Shaman's Apocalypse skill doesn't work with Wildsurge Incantation keystone

Apocalypse has both storm and spell tags and should work with Wildsurge Incantation to give 50% more damage and having 75% less duration. However, with the keystone, the duration remains unchanged and only the Hailstorm damage has increased, with the damage of Meteor and Crash Lightning unchanged.

It only works on the Hail"storm" because that's the only "Storm" part of Apocalypse. Its a little confusing since its in the tag of the skill.