Warmer oceans means more water vapor. More water vapor means more rain in summer and more snow in winter. Recent snowstorms on the North Eastern coast is an example of the kind of weather that will become more common on the coasts.
Scientific News Explanation:
Let me put this another way, the movie, "The Day After Tomorrow" takes this very same concept of ocean warming and it's effects... and exaggerates it for the big screen:
Last Week Tonight with John Oliver: Climate Change Debate (HBO)
News: Survey finds 97% of climate science papers agree warming is man-made