing a severe weather warning for most of Wisconsin including Door and Kewaunee counties this weekend, local law enforcement is warning drivers that driving conditions into Sunday will warrant extra precautions.  Up to six inches of snowfall is projected with a second wave of snow in the area.  The winter storm is expected to start Saturday afternoon and continue overnight.  Heavy snow with gusty winds and blowing snow are expected to make travel difficult until at least Sunday morning.  The National Weather Service says there is still a high amount of uncertainty in the snowfall amounts as forecast models do not agree on exactly how the winter storm system will track.