Used it and it's nothing more than a rain dance. I used it (yes, all 3 words) and stood there waiting for the dragon to get lit up. Waited...got spit on with fire...waited...more fire...waited...healing pot....waited...more fire...this continued for a while and his health never even got touched. I saw 2 lightning bolts but there were up in the sky and didn't even look like they almost might hit the dragon.

Is the shout bugged?

Should be seeing lightning hit it, so if not, yes.

It keeps killing my companions. Not good.....

Sounds like it may be bugged then. Well good to know.

Thank you for the replies

I don't recommend ever touching stormcall unless you're inside a dungeon and don't have a companion with you,i used it in falkreath when being attacked by a dragon,ended up fighting the entire town.

Also used it in the wilderness,after killing some flame atronachs i walked to a town,took me a good few minutes,and again all npcs got lightning bolted,damn thing takes a while to wear off.

its the same for my partner on the xbox and a few of his friends also on the xbox iv never had the shout so i cant say for my ps3 copy but yea it appears to not do what it says it does

Yeap storm call kills everything except you, try casting it in whiterun its funny as
The Storm Call shout creates a thunderstorm above the Dragonborn's head that throws powerful bolts of lightning down upon anyone underneath, friend or foe. Take care when using this shout, as if it is used in a town it will damage and most likely kill many citizens. The shout can also only be used outside.
The Elder Scrolls Wiki

I have used the shout inside dungeons,you get the sound effects,rain and stuff,although as far as i can tell it doesn't actually damage anyone,so you can use it it just doesn't work as intended.