Southern states at risk for more severe weather

>>> and now to the series of monstrous storms crossing the country. we have been tracking this for days. the national weather service today issued a rare high risk warning of tornadoes, hail, flash flooding , and dangerous storms for georgia, alabama , mississippi, and warned that severe weather could strike 21 states down from the great lakes to the atlantic coast . we have an active situation tonight. this storm has claimed at least 30 lives so far. weather channel 's julie martin is in poplar bluff , missouri. with the latest, julie, good evening.

>> reporter: good evening, brian. the biggest flooding threat remains in poplar bluff tonight. if the river breaks -- levee breaks holding back the black river , as many as 7,000 residents will be impacted. it's one community of many tonight bracing for the worst. it's a fifth day of rain and the swollen black river continues to breach its levees.

>> everything is soaked.

>> reporter: and there's four feet of water inside steve's home.

>> it's terrible, just awful. and so many families here. you know, have been stricken, who don't have flood insurance . i mean, it's awful. you know, steve lost everything he has. he's worked all his life.

>> this is a dangerous storm.

>> reporter: alabama hard-hit today, at least 12 dead. power lines and trees are down. flash flooding and extensive damage reported. officials reported dozens of tornado sightings in alabama and mississippi and tennessee. in texas, a tornado formed during live tv coverage.

>> we got a tornado!

>> reporter: major flooding is now pushing the banks of more than 50 rivers and streams . huge sections of the midwest and south are experiencing the brutal side of spring. while the system will move offshore, it will take far longer to rebuild the lives it ruined.

>> nothing i can do but start over again.

>> reporter: and right now, we do have an active tornado system moving through alabama . we'll continue to follow that for you. as far as the bigger weather pattern, conditions will be impriving late thursday into friday, but not in much time for people to catch their breath as the next major storm system is scheduled to arrive saturday.

>> an active situation tonight.