Snow possible tonight after heavy rain, potential flooding

Heavy rains throughout the day and into the night Wednesday will create the potential for flooding in the Baltimore area, and forecasters say a small amount of snow is possible overnight.

As cold air from the north and west filters in to the Baltimore region, temperatures will drop in the evening, said Brian Lasorsa, meteorologist at the National Weather Service in Sterling, Va.

An earlier winter weather advisory, calling for 1-2 inches of snow in the city, was canceled after 2:30 p.m.

The advisory for the northern half of Baltimore County and Carroll, Harford, Howard and Montgomery counties was lifted by 10 p.m. Light snow was still a possibility as colder air moved into those counties, the weather service said, but accumulations would be less than one inch.

Slightly slushy conditions are possible for the Thursday morning commute in parts of Western Maryland, particularly in Frederick County where a winter weather advisory remained in effect until 1 a.m. Thursday, the National Weather Service said.

There will be wet roadways closer to the city from the rain, and bridges and overpasses may have some slick spots.

A flood warning is in effect until 1:30 a.m. Thursday for much of the I-95 corridor, including the District of Columbia, northern Virginia and Baltimore City and Anne Arundel, Harford, Montgomery, Prince George's, Howard and Baltimore counties. Rainfall amounts of 1.5-2.5 inches had already been reported in these counties by 10 p.m.

Wednesday evening, the low temperature will be around 33, with northwest winds about 21 miles per hour.

"Wind gusts could be over 40 mph overnight," Lasorsa said, enough to cause minor damage from fallen tree limbs.

Meanwhile Baltimore City declared the first Code Blue alert of the season Wednesday night, triggering extended hours at homeless shelters and other cold weather outreach.

Temperatures will warm up again Thursday morning, Lasorsa said, and the precipitation may be gone in most areas by rush hour.

"Any problems early in the morning should go away," Lasorsa said.

Thursday is expected to be mostly sunny, with a high near 43 degrees and west winds of 8 to 15 miles per hour.

Thursday night is expected to be mostly clear, with a low around 32 and light, variable winds.