A significant winter storm is expected to impact a large portion of eastern U.S. regions over the weekend, bringing a variety of weather threats to those areas that include heavy snowfall and severe thunderstorms.
The National Weather Service (NWS) said in a statement the storm system will produce weather threats over parts of the Ohio/Tennessee Valleys and the interior eastern U.S.—going as far south as Georgia—starting on Friday and continuing through Saturday night.
"Heavy rainfall and severe thunderstorms [are expected] to impact the Southeast and Mid-Atlantic this weekend," the service said in the latest update, noting that the greatest snow accumulation is expected across portions of the Northeast, where totals in excess of 12 inches are likely.
Beginning late on Saturday, cold air is expected to spread across the Southeast and Mid-Atlantic, with temperatures going below freezing along the Gulf Coast and northern Florida. The storm is expected to rapidly strengthen into a bomb cyclone by Saturday.
The snowfall could lead to "scattered power outages due to the heavy and wet nature of the snowfall," the NWS said. "Snow rates of greater than 1″/hr, combined with gusty winds will produce blowing and drifting of snow and severely reduced visibility," it added.
According to AccuWeather meteorologists, millions of Americans will face some type of impact from the massive storm system that is expected to strengthen into a bomb cyclone along the East Coast, bringing strong winds and frigid temperatures.
A so-called "bomb cyclone" weather phenomenon is a winter storm that is created through a process called "bombogenesis"—which means the storm will see a rapid drop in atmospheric pressure, plummeting by 0.71 of an inch of mercury or more within 24 hours.
Winter storm warnings have already been issued for residents in a number of states, including Alabama, Ohio, Tennessee, North Carolina, and Oklahoma.
Heavy snowfall will end across regions on Saturday night, but forecasters advised people to take caution while traveling as icy spots on untreated roads could linger into Sunday across the Northeast as temperatures plunge below freezing.
"Blizzard conditions, which occur when the visibility drops below 1/4 mile or less and winds frequently gust to 35 mph or greater for three consecutive hours, are most likely to unfold across northern New York and northern New England on Saturday," AccuWeather Senior Meteorologist Courtney Travis said.
Meanwhile, the Storm Prediction Center (SPC) announced that several tornadoes could form across regions in the Southeast and Carolinas.
"Damaging wind, isolated hail, and a few tornadoes are possible across the central and northeastern Gulf Coast to the Carolinas and northern Florida," the SPC said. "Isolated severe thunderstorms are possible during the day, but the greatest threat appears to be late [Friday] into Saturday morning."
The strongest wind gusts and thunderstorms are expected to hit portions of the coastal mid-Atlantic and New England, as well as in the southeastern U.S. corner, where AccuWeather meteorologists predict winds will reach speeds of 70 to 90 mph.
Winds of this magnitude are able to knock down trees or break off tree limbs and cause extensive power outages and property damage.