Trying my hand at making a macro for my (enh) Maelstrom spenders.

Basically, If Tempest has procced i want to use that but any other time i want to cast Lightning Bolt only after my 2 stacks of Elemental Blast are on cooldown.

This is my current macro which is functional but i want it all in one castsequence so that the tooltip/icon will correctly show all the info

Code:
#showtooltip

/cast [known:454009]Tempest

/castsequence Elemental Blast, Elemental Blast, Lightning Bolt
After some research i know i can make something like this below, however this isn't working

Code:
#showtooltip

/castsequence [known:454009]Tempest; Elemental Blast, Elemental Blast, Lightning Bolt
Any thoughts where I'm going wrong here?