Like someone else said, you likely have a wiper pressure problem. If you look on the backside of the wiper arm itself you will see a spring. These springs tend to rust out pretty badly. The springs in my X5's wiper arms are destroyed - and she's spent her whole life in the southeast. Being that you are in the northeast, with your salty winter roads, etc., rusty springs may very likely be your problem. I'd take the wiper arm off and try to stretch and clean the spring out (some of the coils may be rusted together/apart, not allowing them to expand/contract - if rusted apart, forget it, you'll need a new arm). If that doesn't fix your problem you'll likely have to buy a new wiper arm. If you have to buy a new wiper arm, I'd probably go ahead and replace the other too. Whichever route you go, spray some lithium grease on the clean spring every once in a while and work it in with your hands. This will prevent it from rusting too quickly. I'd do this about once a month during the winter months and only once at the beginning of the spring when the snow clears (which should hold it over fine until the following winter).

Good luck!