So how does this happen? Bascially the hurricane comes up the coast and merges with a potent Arctic cold front over near the Great Lakes and then BAM - several inches of show with perhaps tropical storm winds. There could also be flooding along the coast of NYC and New England. In short, if this happens we will have a huge mess on our hands. 

So is it just the normal "weather panic" or actually something to be worried about? The Wall Street Journal has a quotation from the Hydrometeorological Prediction Center, which is the usually calm department of the National Weather Service:

A POWERHOUSE CAPABLE OF WHIPPING THE ATLANTIC INTO A FRENZY AND CHURNING UP DANGEROUS TIDES”,

They said that in regards to this storm. Yikes! They also added:

a full moon early next week could boost coastal flooding amounts by an additional foot or so

Before you get too worried though this could also just blow out to sea and Halloween will carry on as usual - but even the most cautious of weather professionals are raising an eyebrow with this one. If it does it'll certainly be a historic storm.

[WSJ]