Damn these things last long. Has to be too long. I just went by a snowstorm that was put up by an invoker I was fighting the day before - real time. We're talking 12 hours real time. That's like a year in thera isn't it? Got to be a bug that it lasts so long.

At least, I can concieve of circumstances in which one could last that long. There are modifiers on how long they stick around, and without going into too much detail, their duration isn't precisely measured in time.