An unusual “microburst” weather event struck the heart of the main campus Monday night at about 7:30 p.m., topping and seriously damaging several trees in the front lawn area. Other areas of the campus were plagued by broken limbs and other debris from the event. There was also a power outage in the area – a contributing factor to which was the toppling of a utility pole at the corner of Washington and Main streets.
“I just did not want anybody to think we were out there willy-nilly cutting down trees all over campus,” said David Barnett, the university’s chief financial officer and risk assessment guru, as workers with chainsaws and other equipment cut up the broken and damaged trees. “We only removed trees that could not be saved.”
The eight trees affected, mostly hemlocks, were either on the ground, badly broken at the trunk near the top of the tree or leaning dangerously over the sidewalk and roadway along Boulevard in front of Wilkes Hall. Greg Hutson, owner of the landscaping company that Brenau employs to help maintain the historic campus, inspected all the trees in the front campus area and consulted with university officials about which trees could be saved and which had to be removed.
Although the event and the swarms of workmen along Boulevard busily removing debris was eerily reminiscent of the two tornados that damaged the area in 1903 and 1936, this was no tornado.
A microburst is an intense down-draft that occurs within a thunderstorm that can last from a few seconds to several minutes and can bring high winds that can knock over fully grown trees – especially, as in the case of the Monday event – if accompanied by torrential rains that loosened around the tree’s roots.
And now for the rest of the story….
We know this because Brenau Office of Communications & Publications is in the process of developing an “experts data base” from faculty and staff because occasionally the media and others need some ’splaining to be done. This is just such an occasion. We turn to our resident weather expert, Dr. Rudi Kieffer, and ask him what happened:
“What occurred in Gainesville was a typical convective thunderstorm. This kind is quite common in the summer. Humidity can be thought of as energy. The water vapor in the atmosphere condenses when clouds form, and this process releases heat. We had a high of 85 degrees, and the rise of air over the hot city surfaces was amplified by release of heat energy from condensation. While this storm was small in diameter (probably less than 10 square miles), it built up quite strongly. At the peak of the event, winds gusted to 39 mph with quick, heavy downpours. Several trees were brought down on the Brenau Campus, along with a power pole at Washington and Main streets.
“This is not anywhere near the power of the 1936 tornado, whose winds speeds beyond 100 mph knocked a huge hole into the ceiling of Pearce Auditorium and removed dozens of trees. But we’re still fortunate that no injuries were reported, since falling tree limbs are dangerous in any storm. Overall, the Aug. 18 thunderstorm was heavy but not unusual, because north Georgia is an area where intense heat from the sun combines with a steady influx of moisture from the Gulf of Mexico at this time of the year. Another month of summer lies ahead, so we’re likely to see more isolated thunderstorms of this kind. “