Thousand-Year Storm is your main win con in this deck. Simply by multiplying spells, you burn enemy's face.

Opt good draw option, plus it will help you to gain additional storm counters for low price.

Anticipate . As long as u will need particular cards for particular situations, I think this card makes the best job at finding cards you need.

Electrodominance fits good to place your Storm, Ral or Niv-Mizzet at the opponent's end turn, otherwise it's a good burn spell which will also allow you to kick it ability spell with additional storm counter. Plus it will allow you to play mass removal in opponent's turn, which will can be found helpfull in particular match-ups (Selesnya tokens for example).

Absorb good counter which also allows you to live a bit longer

Pirate's Pillage for draw and mana in the form of treasures.

Cleansing Nova and Deafening Clarion mass-removal to help you deal with creatures.

Ral, Izzet Viceroy is your alternative win-con.

Mission Briefing is very good in your deck, as reanimation for your spell it also gets additional counter on your storm.

Brass's Bounty should give you lots of mana if you play it with storm counter more than 1.

Treasure Map will sift you topdeck and also will boost you up with mana after it flips

Lightning Strike removal for weak creatures and the main way of how you gonna kill your opponent.

In sideboard there are:

Banefire in control match-ups it is a good spell to finish the game or kill threat.

Negate to help you to deal with counter magic and agro's burn

Revitalize for agro match-ups.

Niv-Mizzet, Parun is good in control match-ups

More Deafening Clarion for agro and tokens match-ups.

Clear the Mind for long-lasting match-ups against control

Settle the Wreckage in Phoenixes/Drakes match-ups, or against Adanto's Vanguard.