Microburst visits island in the Bush Alaska
By TIM MOWRY, Staff Writer
October 18, 2003
When something strange happens in Bush Alaska, the event often has a way of
generating a life of its own.
Such was the case about a month and a half ago in the Yukon River village of Ruby when word--and then a videotape--began circulating about a swath of trees the size of a football field, some with trunks as big as 55-gallon barrels, that had mysteriously snapped off on an island nine miles upstream.
The 150 or so residents in the remote village 200 miles west of Fairbanks immediately began speculating what caused it.
"There were different theories," said local resident Pat McCarty, who inspected the site twice.
While some residents thought it was caused by wind, others suggested that a meteor, or even a UFO, was responsible for the destruction, said McCarty.
"It's kind of strange the way the trees are all standing and all of a sudden there are no trees, they're all lying down," said McCarty, 50, who has lived in Ruby his entire life and never seen anything like it. "It's like a gigantic helicopter came down, hovered, knocked the trees flat and on the way out clipped some other trees."
Dozens of giant white spruce trees were completely uprooted and large cottonwood trees were snapped like toothpicks 10 to 20 feet up, said McCarty.
"These were some big trees," he said. "They were just knocked down."
Nobody knows when it happened. A pilot who flew over the area at the start of the moose hunting season in September was the first to notice the hole in the woods on what's called Ninemile Island.
"One of the pilots came in asking if there was a plane wreck up there," said McCarty.
Mike Spindler, refuge manager for the Nowitna National Wildlife Refuge in the neighboring village of Galena, 50 miles downstream of Ruby, heard the rumors flying around earlier this week.
"The first thing we heard is they had a video of a meteor falling," Spindler said.
But when Spindler heard the location and description of the area, he began to put two and two together. Spindler had flown over the area on Sept. 9 with the refuge's fire management officer, forester Bob Lambrecht, and Lambrecht had spotted the clearing.
"He looked down and said, 'Oh, that's a microburst,'" recalled Spindler.
Microbursts are rare weather phenomena that produce tornado-force winds in an isolated area during a thunderstorm by creating a rapid, downward burst of air that spreads out and picks up even more speed when it hits the ground, according to meteorologist Tim Shy at the National Weather Service in Fairbanks.
Precipitation pushes against the air and acts like a piston, pushing air downward. At the same time, dry air evaporates the precipitation and cools the air, making it more dense and creating more velocity. The air hits the ground at 50 to 60 mph and spreads in a circular pattern like a cup of water being poured onto the floor, Shy said. As it spreads, the wind speed increases to 100 mph or more.
A microburst typically covers a very short distance in a very short time, Shy said.
While Spindler and Lambrecht didn't land to inspect the site, they said the devastation was obvious from the air.
"I've flown in this area for 14 years and seen blowdowns but I've never seen an intensively cleared area like this," said Spindler. "There wasn't anything standing in that area."
Ruby school principal Tim Stathis went to the site with McCarty to videotape the scene.
"It's quite astounding," said Stathis, who sent the video he took to KTVF channel 11 in Fairbanks, as well as the University of Alaska Fairbanks Geophysical Institute. "There are dozens of trees snapped off 10 to 20 feet up and a whole bunch of others uprooted. It's only in one isolated spot. There's nothing in the near vicinity that's knocked down."
When Stathis aired his video in the village, about 30 people showed up to watch it.
"No one had ever seen anything like it," Stathis said.
Buck Sharpton, a professor of remote sensing at the University of Alaska Fairbanks who saw the Stathis video, also said it appeared to be the work of a microburst.
"I spent a lot of time in Texas and am familiar with the signature a microburst leaves," said Sharpton. "It sure did look like something like that. It was a major event."
But the videotape also reinforced some peoples' belief that a UFO was responsible for the damage, Stathis said.
While that may sound far-fetched, McCarty acknowledged that some residents in the village think they have seen UFOs in the area in past years.
"Over the years, there's been sightings of strange lights around," said McCarty. "I've seen some strange lights hovering over trees kind of like a helicopter.
"Those kinds of lights have been spotted by other people in other villages, too," he said. "It makes you wonder."
Chances are microbursts are far more common than they are reported in Alaska, Shy said. Nobody sees them in most parts of the state unless they happen to fly over them because the state is so big. The weather in Alaska in June and July provides the perfect recipe for microbursts, Shy said.
"Alaska has all the precursor conditions for a microburst occurrence," he said. "We have a dry air mass, we have thunderstorms that are high-based and we tend to evaporate a lot of precipitation as it's coming down."
Staff writer Tim Mowry can be reached at firstname.lastname@example.org or 459-7587.