Huge storm issued for Perth tomorrow?

There is a huge storm hitting Perth, where i live tomorrow. (dont know your idea of storms but this is quite big because nothing ever happens in perth) :) they said its "severe" and winds could reach 125 kmph ... should i be worried? because i have school tomorrow. Is this a big storm? because there is lightning and about 50 mls of rain expected tomorrow. (a lot for our part of australia) Please just tell me what i should expect. I dont really like storms, they scare me :S thankyou