The closest bus you can take from Chatham to NYC is NJ Transit Bus #114. I had to be at work in NYC at 8AM this morning. I took the bus #114 from Mountainside, Route 22 at New Providence Road. It was 20 minutes drive from River Road to Mountainside Bus Stop but there plenty of busses you can catch.
Here's the Schedule for the NJ Transit Bus #114.
Here's the Advisory as of Monday, November 5th @12:50PM.