A major tornado outbreak featuring high-end, "violent" tornadoes is forecast for Alabama, Mississippi and Tennessee, with cities including Huntsville, Memphis and Nashville at risk of severe weather.
The big picture: The National Weather Service's Storm Prediction Center has issued a rare category 5 out of 5, "high risk" for severe weather, including potentially "violent" tornadoes, for northern Alabama, central and northern Mississippi, and western and middle Tennessee.
The details: The stage is set for a dangerous day in the South as warm, humid air flows north from the Gulf of Mexico, just as a pinwheeling area of low pressure at upper levels of the atmosphere moves in from the west. Fronts associated with these features will help trigger multiple rounds of severe thunderstorms.
- Winds blowing at different speeds and/or directions with height will ensure that storms have the propensity to rotate, putting large hail and tornadoes on the list of threats.
- The storms are forecast to first develop in central to northern Alabama and Mississippi early Thursday afternoon, with the threat shifting north into Tennessee this evening into the overnight hours.
- The Storm Prediction Center is warning residents of the affected areas to expect a few "long-tracked, violent tornadoes," which could be devastating if they strike populated areas.
- In addition to this threat, "Large to very large hail, and damaging winds to hurricane force also are possible over a broad area from the central Gulf Coast to the Ohio Valley and southern Appalachians," forecasters stated.
Between the lines: Severe weather in this region can be especially deadly due to the housing types that are prevalent here, including large numbers of mobile homes.
- With thick tree cover, hills and winding roads, tornadoes that can be wrapped in areas of heavy rain can be harder to spot than twisters in the Great Plains.
- Nighttime tornadoes are especially deadly, in part due to the difficulty of warning residents and ensuring they reach safe shelters in time. This severe thunderstorm outbreak is forecast to continue into the evening and possibly the overnight hours.
This story is developing. Please check back for updates.