Well my Grandfather had the six day rule for rain, but never heard him mention snow. You can keep it, but I think it is coming this way, cold next few days.
Take it from a Northerner - we all have to deal with Jack Frost every few years or so after crops are up. Your corn will be fine. As long as the growing point is still below ground, frost can smoke the tops right off and it will grow back. Beans are tougher than we give them credit for too so I believe you'll be ok there too. Don't know about Milo though....
