LOS ANGELES - A significant tornado outbreak in the South on Wednesday is expected to continue with numerous strong, potentially violent tornadoes likely to impact the region into Thursday."Tornadoes are not all that rare in the Southeast in March, but outbreaks where so many tornadoes are expected to occur in a one- or two-day timeframe is something we don't see every year," Bill Bunting, the chief of forecast operations at the National Weather Service's Storm Prediction Center (SPC), told FOX Television stations.The SPC issued its highest threat level forecast category for severe weather — "high risk" — from parts of the lower-Mississippi Valley into Alabama.