Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 228 PM EDT Mon Mar 21 2016 Valid 00Z Tue Mar 22 2016 - 00Z Thu Mar 24 2016 ...Rain and mountain snow to continue for the northwestern U.S. into Tuesday... ...Heavy snow possible from the Rockies to the central plains and Midwest Tuesday and Wednesday... ...Warming trend on the way for the eastern U.S... The western U.S. will remain unsettled into Tuesday as a Pacific frontal system moves onshore, with rain and mountain snow persisting across the Pacific Northwest, central and northern California, and much of the Intermountain region into Tuesday. As this system moves quickly inland, it will overtake a lingering frontal boundary across the central Rockies. Widespread snow is forecast to develop across much of the central and northern Rockies on Tuesday, and continuing into Wednesday morning before gradually tapering off. By Tuesday night into Wednesday, the system will begin to move from the Rockies into the plains, as a surface low develops and deepens over the central plains. A polar frontal boundary will be settling southward through Tuesday across the central/northern plains and the Great Lakes, putting cold air into place and setting the stage for a potential round of significant winter weather from the central plains to the Upper Midwest and Great Lakes beginning on Wednesday. Beginning early Wednesday morning, heavy snow will be possible from the Front Range in Colorado/Wyoming east into the central high plains. Heavy snow will shift east into the Upper Midwest by Wednesday evening. Farther south, in the warm sector of the system, showers and thunderstorms are forecast to develop on Wednesday from the southern plains to the lower and middle Mississippi valley. Additionally, preceding this major system, an earlier round of rain and snow will move across the northern Great Lakes on Tuesday, and will reach the northeastern U.S. on Wednesday. Cold temperatures will persist for one more morning across the eastern U.S., with frost and freeze advisories and warnings in effect for much of the southeastern U.S. for Tuesday morning. Otherwise, temperatures will gradually moderate across the eastern U.S. through mid-week. With high temperatures by Wednesday reaching 5 to 15 degrees above average from the southern plains to the Mid-Atlantic and southern New England. Colder temperatures will remain, however, from the Great Lakes to northern New England, which will remain north of the frontal boundary that is forecast to become stationary. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php