A concentrated area of blow-downs near Clary Lake in Jefferson was most likely caused by a microburst during thunderstorms the night of Sept. 11, according to Mike Ekster, a senior forecaster for the National Weather Service in Gray.
According to the glossary at Weather.gov, a microburst is “a convective downdraft with an affected outflow area of less than 2½ miles wide and peak winds lasting less than 5 minutes. Microbursts may induce dangerous horizontal/vertical wind shears, which can adversely affect aircraft performance and cause property damage.”
The area of Clary Lake in Jefferson and Whitefield was hit hard in the storm, with dozens of trees and limbs coming down in the storm and some taking power lines with them.
One very localized area, just off Duncan Road and near the shore of Clary Lake, was hit especially hard with at least seven softwood trees and three hardwood trees, all with trunks around one foot in diameter or larger, being blown down or broken off in the same direction during the storm.
“There’s definitely a line where very strong wind came through and took a lot of trees down, uprooted trees. It did quite a bit of damage in a localized area,” said Jefferson Fire Chief Walter Morris.
A number of the trees remained rooted in the ground but snapped off either near the middle or top of the trunk, with most of the limbs torn off.
At least one tree appeared to have struck a nearby one-story building and caused minor damage.
No one from the National Weather Service has been to the site to confirm with certainty whether it was a microburst, Ekster said, but “it most likely was a microburst … because it seems to fit the criteria.”
Since the trees were all blown down in a single direction, it was not likely caused by a tornado, which would have knocked the trees down in all different directions, Ekster said.
Along with the winds, “it was wicked lightning, and hail, quite a bit of hail,” Morris said.
Morris said around 18 firefighters were out last night from 8:30 p.m. to midnight dealing with the result of the storms, working hard to get the roads open and maintain safety around the wires.
North Clary Road, Sennett Road (Senott Road, in Whitefield), Duncan Road, Shovelhead Drive, and Old Madden Road were all closed for a while because of trees and wires down, but all had at least one lane open by midnight, Morris said.
The morning of Sept. 12, Sennett/Senott Road was closed again by the fire departments of both Jefferson and Whitefield as Central Maine Power ran new power lines, Morris said.
Gail Rice, a spokesperson for Central Maine Power, said the peak time of outages for Lincoln County from the thunderstorms the night of Sept. 11 was just before 3 a.m., with just under 2400 customer accounts affected.
As of 3:12 p.m. on Sept. 12, the number of outages was down to 267 accounts, some of which were new outages from thunderstorms that afternoon. The outages were mostly within the area of Boothbay and Edgecomb, Rice said.
“We do expect this to get wrapped up by later this afternoon or this evening,” Rice said.