A weather condition in which the amount of fallen snow, while not really such a big deal, wreaks havoc on a city, effectively shutting it down and leaving its citizens stunned and unable to see any sign of hope or a return to normalcy. It's perceived much like the aftermath of a nuclear event, but really... it's just freakin' snow!!
In cases of a Snowpocalypse it is really the panicked reaction of said citizens and NOT the actual snow that makes the situation worthy of the title. People simply aren't used to it, lose their heads and blame the city for the weather.
Seattle: December 2008/January 2009
6 days of sheer horror, the likes of which gripped us all in fear and ineptitude. God have mercy on our children as they look back on those dark, dark days of the Great Snowpocalypse.
** Speculation is still pending on whether this was the act of terrorists. No group has yet come forward and claimed responsibility.