WESLACO – With a dense fog hitting the Rio Grande Valley, truck drivers are warning people the danger fog can cause.

Encarnacion Ramirez, a truck driver on his way to Tennessee, says there are many dangers on the roads.

"Black ice, traffic. Traffic is a big thing. Heavy rain, snow," said Ramirez.

One of these dangers is dense fog.

Ramirez said he knows other truck drivers who have become victims of the dangers fog can bring.

"It was night, like around this time. My friend was on his way down here and there was a tanker parked on the side of the road but he didn't see him so he hit him and he flipped over," said Ramirez.

When the fog gets too thick, Ramirez said, its protocol to pull over and wait it out. This can cause issues when it comes to making deliveries on time.

"We have to call our dispatcher to let them know and pretty much they have to reschedule," said Ramirez.

More fog is expected for the Valley throughout the week.

"Fog is formed when the temperature and the dew points are equal that means the air is 100 percent saturated,” explained KRGV Chief Meteorologist Tim Smith. “Unless there is something to mix it out unless there's some good wind or something to dry the air out you are going to get fog and in the winter night the nights are longer so the temperatures come down quicker.”

Smith says the lower the visibility the more cautious drivers need to be.

"Once it gets under a mile it starts to get tricky, cause a mile is not very far, but you get down to a half mile or less, then you really have to be careful at half-mile of visibility. You could drop off to a quarter or zero really quickly, and next thing you know, you’re stuck in the middle of visibility that is nothing and you could run into somebody so easily," said Smith.