SPC severe weather outlook for Saturday afternoon. (NOAA /NOAA)

With an extremely moist and unstable atmosphere in place, residents in the lower Mississippi Valley are bracing for several hours of severe weather Saturday afternoon and evening, featuring storms capable of producing long track and violent tornadoes.

Tornado watches are already in place across parts of the region and the potent storm system has already been producing strong tornadoes in eastern Texas.

As a strong upper level and surface low pressure system continues to rotate eastward through Texas on Saturday, clusters of thunderstorms developed Saturday morning across much of the state. In addition to tornadoes, many of these storms featured heavy rain, large hail and damaging winds.

The biggest concern for tornado development is on Saturday afternoon and evening, as the potent piece of energy slides eastward into Louisiana, clashing with a very strong inflow of moist and unstable tropical air from the Gulf of Mexico.

The combination of strong upper level winds from the southwest, strong low-level winds from the southeast and high levels of humidity will create an atmosphere primed to produce strong, supercell thunderstorms.

The National Weather Service Storm Prediction Center is cautioning that, “Strong tornadoes are possible today into tonight from east Texas into Mississippi, with the greatest threat expected between 2PM-8PM CDT.”

Population centers in the zone of greatest risk, 4 out of a possible 5 on the Storm Prediction Center’s scale, include Monroe and Alexandria, Louisiana.

In addition to the potential for tornado development, the strong line of storms will also produce damaging winds and heavy rain, capable of producing flash floods, particularly in Arkansas and parts of Mississippi and Alabama.

The storm system will lift northeast Sunday presenting a risk of strong to severe storms in the Appalachians and Mid-Atlantic. Violent weather is unlikely to be as widespread as Saturday, but some of Sunday’s storms may be intense.

“Damaging winds and a couple of tornadoes will be the primary hazards, but isolated hail may accompany the strongest [storms],” the Storm Prediction Center wrote.

Risk of severe thunderstorms Sunday, according to the National Weather Service Storm Prediction Center.

The Washington and Baltimore region are in the slight risk zone for severe storms on Sunday, with the best chance of storms into the evening and overnight hours. Very heavy rain — capable of producing pockets of flash flooding, damaging wind gusts, hail, and even an isolated, short-lived tornado cannot be ruled out.

Capital Weather Gang’s Jason Samenow contributed to this article.