You don't fight Meowiarty until you get to the top of Big Ben. That battle has you fight against Meowiarty, a rank 6 boss with 2500 HP, Agony Wraith, a rank 5 boss with 1600 HP, and a non-boss rank 5 mob with about 520 HP or so. Yes, that's 1 on 3. But that's okay, storm matches up fairly well, since Meowiarty is myth.
. I am a level 27 storm/ice wizard.