Courtesy of NOAA

A powerful upper trough currently swinging through the lower Tennessee valley has a history of producing heavy snowfall, significant icing, and numerous tornadoes. With that said, much of the same will possible as the system advances from the Tennessee valley to the mid-Atlantic on Wednesday. Moist and unstable air within the warm sector of the weather system will fuel widespread showers and thunderstorms across the southeastern conus. Low-level wind profiles across the coastal Carolinas depict significant turning of the flow with height indicative of the tornado threat. Consequently, the storm prediction center acknowledges this threat with a moderate risk of severe weather along the coastal Carolinas which includes the outer banks. Of course damaging winds are also expected as a squall line will likely develop.

Looking to the wintry portion of the storm, moderate to heavy snowfall will continue to the north and west of the surface low center. Given the forecast track of the cyclone, a swath of over 6 inches of snow will be possible from the upper Ohio valley Northeastward into the interior northeast. The HPC winter weather desk is currently advertising 12 to 18 inches of snow from extreme Western New York all the way up into central Maine. Given a residual low-level warm layer lingering above the cold surface, a mixture of freezing rain/sleet will be possible along the rain/snow line. It appears a quarter to half inch of ice accumulations may fall over sections of the central Appalachians as well as northeastern Pennsylvania/southeastern New York.