ABC News(DALLAS) — A very dangerous weekend lies ahead for much of the South — with especially severe storms expected in Louisiana, Arkansas and Mississippi on Saturday.The new storm organized Saturday morning and was moving across Texas. In addition to a widespread severe weather outbreak from Texas to parts of the eastern U.S., this storm will likely bring an outbreak of tornadoes across parts of the southern U.S. on Saturday. The severe weather outbreak already began Saturday morning in parts of the South with reports of large hail in Texas, Louisiana and Mississippi.A tornado watch was issued for extreme southwest Texas until 9 a.m. local time Saturday morning. A severe thunderstorm watch was issued for parts of western Texas through 9 a.m. Flood alerts are also being issued for parts of the southern U.S. due to torrential rainfall.Radar is showing quite a bit of storm activity developing Saturday morning from Texas to Alabama, with the most intense storms in western Texas and near the Arkansas-Louisiana-Texas region.Severe storms will develop later Saturday in eastern Texas, Louisiana and western Mississippi that will likely tap into strong wind shear and develop dangerous supercells in the afternoon hours. The High Resolution Rapid Refresh model is showing numerous discrete supercells developing during this time frame and the potential for strong tornadoes. The intense thunderstorms will move across this region beginning in the afternoon and last into the evening hours.There is a moderate risk for severe weather from Lufkin, Texas, to Jackson, Mississippi, including much of northern Louisiana. In the moderate risk region, dangerous, long-track tornadoes are possible. Additionally, destructive straight-line winds and very large hail are possible from eastern Texas to western Alabama.Intense thunderstorms will continue through the overnight hours in parts of this region. There is a possibility of ongoing severe weather early Sunday morning, with night-time tornadoes and destructive winds.On Sunday morning, storms will congeal into a line that will likely stretch from the Florida Panhandle to Ohio. The main threat will be straight-line, damaging winds. However, embedded tornadoes could develop in the line of thunderstorms.The line of storms will impact the Appalachian Mountains on Sunday evening as they begin to lose their severe potential. Nonetheless, numerous severe thunderstorms, with damaging winds, large hail and a couple of tornadoes, are possible as the storms move through the region.There is an enhanced risk for severe weather on Sunday from Georgia to Ohio, including Atlanta; Charlotte; and Charleston, West Virginia. Damaging winds, a few tornadoes and large hail are possible in the risk region.In addition to the severe weather threat, storms will bring torrential rainfall over parts of Louisiana, Arkansas and Mississippi. Rainfall over 4 inches is possible in that region, which makes flash flooding a concern with the ongoing storms this weekend.Copyright © 2019, ABC Radio. All rights reserved.