NEW YORK – A powerful two-pronged winter storm that will span nearly 2,000 miles is set to bring stark contrasts across the nation this week. While parts of the Northeast brace for icy conditions, the South faces the threat of torrential downpours and flash flooding.Travelers should anticipate significant disruptions, while residents should prepare for potential floods, severe thunderstorms, strong winds and heavy snowfall.Multiple rounds of heavy rain will drench the Deep South, particularly Texas, Louisiana, Alabama and Georgia, the FOX Forecast Center said. Rain totals will range from 2-3 inches, with locally higher amounts of more than 5 inches possible. DAYS OF HEAVY RAIN TO SOAK DEEP SOUTH AS FLOOD THREAT INCREASES FOR NEW ORLEANS, MOBILEThe worst rain is expected in places like Louisiana and southern Alabama. Late Tuesday will be the biggest period for flash flooding as the threat grows to cover cities from Atlanta to Mobile, Alabama, and eventually the entire East Coast.Additionally, a low threat of severe weather is possible on Tuesday and Wednesday. Damaging wind gusts and a tornado or two will be possible as the cold front rapidly moves through.The Northeast will experience a different kind of winter weather. Rounds of beneficial rain will soak the Northeast and the Interstate 95 corridor likely through the early hours of Thursday, the FOX Forecast Center said. Areas along I-95 could receive 3-5 inches of rain. On Monday, cities such as Pittsburgh, Columbus, Ohio, and Charleston, West Virginia, started their day under umbrellas.By Monday afternoon, the heaviest rain is expected to impact major urban centers along Interstate 95, just in time for the evening rush hour. While flash flooding is not anticipated, travel may become difficult during any downpours.MILLIONS IN NORTHEAST FACE FLOOD THREAT FROM RAPID SNOWMELT AS WARMER TEMPERATURES FUEL SOAKING RAINSThe second round of rain will come Wednesday with a much larger system, as a powerful cold front drenches the eastern third of the Lower 48.Wednesday is shaping up to be a washout, with an elevated risk of flash flooding along the I-95 corridor, the FOX Forecast Center said. This rain will arrive well ahead of the advancing cold front, driven by tropical-like moisture streaming out of the Southeast.The most significant impacts are expected from New York City to Boston. Some locations could see over 3 inches of rain from both storm systems combined.While this rain won’t entirely eliminate drought concerns, it provides a meaningful boost as we approach the new year, the FOX Forecast Center said.HOW TO WATCH FOX WEATHERAs colder air rushes back into the region behind the cold front fueling Wednesday’s rainfall, rain could mix with or change over to snow over parts of the interior Northeast and New England by Wednesday night.However, due to the wet ground and warmer temperatures before the winter weather arrives, it’s too soon to predict where snow will fall and how much could accumulate.The Great Lakes region, already battered by recent snowstorms, is facing another round of lake-effect snow expected to start Wednesday and continue into Friday.A strong snow band is expected to develop off lakes Erie and Ontario, but its exact position is still uncertain, the FOX Forecast Center said.DOWNLOAD THE FREE FOX WEATHER APPIf winds shift more to the southwest, the heaviest snow may target western New York. Otherwise, lakeshore areas from Lake County in northeastern Ohio northeastward to parts of northern Ashtabula County in Ohio and Erie County in Pennsylvania could see the biggest impacts.Snowfall patterns may shift temporarily with a secondary front on Wednesday night, but heavy snow is likely for lakeshore communities during this event. Download the FOX Weather app to get our livestream, 3D radar and weather alerts anywhere you go.