Freakiest thing I've seen/heard in some time

So this morning at 5 AM I was startled awake by the loudest, scariest, ground-shakingest sound that I've ever heard. I quickly jumped out of bed as numerous car alarms in the neighborhood went off, put my glasses on and looked out my window to the snowy streets below.
I initially had 2 thoughts when the earthshakingly loud bang woke me - the first was that the new townhouses that are being built across the street from me somehow had some structural damage that caused them to collapse; the second thought was that a plane had crashed on the way to/from SeaTac.
But as I looked outside, besides from the heavy snow coming down and a few curtains being pulled back by neighbors to turn off car alarms and to check what the deal was, there wasn't anything amiss. I still had power so I knew it wasn't the transformer on the corner blowing out - what the hell had happened?!
I got my answer a couple of minutes later when, still looking out the window, I saw a bright flash of light hit the street shaking the ground, followed within seconds by the horrific booming clap of thunder. Thunder and lightning during a snow storm!!! The snow eerily made the lightning look like an alien space laser. I guess I've never been that close to lightning hitting the ground so I never knew how powerful and ground-shaking it could be. And as rare as thunder and lightning is out here in the Pacific NW, I've never heard of either happening during a snow storm or blizzard - that doesn't really make a lot of "Physics" sense to me, but oh well.

It scared my two pets enough for them to want to (temporarily) share the same sleeping space. I seriously think the dog thought the world was coming to an end.