A spring-like storm system is unfolding across the central U.S., with Texas, the Southern Plains, Mississippi and Ohio valleys seeing heavy rain, increased flash flood potential, a few severe thunderstorms, and even wintry weather this weekend. A low-pressure system is moving through Texas this morning and will advance into the Mid-Mississippi Valley as it rides along a stalled warm front stretching through the Mississippi Valley and into the Great Lakes. As the low-pressure system slides eastward, it will draw warm air northward while pushing cold air southward behind it. The clash of these two air masses will produce severe thunderstorms across the Lower Mississippi Valley, with the potential for strong tornadoes and wind gusts of 60 to 70 mph. The threat is significant enough that the government`s Storm Prediction Center has issued a Moderate Risk for severe thunderstorms capable of producing damaging winds. Cities in this enhanced risk for severe storms include Memphis and Nashville, Tenn., Jackson, Miss., and Alexandria, La. Surrounding this is a broad area of severe thunderstorm risk that stretches from Texas to the lower Ohio Valley. Houston, New Orleans, Huntsville, Ala., Louisville, Ky., and Cincinnati, Ohio, are among the cities that could be at risk for dangerous thunderstorms. The low-pressure system will allow warm and humid air to slide northward, being squeezed out as heavy rain this afternoon and evening. The heaviest rain will fall Saturday afternoon into Sunday afternoon, where 2 to 4 inches of rain will fall from the central Gulf Coast all of the way into the eastern Plains. The bull`s eye of rain will be the central Mississippi and much of the Ohio Valley, where rainfall totals will be 4 inches. This amount of rain, plus the recent snowmelt, could trigger flash flooding. Already, Flood Watches and Flash Flood Watches stretch from eastern Oklahoma northeastward into western New York. The rain will spread into the Northeast and New England early Sunday. The rain will be accompanied by unseasonably mild temperatures with 50s across southern New England and most of upstate New York and 60s and low 70s across the Mid-Atlantic. A combination of the warmth and rain will cause the recent deluge of snow to melt, increasing the amount of water running into river, streams and storm drains. Flooding in low-lying areas, poor-drainage urban locations, and along streams and rivers are likely through Sunday. WeatherBug will be watching this developing weather situation and its effects on travel for the weekend before Christmas. Check back often for our updates. Be sure to keep WeatherBug active to receive the latest weather in your neighborhood and get the latest updates anywhere on Twitter. What do you think of this story? Click here for comments or suggestions.