Looks like a convergence zone is set up right along the immediate north shore. There was a similar set up yesterday along I78 in NJ and eastern PA. We alternated between clouds and sun and downpours. What was strange was how when the sun was out there were scattered CU moving from SW to NE like on any typical summer day however the surface wind was light from the east. This was the result. Like in your area there were crazy gradients in rainfall totals.