Areas of fog are expected to develop across portions of Deep South Texas and the Rio Grande Valley overnight and into the early morning hours. Pockets of reduced visibility, generally 1 to 3 miles, with locally dense fog to a mile or less are likely. Should model guidance and observations from station data and webcams indicate rapid development of more widespread dense fog, a Dense Fog Advisory may be issued overnight for portions, or all of, the region. Use caution if traveling as visibility may change rapidly in a short amount of time. Use low beam headlights and leave extra distance between your vehicle and others on the road.