Models showing the potential for a major Noreaster discuss..
1) heavy rain and potential for urban and street flooding given ample moisture and lift (low level jet of 60-70 kts at 925 mb!). Ensemble means are painting a widespread 3-5 inches of rain through Wednesday evening while some deterministic runs show as much as 8-10 inches. Though widespread amounts of this magnitude are unlikely, it is a concerning signal/trend, and urban/small stream flooding is a concern. The ECMWF probability of 4 inches of rain is 70-80%! (and 30-60% chance of that much within 24 hours). One additional concern this time of year is fallen leaves clogging storm drains, exacerbating street flooding.