Tag Archives: Tornadoes

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Early warning for US states in Tornado Alley

Research showing that tornadoes are gradually forming earlier in the US could help states in the frontline to prepare better to withstand the storms’ devastating effects. LONDON, 21 September, 2014 − The terrifying whirlwinds that punctuate the mid-Western summer in the US so frequently as to earn the nickname “Tornado Alley” for the southern plains region states such as Nebraska, Kansas, Oklahoma and northern Texas are forming up to two weeks earlier than they did 60 years ago. John Long and Paul Stoy, research scientists at Montana State University, report in the journal Geophysical Research Letters that, on average, the tornado season advanced by one week between 1954 and 2009. For many states, the shift is almost 14 days. Peak activity on average used to occur on 26 May, but this century the peak has shifted to 19 May. On the plus side, the tornado season is also ending earlier than it did in the 1950s. Tornadoes happen in every continent except Antarctica, but particularly in America. There are on average around 1,300 in the US every year, and on average they kill about 60 people. They are graded according to the punch they pack: the Fujita scale of tornado rating ranges from F1, with winds at 117 kilometres per hour to 180 kph, to F5, at between 420 kph and 511 kph.

Increase in ferocity

Long and Stoy are not the first to note a change in the pattern of storms. Recently, researchers calculated that, overall, the number of tornadoes each year may be dwindling, but their ferocity seems to be on the increase. Some researchers think climate change is a factor, but the two Montana scientists are more cautious. They say it takes a mix of topography, temperature, wind patterns and other factors to set in motion the swarms of storms that can slam into a town and wreck tens of thousands of homes in a matter of minutes. “Observed climate trends cannot fully account for observations,” they say in the formal language demanded by science journals. But they also point out that if the tornado season is occurring earlier in the year, then it might help individuals, local authorities, emergency services and state governments to know this, and to be prepared. – Climate News Network

Research showing that tornadoes are gradually forming earlier in the US could help states in the frontline to prepare better to withstand the storms’ devastating effects. LONDON, 21 September, 2014 − The terrifying whirlwinds that punctuate the mid-Western summer in the US so frequently as to earn the nickname “Tornado Alley” for the southern plains region states such as Nebraska, Kansas, Oklahoma and northern Texas are forming up to two weeks earlier than they did 60 years ago. John Long and Paul Stoy, research scientists at Montana State University, report in the journal Geophysical Research Letters that, on average, the tornado season advanced by one week between 1954 and 2009. For many states, the shift is almost 14 days. Peak activity on average used to occur on 26 May, but this century the peak has shifted to 19 May. On the plus side, the tornado season is also ending earlier than it did in the 1950s. Tornadoes happen in every continent except Antarctica, but particularly in America. There are on average around 1,300 in the US every year, and on average they kill about 60 people. They are graded according to the punch they pack: the Fujita scale of tornado rating ranges from F1, with winds at 117 kilometres per hour to 180 kph, to F5, at between 420 kph and 511 kph.

Increase in ferocity

Long and Stoy are not the first to note a change in the pattern of storms. Recently, researchers calculated that, overall, the number of tornadoes each year may be dwindling, but their ferocity seems to be on the increase. Some researchers think climate change is a factor, but the two Montana scientists are more cautious. They say it takes a mix of topography, temperature, wind patterns and other factors to set in motion the swarms of storms that can slam into a town and wreck tens of thousands of homes in a matter of minutes. “Observed climate trends cannot fully account for observations,” they say in the formal language demanded by science journals. But they also point out that if the tornado season is occurring earlier in the year, then it might help individuals, local authorities, emergency services and state governments to know this, and to be prepared. – Climate News Network

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Intense Thunderstorms Likely To Batter A Warming World

