Microburst on Westport Island?
Wind: the island nemesis
There were no emergency management alerts last Friday: no more than an expectation of passing thunderstorms. And — other than a night without electrical power — for most on the Island, Mother Nature served only a brief pounding of much-needed rain, a cooling wind, and a few claps of thunder.
For a half mile along the western shore of Westport — roughly from the Ferry Landing to 289 Main Road — August 3 brought a tad more “weather.” Donna Curry says it’s the worst damage she’s experienced from any storm in her 17 years on the Island. She had horizontal sheets of rain pushing into her attic vent, and she’ll be cleaning uprooted and snapped trees and debris from her yard for weeks to come.
According to the Weather Channel Storm Encyclopedia, a severe thunderstorm produces one of the following: hail of 3/4 inch or more in diameter; tornadoes; or wind of 58 miles an hour or more. The National Weather Service estimates that trees are uprooted or snapped with 58- to 72-mile per hour winds — so it’s fair to say that the winds that struck the Curry property and nearby were in excess of 58 mph. And, a “microburst”, which is a downburst confined to an area less than 2.5 miles in diameter, is among the most devastating expressions of a severe thunderstorm. A downburst is defined as “a sudden vertical drop of air that produces strong wind shear.” Looks like a half mile of wind-related destruction meets the definition of microburst…
The only other Lincoln County storm reports to Portland’s National Weather Service station on August 3 were in Boothbay. The winds were reported to be from the southwest.
Sometime around 7:30 or 8 p.m., Westport Island’s thunderstorm microburst “warmed up” at the Ferry Landing where it snapped a broad pine next to the Wright house and lifted a stand of pine from its rock base on the point. The wind sped onto the Curry property with increased strength where more than a dozen 20- to 70- foot hardwoods and pines were leveled. The top “feathers” of branches brushed the side of Donna’s house and broke off on her deck and roof. Part of the stairs to her dock were crushed, and she ended up with a stray orange kayak on her shore that she would like to return to its rightful owner.