It was originally called a "Bonus" instead of one of the official "Impossible Things", but with the news of Detroit breaking its largest snowfall record set 133 years ago by 1.2 inches; we can't help but upgrade it to the Fourth Impossible Thing.
Back in November and December "Steve, The Amazing" changed the weather in Michigan four times by request, at one point causing it to snow for an entire week in Frankenmuth when the weather called for no precipitation just days before.
Steve had also been warning people since January that it was going to snow in mid April, much to the chagrin of anyone that heard this prediction, as they had plenty of snow already.
Ironically, it's a very HOT debate whether the record would have been broken without one of those four weather changes at the start of the season. Some think that's why the weather change wasn't called an Impossible Thing in the first place...