Road crews are readying for a storm expected to bring 6 inches or more across the Baltimore region Thursday, potentially the biggest snowfall of a winter season many are already tired of.

Though temperatures surged into the mid-40s Wednesday amid rain showers, a cold front is forecast to bring back frigid temperatures and wintry precipitation overnight through Thursday.


Rain is forecast to turn to sleet and then snow after midnight as temperatures dip below freezing. The National Weather Service is forecasting 6 to 8 inches of snow along Interstate 95 and 8 to 10 inches north and west of that.

How much snow falls depends on how quickly the changeover to snow occurs and how intensely bands of snowfall develop, with forecasters acknowledging chances for as little as a few inches or as much as a foot. Temperatures are forecast to drop to the upper 20s by early Thursday morning.

A winter storm warning is in effect from 10 p.m. Wednesday through 7 p.m. Thursday.

The State Highway Administration and other transportation officials are again urging drivers to stay off the roads during heavy snowfall. Because of Wednesday's rain, crews are unable to pre-treat roadways with a brine solution that can otherwise prevent or delay snow from covering roads.

"If you do choose to drive, be sure your vehicle can maneuver in the snow. Just one abandoned car can create a traffic jam that impacts everyone, including our plow trucks," SHA Administrator Melinda B. Peters said in a statement.

Baltimore City officials were gathering salt Wednesday after recent ice storms "depleted" stores, city Transportation Director William Johnson said. The city is activating its snow emergency center at midnight and has bolstered salt stores to hold 3,500 tons by Wednesday afternoon, spokeswoman Kathy Dominick said.

"Traveling is going to be very difficult," Johnson said. "We're expecting some of the heaviest snow periods to occur after 3 o'clock in the morning and to go well into the day tomorrow. I would encourage all motorists to proceed with caution and plan your schedule accordingly."

Winter storm warnings stretch from northern Texas along the Mississippi and Ohio valleys to the mid-Atlantic, affecting some 57 million people, according to the weather service.

It hasn't even been a year since Baltimore's last significant March snowfall -- 8.1 inches fell on St. Patrick's Day and the preceding day in 2014.

But if this storm can surpass that total, it could be Baltimore's biggest March snowstorm in decades. A foot fell across the region in a March 1993 storm.

After the snow ends, a spell of more unseasonably frigid cold is ahead.

Temperatures are expected to drop into the single digits by early Friday morning, reaching only the mid-20s that afternoon. Sunny skies are forecast.

After lows in the teens Saturday morning, milder but still colder-than-normal weather is forecast for the weekend, with highs around 40 degrees and partly cloudy skies.

Baltimore Sun reporter Yvonne Wenger contributed to this article.