I would add to seasons improvement that lake ice need to be decoupled form snow dept, at least in North-America where cold can be strong but precipitation may be low. Now lake ice is present at a minimum of 72 cm dept in the sim. So while there is ice on lakes right now in eastern US and Canada, there is no ice up North. Example here is Shefferville CYKL, N 54 deg., where it is -26C right now and no ice in the sim. It is like that down to Pennsylvania where there is no ice in the sim. See this post : Lake Ice Should Not Be Linked to Snow Depth in North-America - #3 by Guillaume3511
