An area of low pressure at the surface will organize tonight over the Gulf Coast states out ahead of the upper level trough, rapidly deepening during the day on Saturday as the low quickly tracks northeastward toward the coast of New England.
Anomalously cold air will filter in behind a series of cold fronts that will consolidate into a single system late Saturday over the eastern U.S.
Snow will begin to overspread locations from the Tennessee and Ohio Valleys tonight, with 1 to 3 inches of accumulation expected as far south as northern Mississippi into northern Alabama.
Higher totals are forecast just north into central Tennessee and the Upper Ohio Valley before heavy snow transitions to snow showers for late Saturday afternoon.
Farther east, rain will change to snow for the Mid-Atlantic states into southern New England early Saturday as winds turn to northwesterly and increase in speed.
Snowfall rates of 1 to 2 inches per hour are expected to combine with winds gusting up to 50 mph which will make for extremely dangerous travel given significant reductions to visibility on Saturday.
The highest snowfall accumulations are expected over central and northern New York into northern New England where 6 to over 12 inches are likely.
The storm system will continue to rapidly deepen as it exits into the Canadian Maritimes Saturday night leaving a dome of cold high pressure in its wake over the East Coast for Sunday.
Heavy rain, which is ongoing Friday evening across northern Florida, will continue though tonight, before coming to an end as the cold front pushes through the area Saturday morning.
Much colder air will be found in the wake of the cold front, as much as 20 to 30 degrees below average for this time of year, from the central to the eastern U.S.
Sub-freezing temperatures are forecast as far south as the central Gulf Coast to northern Florida with several record low temperatures expected Sunday morning, stretching from Louisiana to Florida, the Tennessee Valley into the Mid-Atlantic region.
Across the western half of the nation, fairly quiet weather will begin to become more active with the approach of a Pacific cyclone into Washington and Oregon late Saturday.
Periods of heavy rain along with heavy mountain snow will accompany this storm system which will spread east into the interior Northwest by Sunday morning.
After a brief break, another round of precipitation will begin to approach the Pacific Northwest Sunday night as another cold front nears the coast. ■