Those familiar with Warcraft II or Warcraft III will recognize this classic mage ability. Blizzard is a mage ability learned at level 52 for those with the frost specialization. It deals its damage over 8 one-second long ticks, each doing 1/8th the total damage.
Like all channeled spells, the mana cost is deducted before channeling starts, so the full cost is paid regardless of how long the mage gets/needs to channel before the spell is interrupted or the target is dead. The spell is best used against crowds of targets that are not able to hit mages to interrupt channeling.
Modified by Edit
Frost specialization ability
Most mages find this spell hard to cast fully in PvP. Because of the large number of debilitating procs on the spell, as well as the high damage output, many targets will immediately begin seeking out and subsequently killing the mage casting Blizzard. However, in large or confusing battles, or from sufficient cover, it may be possible to cast the spell to its conclusion, doing great damage and snaring the targets for the duration.
A single tick of damage from this spell is enough to reveal stealthed opponents and apply the snare; this can be useful in limited circumstances.
Blizzard is a great tool to rapidly gain experience and to smash whole groups of mobs at once making it a powerful farming spell as well.
- When focusing on Blizzard, +spell power is very useful. Increasing your spell hit chance will make it less likely that mobs resist single waves of Blizzard and hence reducing the danger of mobs breaking free of the slowing effect. Remember the base miss chance versus spells of mobs which are the same level as your character is 5% and can be negated by sufficient spell hit gear.
- Ideal locations for this tactic have large numbers of mobs that have few or no ranged capability. These mobs will be caught in the snare and will stay packed together, walking very slowly towards you, as you continue to cast Blizzard spells.
- As Blizzard is very expensive, maximize your effectiveness by attracting as many mobs as possible at once.
- can help to gather mobs from a distance without exposing yourself (immediately, at least) to their melee attacks.
- and your mount can help while gathering mobs together. may help or hurt; it keeps mobs off you while gathering, but may keep them from being close enough to hit with your blizzard.
- If the cooldown is acceptable, can be used after gathering mobs, causing them to all catch up to you and surround your invulnerable body.
- Use (especially if you're using the Ice Block method, above) to freeze mobs you have gathered and gain some distance from them before beginning your blizzard casts. Alternatively, if you are able to get range through other means, save it to regain distance if your first casts do not kill your targets before they reach you.
- Mages can use their water elemental beginning at level 10 as an additional slow effect, usable at range to slow your targets' progress towards you.
- If the mobs reach you before dying, use Frost Nova to regain distance. Alternatively, if they are low in health, a cast of may finish them off.
This mage, wizard, and sorcerer spell calls freezing sleet, snow, and hailstones on foes. The cutting ice shards and hail pound down upon the caster’s enemies and foes, battering them and causing slashing, impact and cold damage.
Calling down shards of freezing ice to batter and rend their enemies, Archmagi have been known to rout entire armies using this spell.  One of the Alliance’s most feared spells, Blizzard has become even more effective and deadly since its original inception during the First War. Summoning torrential storms from the frozen Mountains of Northeron, this potent spell calls down a fierce tempest of ice to assault the enemies of the Mage with a flurry of cold blades. Blizzard can be cast over large portions of the battlefield, making it an extremely powerful spell when facing legions of Orcish troops. 
Patch changes Edit
- Patch 6.0.2 (14-October-2014): Blizzard is now available only to Frost Mages.
- Patch 5.3.0 (21-May-2013): Blizzard now deals 40% more damage.
- Patch 4.1.0 (26-Apr-2011): Blizzard damage has been increased by 70%.
- Patch 3.3.0 (08-Dec-2009): The tooltip on this ability will now update properly from all talents which increase its damage by a percentage. Also fixed a bug where some trinkets were not triggered by this spell.
- Patch 3.0.8 (2009-01-20): Can now trigger the talent Brain Freeze.
- Patch 2.4.0 (25-Mar-2008): The casting bar will now display properly when casting Blizzard with spell haste.
- Patch 2.2.0 (25-Sep-2007): This spell is now affected by area damage caps. Its bonus damage coefficients have also been increased.