Nor'easters form when warm moist air traveling north with the Gulf Stream up the coast collides with cold air travelling down from Canada. The combination of moisture and cold can develop into snowstorms. In Jan. 2015, these air masses collided into a storm that brought blizzard conditions with, as of Tuesday morning, up to 30 inches of snow and 70 mile per hour winds across parts of Connecticut, Maine, Massachusetts, New Hampshire New York and Rhode Island. Lesser snow totals also hit New Jersey, Pennsylvania, Maryland, Virginia and West Virginia. Snow is expected to continue to fall into Wednesday as the storm moves northeast up the coast.
The GPM Core Observatory carries two instruments that show the location and intensity of rain and snow, which defines a crucial part of the storm structure – and how it will behave. The GPM Microwave Imager sees through the tops of clouds to observe how much and where precipitation occurs, and the Dual-frequency Precipitation Radar observes precise details of precipitation in 3-dimensions.
GPM data is part of the toolbox of satellite data used by forecasters and scientists to understand how storms behave. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency. Current and future data sets are available with free registration to users from NASA Goddard's Precipitation Processing Center website.