Forecasters issued a series of tornado warnings in several states Monday on what forecasters said could be a day of dangerous weather in the Deep South.

Radar showed possible twisters as a weather system moved across the region, forecasters said, prompting tornado warnings in east Texas, Louisiana, and Mississippi as storms moved eastward, the National Weather Service said.

There were no immediate reports of touchdowns or damage, but the weather service said the threat of severe weather would continue all day as a cold front mixed with warmer air.

About 1 million people live in an area of northeastern Louisiana and southwestern Mississippi that had a moderate chance of dangerous weather, forecasters said. A tornado watch was issued from east Texas through Louisiana into central Mississippi and southern Arkansas.

Forecasters said a lesser threat extended into Alabama, western Georgia, the western Florida Panhandle and Tennessee as storms moved eastward.

Several school systems in Alabama and Mississippi announced plans to dismiss students early and canceled afternoon events and activities as a precaution since storms could be moving through around usual dismissal times.

Forecasters said tornadoes, hail and winds blowing at 70 mph (112 kph) posed the greatest threat as a cold front moved across the region in an easterly direction. Storms that are predicted to begin in the west could last until early Tuesday in the eastern, forecasters said.