Well its a very complex thing- a lot has to do with the position of the jet stream that zig-zags around the hemisphere. This recent cold outbreak here was caused by a unusually strong high-pressure system over Ohio that sent the jet-stream funneling a constant supply of cold arctic air deep into the south. Usually pressure systems are constantly moving but this one just sat there keeping the cold air coming day after day.
I've read that as the arctic ice melts the soil and water absorb more of the sun's heat than reflective snow, so it's regenerative- melting ice causes even more ice to melt. But while we have all seen photos of ice melting in the arctic, I've read that the ice cap in the antarctic is actually growing.
So I don't think you can say the planet as a whole is doing any one thing- some parts are getting warming and some cooler. Some wetter- some dryer. The one thing I've concluded is nobody really knows. There's a Professor Gray who every year predicts how many hurricanes there will be. I don't know why because every year he's wrong. He said 2009 was going to be a bad hurricane year- it turned out to be one of the quietest ever. Meteorologists can barely tell you what's going to happen tomorrow- much less months and years from now.