Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 315 AM EST Fri Jan 18 2019 Valid 12Z Fri Jan 18 2019 - 12Z Sun Jan 20 2019 ...Major winter storm expected to move rapidly across the Midwest into New England during the weekend... ...More heavy rain expected to impact the Pacific Northwest into northern California during the weekend... A low pressure system that has been tracking across the Pacific and then the western U.S. for the past few days is about to exit the Rockies into the central Plains. The low pressure system will be re-energized over the Plains as it merges with a strong surge of arctic air from Canada. Snow combined with very strong winds will spread across the Midwest and parts of the central Plains on Saturday. As the storm intensifies further on Saturday night, heavy snow is forecast to develop and rapidly overspread the Ohio Valley, reaching much of New England early on Sunday. The storm is expected to become quite intense on Sunday as its center passes near or just south of New York City. Conditions over interior New England could approach blizzard criteria as the storm brings very strong northerly winds together with heavy snow. Near and to the south of the storm track, much milder air from the south will keep the precipitation as rain. Over the Deep South, strong to possibly severe thunderstorms are forecast for Saturday from the lower Mississippi Valley eastward as a strong cold front approaches. In the wake of the storm, an arctic surface high will plunge southward from Canada and result in frigid temperatures across the Plains and the Upper Midwest, with temperature departures on the order of 15 to 25 degrees below normal! Meanwhile, mountain snows across the central and southern Rockies associated with the exiting low pressure system are expected to gradually taper off today. However, more energetic low pressure systems and associated fronts are forecast to reach the Pacific Northwest, bringing heavy precipitation and gusty winds across the region on Saturday. The precipitation is expected to shift further to the south across Oregon and northern California Saturday night into early on Sunday. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php