@bunbuku
Is this sentence good enough that you would adopt it?
I assume that the intended meaning is this:
The school is closed due to snow.
I wouldn't use 閉鎖 for that meaning, but it seems to be used by some people.
https://www.google.com/search?q...&bih=625&dpr=1
Perhaps it could be more formal than 休校, but I'm not sure.
[#1396361] is a sentence with 学級閉鎖 which has a similar meaning.