Hallo Johan,
I am sending a photo that Neil took of a 2x4 log lurched right though a car tyre and into the car chassis and an article in 'The Greymouth Evening Star', Friday March 11 2005
Coast tornado 'hot spot'
Metservice weather ambassador Bob MeDavitt says large damaging tornadoes such as the one experienced yesterday are a rare event for New Zealand.
The West Coast is regarded as one of country's 'hot spots', along with north Taranaki, Waikato, Auckland and the Bay of Plenty, but the scale of yesterday's destruction was unusual.
New Zealand tornadoes are small compared to those experienced in the United States, and this event appears to be one of the bigger ones, Mr McDavitt told the Evening Star.
"Normally you would expect a damage trail in New Zealand to be about a kilometre long and perhaps up to 100 metres wide.
"What happened yesterday appears to be one of the bigger ones.
"It's caused by a cold air collapse of the storm cell's top, much like it's been hit by a head-high tackle seen in rugby or league.
"The cell's strong winds aloft, then rapidly collapse to ground level, causing all the damage.
"On the recognised scale used to measure the damage of tornadoes - the Fujita Scale - this would probably be rated toward the top end of F1, perhaps just into F2. "
Mr McDavitt said the wind speed may have been of the order of 150-180 kilometres an hour. Severe wind shear is a damaging feature of such events.
Witnesses said the large swirling funnel of debris observed in yesterday's tornado reminded them of what is seen in TV footage of American events.
In June 2003, about 20 businesses were damaged when a tornado cut a swathe through downtown Greymouth and caused $300,000 worth of damage.
Another tornado that caused damage occurred in the early hours of March 28, 2001.
I am sending a photo that Neil took of a 2x4 log lurched right though a car tyre and into the car chassis and an article in 'The Greymouth Evening Star', Friday March 11 2005
Coast tornado 'hot spot'
Metservice weather ambassador Bob MeDavitt says large damaging tornadoes such as the one experienced yesterday are a rare event for New Zealand.
The West Coast is regarded as one of country's 'hot spots', along with north Taranaki, Waikato, Auckland and the Bay of Plenty, but the scale of yesterday's destruction was unusual.
New Zealand tornadoes are small compared to those experienced in the United States, and this event appears to be one of the bigger ones, Mr McDavitt told the Evening Star.
"Normally you would expect a damage trail in New Zealand to be about a kilometre long and perhaps up to 100 metres wide.
"What happened yesterday appears to be one of the bigger ones.
"It's caused by a cold air collapse of the storm cell's top, much like it's been hit by a head-high tackle seen in rugby or league.
"The cell's strong winds aloft, then rapidly collapse to ground level, causing all the damage.
"On the recognised scale used to measure the damage of tornadoes - the Fujita Scale - this would probably be rated toward the top end of F1, perhaps just into F2. "
Mr McDavitt said the wind speed may have been of the order of 150-180 kilometres an hour. Severe wind shear is a damaging feature of such events.
Witnesses said the large swirling funnel of debris observed in yesterday's tornado reminded them of what is seen in TV footage of American events.
In June 2003, about 20 businesses were damaged when a tornado cut a swathe through downtown Greymouth and caused $300,000 worth of damage.
Another tornado that caused damage occurred in the early hours of March 28, 2001.
