Enduring Winter

Enduring Winter
Enduring Winter (3 ranks) Increases the duration of your Summon Water Elemental spell by X sec and your Frostbolt spell has a Y% chance to grant the Replenishment effect to up to 10 party or raid members mana regeneration equal to 0.25% of their maximum mana per second for 15 sec. This effect cannot occur more often than once every 6 sec.
Requirements
Class	Mage
Talent required	[Summon Water Elemental]
Properties
Affects	[Summon Water Elemental], [Frostbolt]

Enduring Winter (formerly Improved Water Elemental) is a talent in the Frost tree, you will need to spend 44 points in Frost to max it.

Mechanics

Using 3/3 Enduring Winter is problematic for raid-wide replenishment, since as the buff is refreshed with every cast of Frostbolt, it'll very often be reset before it can properly tick and an odd tick cooldown will be placed, screwing up raid mana.
For instance, if you have a 1.9 second-cast [Frostbolt] due to combined haste effects, there is a whopping 1.9 second distance between ticks, seriously hurting raid mana regeneration. In a raid environment, using 1/3 Enduring Winter is currently agreed upon as best choice for being Frost or offering Replenishment. You'll lose pet uptime, but that's still better than wrecking your raid's casters.

Rank table

Rank	Duration	Chance to regenerate
1	5 sec	33%
2	10 sec	66%
3	15 sec	100%

Patch changes

• Patch 3.1.0 (2009-04-14): Renamed Enduring Winter. Instead of the Water Elemental increasing mana regeneration for the Mage's party, casting Frostbolt now has a 33/66/100% chance to provide the [Replenishment] buff to up to 10 people in the Mage’s party or raid.
  
• Patch 3.0.2 (2008-10-14): Added.
  

External links

• Wowhead
• WoWDB