EMBARGOED until 0730 GMT on Tuesday 4 June Forecasting is still difficult but it looks like the world will become a more stormy place in the years ahead LONDON, 3 June – More intense thunderstorms combined with damaging winds are expected to occur because of climate change, according to speakers at the seventh European Conference on Severe Storms being held in Helsinki, Finland. However because thunderstorms are small in size on the scale of existing climate models it is not possible to tell whether they will also lead to more tornadoes and larger size hail – two of the most damaging problems associated with severe storms. Delegates at the conference – organised by the Finnish Meteorological Institute and the European Severe Storms Laboratory – are being told that the theory behind  forecasts for thunderstorms becoming more severe is based on the observation that, in a warmer world, the surface temperature and moisture increases create conditions for thunderstorms becoming more intense – and more frequent. Tornadoes However climate change also decreases the temperature difference between the poles and the equator.  It is this temperature difference, when cold and warm air masses collide, which causes dangerous wind sheer, in turn producing the devastating tornadoes such as occurred last month in Oklahoma. Due to the limitations of global models, scientists have so far been unable to say whether the risk of tornadoes increases as a result of these twin effects. Harold Brook, a researcher into severe thunderstorms at the National Severe Storms Laboratory in the US, is optimistic. “According to latest research the intensity of tornadoes will not increase, therefore incidents like in Oklahoma are not expected to be more frequent than today” says Brook. “However, most of the research on severe thunderstorms and tornadoes in climate change has focused on the US and it is unclear how well the lessons learned there apply to the rest of the world.” While tornadoes are less of a problem outside the US, heavy hail frequently causes severe crop losses and property damage in Central and Eastern Europe, across Bangladesh, India and other large land masses.  Lightning and large hail also kills people caught out in storms. In some countries in Eastern Europe special planes are on standby each summer to seed the larger thunderclouds with chemicals to stop the build up of damaging hailstones which can severely damage crops and cause considerable economic loss. Early warnings like air raid sirens are sounded so people can take shelter to avoid injury from hailstones. Even in Finland where the Severe Storms conference is taking place lightning, strong wind gusts and hail from thunderstorms are the most damaging severe weather incidents. – Climate News Network

EMBARGOED until 0730 GMT on Tuesday 4 June Forecasting is still difficult but it looks like the world will become a more stormy place in the years ahead LONDON, 3 June – More intense thunderstorms combined with damaging winds are expected to occur because of climate change, according to speakers at the seventh European Conference on Severe Storms being held in Helsinki, Finland. However because thunderstorms are small in size on the scale of existing climate models it is not possible to tell whether they will also lead to more tornadoes and larger size hail – two of the most damaging problems associated with severe storms. Delegates at the conference – organised by the Finnish Meteorological Institute and the European Severe Storms Laboratory – are being told that the theory behind  forecasts for thunderstorms becoming more severe is based on the observation that, in a warmer world, the surface temperature and moisture increases create conditions for thunderstorms becoming more intense – and more frequent. Tornadoes However climate change also decreases the temperature difference between the poles and the equator.  It is this temperature difference, when cold and warm air masses collide, which causes dangerous wind sheer, in turn producing the devastating tornadoes such as occurred last month in Oklahoma. Due to the limitations of global models, scientists have so far been unable to say whether the risk of tornadoes increases as a result of these twin effects. Harold Brook, a researcher into severe thunderstorms at the National Severe Storms Laboratory in the US, is optimistic. “According to latest research the intensity of tornadoes will not increase, therefore incidents like in Oklahoma are not expected to be more frequent than today” says Brook. “However, most of the research on severe thunderstorms and tornadoes in climate change has focused on the US and it is unclear how well the lessons learned there apply to the rest of the world.” While tornadoes are less of a problem outside the US, heavy hail frequently causes severe crop losses and property damage in Central and Eastern Europe, across Bangladesh, India and other large land masses.  Lightning and large hail also kills people caught out in storms. In some countries in Eastern Europe special planes are on standby each summer to seed the larger thunderclouds with chemicals to stop the build up of damaging hailstones which can severely damage crops and cause considerable economic loss. Early warnings like air raid sirens are sounded so people can take shelter to avoid injury from hailstones. Even in Finland where the Severe Storms conference is taking place lightning, strong wind gusts and hail from thunderstorms are the most damaging severe weather incidents. – Climate News Network