UVALDE, Texas -- Slow-moving storms with heavy rain were drenching a large swath of South Texas on Wednesday, spawning a tornado in San Antonio a day after downpours washed out roads and farmland and led to dozens of high-water rescues in the region.

The National Weather Service said a tornado touched down in the northwestern part of San Antonio near Interstate 10.

Videos posted on social media showed what appeared to be a small twister.