Weather's recipe right for twisters
Staff writer
Sunday's devastating tornadoes in Ibaraki and
Tochigi prefectures were caused by a rare situation attributed in part
to a winter that went on for some weeks longer than normal, and a recent
sharp rise in surface temperatures, experts said Monday.
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| Housecleaning: People clear debris Monday from a building whose roof was torn off by a tornado in Tsukuba, Ibaraki Prefecture, the previous day. KYODO |
One person died and several were injured in the twisters.
"Tornadoes rarely occur in this season," said
Yasushi Fujiyoshi, professor at Hokkaido University. "It is rare in the
first place for cold air to form in the troposphere in May."
Fujiyoshi said such frigid air is more a feature
of the fall and the extended period of freezing weather earlier this
year helped create the atmospheric conditions conducive to
tornado-formation.
He also warned there is a possibility that
massive, unstable cumulonimbus cells, the main source of thunder, hail
and tornadoes, will be more common this year, but added this does not
necessarily spell more tornadoes, because there are many other
conditions affecting wind movements that help spawn twisters.
Experts noted that tornadoes form during unstable atmospheric conditions when thunderclouds form quickly.
On Sunday, with the air at minus 21 degrees
at an altitude of 5,500 meters, a warm air mass moved in over an area
stretching from the Tohoku to the Tokai regions. This created conditions
for thunderclouds to form, bringing with them heavy rain and hail.
Unlike in the U.S., tornadoes in Japan are more
common between August and October, during the main typhoon season, said
Takeo Tanaka, head of the weather information office at the
Meteorological Agency. But he added that the mechanism of how and why
tornados form has yet to be pinpointed.
Whatever theories meteorologists may have,
residents living in the affected areas in Tsukuba, Ibaraki Prefecture,
and Moka, Tochigi Prefecture, face tough challenges ahead.
On Monday morning, they were busy clearing debris
left in the storm's aftermath, including flipped cars and roofless and
devastated structures.
Yoshio Asano, 51, who lives with his
81-year-old mother, said they spent Sunday night in a room that survived
the twister. Their house was partially damaged.
"We felt scared because we were left without
electricity," he said. "But we were prepared. We had emergency
flashlights and batteries because of the March 11 earthquake last year."
Even so, Asano said he is at a loss when he
thinks about what to do, where to start, and what's going to be waiting
for him as he tries to rebuild his life.
For him and others left to pick up the pieces,
there is the reality that the power of Mother Nature if a force to be
reckoned with.
"A blame game won't get us anywhere," Yasushi
Izumi, a 38-year-old office worker who lives in the area, said as he
cleared shattered glass and other debris at his home.
Information from Kyodo added
