Tagged: tornados

Tornado strength, frequency, linked to climate change

New research by a Florida State University geography professor shows that climate change may be playing a key role in the strength and frequency of tornadoes hitting the United States.

…Professor James Elsner writes that though tornadoes are forming fewer days per year, they are forming at a greater density and strength than ever before. So, for example, instead of one or two forming on a given day in an area, there might be three or four occurring…

Elsner, an expert in climate and weather trends, said in the past, many researchers dismissed the impact of climate change on tornadoes because there was no distinct pattern in the number of tornado days per year. In 1971, there were 187 tornado days, but in 2013 there were only 79 days with tornadoes.

But a deeper dive into the data showed more severity in the types of storms and that more were happening on a given day than in previous years…

The United States experiences more tornadoes than any other country, and despite advances in technology and warning systems, they still remain a hazard to residents in storm-prone areas. The 2011 tornado season, for example, had nearly 1,700 storms and killed more than 550 people…

One bright spot of news in the research, Elsner added, was that the geographic areas impacted most regularly by tornadoes do not appear to be growing.

Interesting work and especially relevant in this period of climate change. Too bad politicians and other scatterbrains find it easier to focus on ideology and elections than actually developing a response to the changes we’re still analyzing and understanding.

Kudos to people like Professor Elsner for maintaining dedication to research even when there are know-nothings in the Florida legislature who would rather defund work like this than confront change.

Thanks, Mike

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In tornado alley, building practices boost damage toll


Damaged – and repairable

In a residential neighborhood near the center of a monster tornado that struck Moore, Oklahoma last month, two partially damaged houses stand like an island among others flattened by the storm.

The walls and roofs of the buildings in a new housing development called Featherstone Addition are still upright while there is nothing left but a concrete foundation where other homes once stood nearby.

The two homes were not completely spared but are salvageable, according to David Prevatt, a civil engineer who saw them when he surveyed the damage after Moore took a direct hit from an EF5 tornado, the strongest rating.

He is convinced that the two houses survived because they were built stronger than most in Oklahoma and the rest of “tornado alley” – the region stretching from Texas to Iowa that accounts for roughly a fourth of all U.S. tornadoes.

“This notion that we cannot engineer buildings economically to withstand tornado loads is a fallacy,” said Prevatt, who has studied damage from hurricanes and the devastating tornadoes in 2011 in Joplin, Missouri and Tuscaloosa, Alabama…

Damage costs are rising because of increased population density, even in mostly rural states such as Oklahoma, which has seen substantial urban sprawl in the last decade, said Greg Carbin, Warning Coordination Meteorologist for the National Weather Service’s Storm Prediction Center in Norman, Oklahoma.

Another important reason that has received less attention, is that most homes in tornado alley are not built to withstand even a modest tornado.

The result is that residents of tornado alley, insurance companies and the U.S. government are footing a mounting bill from damage that could be limited with better construction, according to several engineers, meteorologists and consumer advocates interviewed by Reuters.

“We have to stop this cycle of a storm coming along destroying things and we build them back the same,” said Leslie Chapman-Henderson, chief executive of the Federal Alliance for Safe Homes, a consumer group. “That is the official definition of insanity.”

Oklahoma should follow the example of Florida after Hurricane Andrew in 1992 and adopt a tougher building code to reduce damage in future, said Prevatt, Assistant Professor of Civil and Coastal Engineering at the University of Florida.

RTFA for a boatload of detailed information and analysis. Useful stuff – in a society that responds to thoughtful, scientific study. Unfortunately, that definition doesn’t especially include the United States.

International building codes, the standards for safety and sustenance, generally are about a decade ahead of the United States. Any progressive moves on the world stage take at least that long before consideration gets on the US agenda – Congress and the corporations supplying building materials to American homebuilders. The National Association of Home Builders starts work on analysis and understanding immediately if not sooner – but, everyone in the NAHB knows that the adoption process will be slower than the average tortoise.

Now, we could make regional changes based on what Florida and the hurricane states have learned. That’s still too easy for the States’ Rights crowd. You have to understand that a minor percentage of residents in Tornado Alley – and especially their favorite conservative politicians – still hate the idea of building standards, code ordinances and zoning.

Unprecedented international tornado study begins

An international team of researchers are embarking on what has been described as the most ambitious tornado study in history.

An array of instruments will be deployed across the US Great Plains, where violent twisters are more common than anywhere else on the planet. It is hoped that the data gathered will improve tornado warnings and forecasts.

More than 100 scientists will be involved in the study, which will continue until the middle of June…

The study, Vortex2, will use a range of enhanced mobile radars and other weather-sensing equipment in order to build up a comprehensive picture of the zones where tornadoes develop.

Researchers say that rapidly changing contrasts in wind and temperatures in an area just a few miles across can spawn a tornado in a matter of minutes.

But, they added, only a small percentage of “supercell storms” generate twisters, and standard observing networks and radars struggle to pick up the atmospheric conditions that lead to the formation of a tornado…

The study area stretches from West Texas to south-west Minnesota, covering more than 900 miles.

The researchers will not have a fixed base, spending the entire six weeks on the road following outbreaks of severe weather.

Surrounded by pilots in this family, you know I had to get this post up for the weekend.

Though, frankly, as someone who used to live on the road – in later years in regions including part of Tornado Alley – I’m as interested as any of the usual weather geeks in the family.