Perhaps you know the T-Bone Walker tune "Call It Stormy Monday," but today is foggy Thursday, and it's going to stay that way, at least through the morning hours.
The National Weather Service in Fort Worth has issued a fog advisory, which means visibility will be cut to less than a quarter-mile in most places.
Commuters could see for themselves that they were in the soup early Thursday, but just how foggy was it?
"Ninety-five percent of the Metroplex is at a quarter-mile or less," said Eric Martello, weather service meteorologist.
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D/FW Airport was reporting 1/8 of a mile, according to weather service data.
"As a result we have about 40 flights canceled so far," said David Magaña, airport spokesman. "But four of those are due to weather issues in other cities."
He mentioned Las Vegas, where the National Weather Service measured 3.6 inches of snow overnight.
It was the heaviest snowfall in nearly three decades in Las Vegas and it resulted in the cancellation of all flights in and out of McCarran International Airport, according to the Associated Press.
Meanwhile, Magaña said at 9:30 a.m. that there were "no significant delays to report" at D/FW Airport.
"Most of our flights are getting in and out just fine," he said.
Airport officials, however, urged travelers to check with their airlines to determine if their flights were affected.
Heavy fog arrived Wednesday after a blast of arctic air delivered freezing temperatures to the Metroplex on Sunday.
On Tuesday, however, warm southerly winds pushed temperatures back up to above freezing, and also filled the region with moist air from the Gulf of Mexico.
The warm, moist air collided with cold, dry air, which created condensation in the form of fog.
"We just had the right conditions for it," said Jessica Schultz, another weather service meteorologist. "The atmosphere was not mixed well, so we ended up with a lot of fog."
The dense fog was expected to last through noon, and possibly longer, Schultz said.
"It's likely that some fog will still be around, even in the afternoon hours," she said. "So it's also likely to be a cloudy day with a lot of drizzle and a high of 66."
Fort Worth police responded to 16 accidents before 8:30 a.m., according to records. Five were listed as major, one was a hit-and-run and 10 were listed as minor. That's not an unusual amount for a given day and it was unclear if fog contributed to any of them.
However, weather service officials urged motorists to heed the dense fog warning.
"Leave some extra distance ahead of you," said Schultz. "Also, the roads are sill slippery because of the extra moisture on the road, so folks should slow down."