At the time of the Global Precipitation Measurement (GPM) Core Observatory overpass (April 1, 2017, 0550 UTC), the storm's center of low pressure was south of Long Island. At the mid-levels of the atmosphere, the circulation was centered over northeast Pennsylvania. This led to a classic overrunning, warm conveyor setup, which happened when the counterclockwise low level flow drew in cold air out of the north/northeast (hence "Nor'easter") from Canada.
At 5:05 p.m. EST Monday, Jan. 26, 2015, the Global Precipitation Measurement mission's Core Observatory flew over the Nor'easter that dumped snow on New England. This satellite image shows the rate of rainfall, with low amounts in green and high in red, and snowfall, in blue to purple. The center of the storm, shown in 3-D, was offshore with far reaching bands of snowfall. More intense snow rates are shown in darker blue, which can be seen on the northern edge of the storm.