Let is snow!

--snow generator
local snowflake, maxx, maxy, bShifted = "%", term.getSize()
local snowWin = window.create( term.current(), 1, 1, maxx + 1, maxy )
snowWin.setBackgroundColor( colors.lightBlue )
snowWin.clear()
while true do
    snowWin.setVisible( false )
    snowWin.setCursorPos( math.random( 1, maxx ), 1 )
    snowWin.write( snowflake )
    snowWin.scroll( -1 )
    snowWin.reposition( bShifted and 1 or 0, 1 )
    bShifted = not bShifted
    snowWin.setVisible( true )
    sleep( 0.1 )
end