I have drawn a graphic illustrating the next few weeks of the weather pattern across North America.  The northern hemisphere will favor a regime towards an evolving combination pattern of a -NAO/-AO/+PNA.  The red in the picture represents the presence of ridging in the mid-upper levels and the blue represents the troughing areas of low pressure in the mid to upper levels.  The ridging over western CONUS and eastern PAC ocean along with ridging across AK, to northwestern Canada northeastward to Greenland supports a -NAO blocking pattern regime to expand and stay put through the end of the month.  How long this lasts no one knows for sure, but its presence while does not guarantee snow, it will bring a stormy and much colder air pattern across the eastern CONUS.