Wiktionary
n. (context idiomatic slang English) Little or no likelihood of occurrence or success.
Usage examples of "snowball's chance in hell".
But it didn't take much waking thought to arrive at the conclusion that there was only one way-only one possible way-that gave us a snowball's chance in hell of getting out of the lens.
You'd think that'd be one time when the devil didn't stand a snowball's chance in hell.
If it didn't fall right off onto the floor when you tipped the shelf up, it probably slid to a place where you haven't got a snowball's chance in hell of getting hold of it.
Frankly, I don't think it has a snowball's chance in hell of being accepted.
You haven't a snowball's chance in hell but still you won't give in.
Al-Ibrahimi hadn't gone through the roof when Farrell made the request, but Farrell no longer thought there was a snowball's chance in hell that the manager was going to pull C41 from the project.