Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 249 AM EST Fri Mar 10 2017 Valid 12Z Fri Mar 10 2017 - 12Z Sun Mar 12 2017 ...Turning colder across much of the nation with a couple storm systems having snow potential... A major weather pattern change is in the works across the nation as an upper level ridge builds over the western U.S. and a deep trough becomes entrenched across the East. Sprawling high pressure over Canada will continue oozing southward across much of the central and eastern U.S. through the weekend, bringing much colder temperatures that are more typical of January to locations east of the Rockies. Expect temperatures to drop on the order of 15 to 30 degrees compared to readings observed on Wednesday and Thursday with the passage of an arctic front. Surface cyclogenesis is forecast to develop along this front on Friday near the New England coast and become a powerful nor'easter as it lifts northward across the Canadian Maritimes by Saturday. Accumulating snow is expected from Pennsylvania to southern New England with this system, with some locations receiving close to six inches of snow east of New York City. Another disturbance crossing the Plains and towards the Gulf of Mexico over the weekend will bring rain and thunderstorms back to the southern Plains and Deep South, and snow from the Midwest to Tennessee. Elsewhere across the continental U.S., expect dry and pleasant conditions for the southwestern U.S. where upper level ridging will persist. Very cold conditions will continue across the northern Plains and Upper Midwest with a few snow showers possible, and some lake effect snow is also likely downwind of the Great Lakes given the strong cold air advection. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php