So doing some more testing and I agree that Cat 5 needs so more "oomph" up front. The concept of a storm building and raging is nice. But in the reality of playing it doesnt work as well. Reverse the concept.. Storm hits like a truck and then dies down.. which is still in the realm of " reality "
I tried some more characters for comparison.
Ice/Cold Corrptor drops
Sleet-- Good size Debuff
Ice Storm
Blizzard
Not only does the mobs melt, but the area of effect, stacked slows and knockdown keeps the mob pretty much in the area until everything is dead or darn near dead. And Ice Storm and Sleet will come back up almost at the same time Blizzard power duration ends.
Ice/Storm Defender does the same thing with Freezing Rain, Ice Storm and Blizzard and can throw in a Tornado and Lighting Storm for good measure.
The Storm Blast/Storm Corruptor takes more time to defeat the same sized mobs. Many mobs scatter so they dont get the full effect of Cat 5, The slows arent enough to keep mobs from running away, Sometimes Storm Cell chases a foes leaving the area where I placed it..
Why doesnt Storm Blast have a power like Chained Fences that could be a cone with an AoE immobilize? That would help do damage AND help keep some foes locked down in an area.