LOWELL — Vermont’s largest electric utility says snow stuck to turbine blades caused a roaring sound that drew noise complaints shortly after the Lowell Mountain turbines started operating.

At least 21 neighbors complained about the noise, which began on the morning of Nov. 3 and lasted into Nov. 4.

The neighbors complained to the Vermont Department of Public Service.

GMP spokesman Robert Dostis said the excess noise was caused by the weather conditions.

Dostis said neighbors should call the utility when they have noise complaints so technicians can modify the operation of the turbines or shut them down.

GMP just completed construction of its 21-turbine project on Lowell Mountain.