Severe storms to rumble and roar from Mississippi Valley to Atlantic coast
Dec. 9 (UPI) -- Thunderstorms will erupt this weekend as a strengthening storm system triggers severe weather that could threaten lives and property as early as Saturday afternoon over the Mississippi Valley, with the peak threat early Saturday night.
However, AccuWeather meteorologists also warn that damaging storms are also likely along much of the Atlantic Seaboard on Sunday and Sunday night.
The next round of thunderstorms will erupt Saturday afternoon and night and occur over a broad area that encompasses the middle and lower Mississippi Valley and much of the Ohio Valley.
Even though the air will be unusually warm and humid for December, it will take some time for clouds to erode and temperatures to rise high enough to help fuel the fledgling thunderstorms. During the period from the end of the day Saturday to the first part of Saturday night, there will be a moderate risk of storms turning severe with powerful wind gusts, hail and perhaps a few tornadoes.
The tornadoes are most likely to form from thunderstorms that are separated from a larger cluster of showers and thunderstorms.
The darkness and terrain in the region will add to the danger because people may not be able to see a twister approaching their location. The terrain in this region is not as flat as it is over the Great Plains but hilly with many wooded locations. It is possible that some tornadoes that form may also be shrouded by low clouds and could occur during heavy rain.
Later Saturday night, as the storms push into the zone from Ohio to central Kentucky, Tennessee and Alabama, southeastern Louisiana and the panhandles of Mississippi, Alabama and Florida, they will mostly pack a gusty wind and flash flood threat. At this point, the storms will take on more of a solid line.
That line of heavy rain will align with a cold front and advance eastward across the central and southern Appalachians and northeastern Gulf coast on Sunday morning and midday before reaching the Eastern Seaboard Sunday afternoon and night. High winds will accompany and precede the rain. Not all locations may experience thunder and lightning as the storms grind eastward toward the sea.
Heavy rain, high winds and poor visibility will make for major travel disruptions in the major hubs of Atlanta, Pittsburgh, Charlotte, Washington, D.C., Philadelphia, New York City and Boston. Ground stops and flight delays are likely.
Typically, severe weather peaks in the central United States and diminishes somewhat upon crossing the Appalachians and reaching the Atlantic coast. However, in this case, while the tornado threat may be brief and limited to parts of the Mississippi and Tennessee valleys early Saturday night, the parent storm and cold front will gain strength from Saturday night to Monday as they move along. This is why there is a significant threat of high winds along the Eastern Seaboard, especially from Sunday night to Monday.
Forecasters have outlined a moderate risk for severe thunderstorms across eastern North Carolina and a narrow zone in far southeastern Virginia. Wind gusts in some communities outside of thunderstorms and tornadoes may approach hurricane force. The AccuWeather Local StormMax wind gust is 85 mph for this event.
