(CNN Image) Posted: Mar 15, 2021 / 07:51 PM EST (CNN) — An outbreak of severe weather will threaten more than 40 million people this week from the southern Plains through the Southeast — with tornadoes, large hail, damaging winds and heavy rain all possible. “The potential is there for significant severe weather,” said Meteorologist Jason Holmes at the National Weather Service (NWS) office in Birmingham, Alabama. Long-track tornadoes are possible given the forecast weather pattern and environmental conditions, according to the NWS office in Mobile, Alabama. These types of tornadoes are ones that consistently remain on the ground for an extended period of time, unlike a typical one which could be on the ground for just minutes.