Civilian planes don't normally land with snow or ice on the runway, because directional control becomes very risky at low speeds. At landing speed you initially

Civilian planes don't normally land with snow or ice on the runway, because directional control becomes very risky at low speeds. At landing speed you initially have control via the rudder, but once you're down tot taxi speed you can only steer the small rubber nose wheel which doesn't do much if it has no grip. Airports are continuously cleared / de-iced in adverse weather conditions. And if things become too bad, flights are cancelled.