Severe flooding in South Texas has left at least four people dead and forced emergency crews to rescue hundreds of people from rising waters. State officials say the Rio Grande Valley endured more than half of a year's worth of rain within the span of 48 hours last week, leading to submerged roads and waterlogged vehicles.

At least three people died in southern Texas and one across the border in Mexico after as much as 20 inches of rain fell in parts of the Rio Grande Valley, stranding motorists and causing widespread destruction.

Another round of scattered storms overnight into Thursday morning. Then heavier, more widespread showers/storms Friday into Saturday, with a flood threat by the weekend.