um...OK.
I don't set out from home on my bike if there's lightning, but if I'm riding and it starts, I generally keep riding and just avoid open spaces like parking lots or bridges. My commute home is all old-urban and there are lots of tall buildings along the way which I assume (maybe stupidly) will act as my lightning shields. I'd be more worried about windbursts either blowing me off my bike or throwing a tree limb in my face, and I would be inclined to seek shelter if it was getting really gusty, not if it's just flashing.
RGC