|Posted: 7/27/2007 10:48 AM
DUBUQUE, Iowa (AP) — Large chunks of ice, one of
them reportedly about 50 pounds, fell from the sky in Iowa, smashing
through a woman's roof and tearing through nearby trees.
Authorities said they were unsure of the ice's origin
but have theorized that the chunks either fell from an airplane or
naturally accumulated high in the atmosphere — both rare occurrences.
"It sounded like a bomb," said Jan Kenkel, 78. She
said she was standing in her kitchen when an ice chunk crashed through her
roof early Thursday morning. "I jumped about a foot!"
She discovered a messy pile of insulation, bits of
ceiling, splintered wood and about 50 pounds of solid ice.
Neighbors Karle and Mary Beth Wigginton said they
heard a loud "whoosh" coming through the trees, discovering several large
chunks of ice in front of their home in this city in northwestern Iowa in
the country's Midwest.
"I could see where branches were shredded, which told
me it was definitely coming out of the sky," Karle Wigginton said.
He estimated the original chunk of ice was the size
of a basketball. "It was pure white," he said. "The main parts I picked up
were very smooth."
Elizabeth Cory, a spokeswoman for the Federal
Aviation Administration, said investigators would to try to determine the
source of the ice.
"It is very uncommon for something like this to come
from an aircraft," Cory said. "That is really unusual if it is pure white
ice, especially at this time of year."
Occasionally, aircraft latrines discharge contents at
altitude, resulting in chunks of descending ice. Airplanes also sometimes
accumulate ice on their edges in certain atmospheric conditions, including
high altitude and extreme moisture, said pilot Robert Grierson, manager of
the Dubuque Regional Airport.
The moisture involved in such a scenario could have
come from the tops of strong thunderstorms. However, Dubuque had clear
skies at the time the ice fell, said Andy Ervin, a meteorologist with the
National Weather Service in Davenport.
David Travis, a professor of geography and geology
and an associate dean at the University of Wisconsin-Whitewater, said it
is possible the ice could have been a megacryometeor — "similar to a
hailstone, but without the thunderstorm."
Travis is part of a research team that has documented
more than 50 possible megacryometeor cases during the past five years.
Some involve ice chunks the size of microwave ovens.
"It is hard to keep something like that suspended in
air without a thunderstorm," Travis said.
Most megacryometeor sightings have occurred in
coastal areas, where atmospheric turbulence helps keep ice suspended long
enough to grow into large chunks.
Travis' research team speculates the phenomenon could
be linked to global warming, suggesting that climate change might make the
tropopause portion of the atmosphere colder, moister and more
"But those don't typically happen in the summer
time," Travis said. "It seems like they are mostly associated with the
passage of passing cold fronts."
Original article: USA Today - Weather
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