The boy’s father was also struck by the tree, the police said, but his injuries were not life-threatening.
On Monday, Joshua Davis, 15, from Chevy Chase, was killed while riding his bicycle when a falling tree struck him, the Montgomery County police said.
Four of the six tornadoes confirmed in the region were reported on Monday, the National Weather Service said. They occurred in Baltimore, Baltimore County, Howard County and St. Mary’s County.
St. Mary’s County was also the site of one of the two tornadoes confirmed after Thursday’s storms. The other tornado spawned by Thursday’s storms occurred in Montgomery County and was notable for the length of its track, which the weather service said was 17.3 miles long.
It extended across the county, in a generally easterly direction from near Turkey Foot Road and Jones Lane in the North Potomac area to Spencerville and Burtonsville.
After causing tree damage in North Potomac, it headed toward northern Rockville and then the Norbeck and Aspen Hill area, the weather service said.
Near the Manor Country Club golf course, the weather service said, 30 trees were uprooted. Many homes along the path were damaged by falling trees, but no injuries were reported.
Following a path about 150 yards wide at the maximum, with peak winds of 75 mph, the tornado also knocked down some trees near the eastern end of its track, the weather service said. Like the other tornadoes, it was rated at EF-0, the lowest intensity on the scale used to classify twisters.
Another trail of storm damage in Montgomery County just south of the long tornado trail appeared not to be the direct result of a tornado, the weather service said.
Trees were toppled along a seven-mile path through south Rockville and Glenmont, but the damage was described as the consequence of straight-line winds from an outflow from the tornado.