Really, we are in a fairly bad area for massive storms. In most cases we are too far inland for the large coastal "nor'easters" with several notable exceptions such as the march 1993 blizzards.
For storms that approach from our southwest they tend to pull up warm air from Gulf of Mexico and tends to turn out precipitaton to ice or rain. I'm sure you can remember a bunch of times here that we got 3 or 4 inches of snow, only to turn over to ice and then rain.
Also, there is a phenomenon where low pressure systems track up roughly along the Ohio river, and when they get to around our area, they transfer the energy they are carrying to a new low pressure system off the coast, and the precipitation with the initial system fizzles out here, and places like D.C., philly, NYC get huge storms.
Basically, there are two ways for us to get huge storms. One of those coastal storms track up over a path roughly on I-95 or a little west, and while it rains in New York we get snow. That was what the march 93 storm did.
Two, like the storms I mentioned earlier where they track up the Ohio river and transfer, we need the transfer to happen late enough that we still get snow from the initial system, but also have the new "coastal storm" be far enough west and large enough to keep throwing snow back our way and we also need it not to get too warm. Our big storm in February 2010 is an example of that.
That is a VERY rudimentary explanation, and I am not a meteorologist at all. In any case, I do hope that helps explain things at least a bit.
