Supercell thunderstorms could produced multiple long-lived EF3+ tornadoes today in the mid-Mississippi and lower Ohio valleys. Tornadoes, destructive straight-line winds and damaging hail will also impact a much larger area of the Midwest and South.

These are the most dire outlooks for severe weather NOAA's Storm Prediction Center issues. Here's what they mean and what you should know.

A brief but brutal EF2 tornado tore through Grand Prairie, Louisiana, flipping an RV, shredding a home and snapping trees in half. The National Weather Service confirmed its destructive path, which skirted near the small village of Palmetto, using radar and survey data.

Double-digit rainfall totals are forecast, prompting the National Weather Service to issue flood watches from Wednesday into Saturday. Serious flash flooding and flooding of rivers, creeks and streams can be expected.

Severe weather including storms, flooding and possible tornadoes brought weather warnings and damage across parts of the South and Midwest Sunday.