I'm not an expert, so feel free to take this with a grain of salt, but I'm not really seeing how this team benefits from hail. I'm also confused about your Mienshao...if you send it out while hail is up, that negates its Focus Sash.
Let me know what items, moves, Pokemon or EV's should be changed.
Firstly Icy Rocks makes Hail 8 turns, and all of your pokemon except abomasnow is affected by the hail damage, how is this a hail team? With regards to the base speed abomasnow has, it won't stay alive long in this battle. Yes as the previous guy posted, hail will cause your focus sash on mienshao to stop functioning, as it only works when the pokemon has full health. 3/6 of your team are non sweepers, forretress, vaporean and clefable. I think it's high time you should add in some sweepers and remove that abomasnow to reduce the damage done to your team. Trust me, Sheer cold is something you should not have learnt. 30% accuracy = giving a free turn for your opponent to set up and laugh at you, given that poor speed you have.
Pokemon X FC 0404-6641-5075 IGN Soon Liang Pokemon white FC 4727 8123 1292