Heavy fog across much of central Maryland caused traffic tie-ups and airline delays and made the air feel like a wet sponge. But Jason Hume, 6, and Russell Lester, 9, of Roland Park, couldn't let last week's snow melt away without one more sledding expedition.
"We're about to go sliding down the hills at the country club," said Jason, holding a red sled shaped like an inner tube.
His friend Russell stopped to put on a ski mask, prompting Jason to ask: "What are you waiting for, Christmas?"
Elsewhere, few people were having as much fun.
On Interstate 95 in northeast Maryland, heavy fog slowed drivers down to 35 mph, and state police at the Kennedy Highway barracks said a minor bus accident in the early afternoon caused a 10-mile backup on southbound I-95 as drivers crept along in the fog.
Sgt. Charles Pertain of the North East barracks said he had been warning drivers to use caution and to stay off the roads if possible.
"All it takes is to be in the wrong place at the wrong time," Sergeant Pertain said. "If you have to drive, drive with your lights on and clean your lights. Sometimes you can't even see [dirty] lights until it's too late."
While central Maryland was battling the fog, however, the far western part of the state had little fog and somewhat warmer temperatures -- almost 60 in Garrett County -- while the Eastern Shore sat under a light haze.
Ken Shaver, a forecaster for the National Weather Service at BWI, where visibility dwindled to about one-sixteenth of a mile at 3 p.m., expected the fog to linger in the northeastern part of the state last night and early this morning.
Snow cover makes the ground cold, Mr. Shaver said, and when a layer of moisture-laden air comes near the ground, it cools off and condenses into fog. A layer of warm air above helps trap the fog near the ground.
The fog caused minor delays during the afternoon for most airlines operating out of BWI.
Mary K. O'Neil, a spokeswoman for American Airlines, said the airport had minimal visibility about 5 p.m., causing 20- to 30-minute delays for most flights. Flights heading toward the Midwest also were delayed because of freezing rain, she said.
But by 8:30 p.m., visibility had increased to one-eighth of a mile and planes were moving smoothly, a BWI spokesman said. State police later reported improving conditions, although the fog continued to plague some areas.
"I can't see out the front door," said Sgt. Ron Mosco in Westminster. "In spots, it's real bad."
Conditions are expected to improve today, with warm air from the west expected to push into the Baltimore area today for a high of 60.
Showers are likely tomorrow, with temperatures in the 50s.