While we certainly don’t want serious flooding we do want a soaking rain and radars tonight are showing rain over Pennsylvania moving slowly into western New Jersey as of 8pm Thursday evening.
The key for areas east of western New Jersey and the Catskills is speed of movement and how much upper support will this have as it moves east. Models slowly weaken the upper support late tonight and during the day Friday. If the weakening can take its time these downpours could hold together better. They will be moving slowly so that helps at least prolong heavy rains. However prolong it over one spot for too long and you will wind up with local flooding so this needs to be watched.
The National Weather Service rainfall graphic shows the skewing of heavier precip from New York City westward with 1/2 the amounts forecast further east. The way it rains heavier to the east would be stronger cells and slower movement and we will watch radar trends for this overnight and Friday morning. 
The Weather Prediction Center is a little more bullish with precip in eastern areas and holding on to 2 inch plus rainfalls west. In a period where models tend to overdo precip we approach this with caution. Rain will spread east overnight and into New York City and points east Friday morning and then ending from west to east during Friday morning west of New York City and sometime Friday afternoon to the east.
