Warped Front Rotors?

but he's still got pad left Ken,
so I'm thinkin' it's just accumulated brake dust, road dirt, grime.
hard to tell from the pics, but intermittent grabbin' and no signs of overheating.
I'm bettin it's grime.
The red tape idea's a good one tho,
think I'll start doin that.
 

I had a front tire put on about 5K miles ago, if they distorted the rotors would I have noticed it immediately? or would they distort over time?