The weird frozen rain stuff? Not snow, not sleet, not hail. 雨氷 uhyou. Literally frozen rain. And it's really rare. Made the news. First time in living memory we've had it here. Apple farmers are grumbling they can't prune their trees as the branches are encased in ice. I'm not much of a farmer as I think that sounds like the perfect excuse not to be out there in subzero temperatures!
The 竹には雪折れ無し bamboo doesn't break under snow thing? Not just an agricultural maxim. The bamboo looks so spindly and weak and yet, even after being bent double with the wait of the snow it bounces back. Hidden strength. Unexpected result. If I really think about it maybe that's what the mud wall vs canonball saying is all about, too. Just can't say I've ever heard of it let alone used it!
A real なるほど I see... kind of day. And for you I summarised it all down into two paragraphs. For me it was two hours of roundabout conversation with my senior class to get those gems. Love that class. Don't really even need to prepare a lesson when you have 12 women who love to talk!