Yes it was.
It was so real, but I think I was too much in shock to find it terrifying, otherwise I would have put this in the "Nightmares" thread. It made me wonder if that's how I'll feel if Rainier really blew.
One thing I do know though, with how much I absolutely adore that mountain, if she ever blew, once the shock wore off I'd cry as if a close friend had just died. I'd be very much shaken up over it.