Fog won’t be as thick Wednesday morning

Patches of fog will continue Wednesday morning, reducing visibility in some places to just under a mile, but it will not be as heavy as it was Tuesday morning, according to the National Weather Service.

The fog will linger until about 10 a.m. at the latest, with bigger patches in rural and sheltered areas, said meteorologist Lamont Bain at the weather service’s Fort Worth office.

Thick fog blanketed North Texas on Tuesday morning, causing flight delays and headaches for commuters. Visibility was down to less than a quarter-mile in many counties, including Tarrant County.

Decreased visibility caused several MedStar ambulance crews to start calling in early Tuesday, requesting permission to drive without lights or sirens, MedStar spokesman Matt Zavadsky said.

Because of the fog, flashing ambulance lights would have reflected inside the vehicles, a distraction for the drivers, he said.

If weather conditions make it unsafe for ambulance drivers to operate without lights, they cannot use sirens, either, because the law requires both.

“We do not operate with sirens only,” he said. “We have to have both the lights and the sirens on because it’s safe and because it’s the law.”

Dense fog caused trouble in the skies, too.

Federal Aviation Administration officials issued a ground stop at Dallas/Fort Worth Airport, which slowed the traffic destined for DFW by holding planes on the ground at their departure airports.

By noon Tuesday, 139 flights were canceled and 157 were delayed into and out of the airport, NBC 5 reported.

Daytime temperatures Wednesday and Thursday should be in the 60s, with morning temperatures in the low 50s. Thursday brings a 20 percent chance of rain.

Staff writer Domingo Ramirez Jr. contributed to this report.

This story was originally published December 9, 2014 at 8:13 AM with the headline "Fog won’t be as thick Wednesday morning."