Huh?
Are you seriously worried about snow? In Boston? For an airline based out of JFK? The Northeast Airports tend to all have plenty of snow removal equipment, de-icing, etc. Plus the storm 2 weeks ago was one of the 5 biggest in the last century. Don't get too many of those, and the upcoming storm in Boston may not even close the airport.
I think Jetblue found success much more quickly in Boston than they were expecting. Does that warrant the kind of expansion they have in mind? Maybe. But adding one gate every six months or so over the next 3 years should allow them to manage their growth more evenly.
I don't think snow is even on their radar.