Interesting weather site...

[CT4ME]

Ventusky.com, similar to windytv.com

I like the Ventusky interface, but Windytv seems to have a few extra features for pilots

 

[NealRomeoGolf]

I use windytv a lot. I'll have to check this other one out.

 

[upstateny]

Also interesting -
http://en.blitzortung.org/live_lightning_maps.php
http://en.blitzortung.org/live_lightning_maps.php

Real-time lightning strikes