Pretty sure this isn't working since Thunderstorm triggers a GCD.

http://www.worldofwarcraft.com/info/...guide-one.html

The /stopcasting command only works in conjunction with instant spells and abilities that do not trigger the global cooldown. These include trinkets and other items that have an "on use" ability. Experiment with your own arsenal of instant spells and abilities to see which ones do not trigger the global cooldown.
And don't talk about that software here. If you want to get help here, you must respect our rules and guidelines.