A tornado watch and flash flood warning are in effect for the Baltimore region, with heavy rain and gusty winds expected through the night.
The tornado watch area includes all of central and southern Maryland and is effective through 2 a.m. Thursday. A tornado watch means conditions are favorable for tornado development but does not mean any have or will occur.
The Baltimore area is also under a flash-flood warning, coastal flood advisory and a wind advisory through early Thursday. Winds are expected from the south at 25-35 mph, with gusts up to 45-50 mph. Winds will shift to become westerly overnight.
A severe thunderstorm warning was in effect for Howard County, northern Anne Arundel County, Baltimore City and southwestern Baltimore County until 8:30 p.m.
Flooding and damaging wind gusts are a concern overnight, according to the National Weather Service's Baltimore/Washington forecast office. A cold front is causing the storms as it moves into unusually mild and moist air for January. Downtown Baltimore reached 73 degrees and BWI Marshall Airport reached 70 degrees by 3 p.m.
The weather service advises people to quickly move to higher ground if they see flooding and cautions against driving in areas where water covers the road, as most flash-flood deaths involve cars.
According to the Storm Prediction Center in College Park, hail up to half an inch in diameter, wind gusts to 75 mph and lightning are possible across the area if storms turn severe.
But local forecasters in the weather service's Baltimore/Washington office did not expect severe weather in earlier forecasts.
The cold front was still over Indiana on Wednesday afternoon, and when it reaches Maryland overnight could bring storms. Though they might not include thunder and lightning, damaging wind gusts and downpours are expected, according to forecast discussions.
The National Weather Service said tornadoes touched down in Sardis, Miss., and heavily damaged homes in Solsberry, Ind., wiping out power in the surrounding areas on Wednesday morning. At least one tornado was reported in the mid-section of Tennessee. In north Nashville, a man died when a tree fell on his garage apartment, according to Jeremy Heidt, spokesman for the Tennessee Emergency Management Agency.
Tornado watches extended from Mobile, Ala., across much of northern Georgia and eastern Tennessee into southeastern Virginia.
Baltimore Gas and Electric Co. is readying for possible storm-related outages. Customers are asked to report outages from mobile phones and devices through the mobile website at bge.com or by calling (877) 778-2222.
"Rain, combined with high wind and wind gusts, can weaken trees, bringing whole trees and tree limbs down onto power lines and other electric delivery equipment, and cause outages," Jeannette M. Mills, vice president and chief customer officer for BGE, said in a statement.
Local meteorologist "Eric the Red" writes that "the heavy-duty storms" forming closer to the cold front are not expected until after 10 p.m. in the Baltimore area.
Reuters contributed to this report. Have a weather question? E-mail me at email@example.com or tweet to @MdWeather.