A slushy mess is forecast to descend on the Interstate 95 corridor Wednesday, with heavy snow to the north and west. Here is what you need to know about when it's coming and what to expect.
When it's coming: Precipitation is forecast to start as rain late Tuesday night into Wednesday morning, turning into snow around daybreak at higher elevations west and north of Baltimore, and by mid-morning or midday closer to I-95. It is forecast to be out of the area by Wednesday afternoon or evening.
How much snow will fall: Given that rain is expected to mix in for longer in Baltimore and along I-95, an inch or two of slushy snow is expected to accumulate on grassy surfaces and cars. But snow accumulations are expected to increase sharply moving northwest from that corridor, with 3-6 inches in northern parts of Carroll, Baltimore and Harford counties and as much as 8 inches near the Mason-Dixon Line.
Travel impacts expected: Snow could have a hard time sticking to pavement, particularly in urban areas and close to the relatively warm waters of the Chesapeake Bay. Temperatures are forecast in the mid-30s in the evening hours. Travelers heading north, whether by land or by air, could face difficulty, with winter storm warnings in effect in eastern Pennsylvania, northern New Jersey and southern New England.
Road crews and airports on alert: The State Highway Administration briefed its winter crews Tuesday afternoon and planned to "stagger" their deployment onto state highways beginning late Tuesday night in Western Maryland, where a "significant amount of snow" is expected, said spokeswoman Kellie Boulware. Crews would start "patrolling and monitoring" roadways in the metro region beginning early Wednesday morning, she said – watching for areas where the expected rain turns to slush or snow. The SHA will also be watching for wet roads freezing over Wednesday night into Thanksgiving morning, she said. Airlines were gearing up for the possibility of cancelations and delays. A number of airlines have announced they will waive change fees for passengers flying through certain airports Wednesday, including Baltimore-Washington International Thurgood Marshall Airport, airport spokesman Jonathan Dean said. The airport's snow removal team will be prepared to treat and clear the airfield as needed, he said.
Uncertainty remains: Don't blame the meteorologists. Given that the line between rain and snow is forecast to fall somewhere over the region -- but that it is impossible to know exactly where -- it's possible that the region could see more rain, or more snow. The National Weather Service predicts slightly less than 50 percent chances that I-95 will see an inch or less of snow, and 15-20 percent chances it sees as much as 8 inches, for example.