Snow will be developing overnight from west to east and north to south.  At the same time cold Arctic air will be invading the Cowboy state.  Snow will be heaviest across the western, northern and central mountains and then in east-central and northeastern Wyoming.  Several inches of fluffy snow will be possible at lower elevations with a foot or more in the mountains by Friday night.  Far southeastern Wyoming will miss out on much of the snow.  This weekend will be very cold with a few snow showers in the western mountains.