Meteorology Department News
North Atlantic storm patterns throw light on 1987 gale
Release Date : 16 May 2012
The cyclone that brought about the devastating winds that battered the UK in the great storm of October 1987 was exceptional in both its strength and path across the south of the country.
This is the finding of a new study which has analysed the places where sting jets - an area that develops in some cyclones and causes strong surface winds - appear in the North Atlantic and how often they do so.
Presenting their results in the journal Environmental Research Letters, researchers from the University of Reading and Monash University, Australia, studied the hundred most intense storms to have occurred across the North Atlantic in the past twenty years.
Of the 100 storms studied, they found that around 30% of the storms had the potential to produce sting jets but these seemed to originate in relatively warmer, more southerly latitudes, out at sea.
A sting jet originates in a cyclone at an altitude of five kilometres within layers of moist ascending air. As the jet of air descends, it passes through clouds of ice crystals that cool it down, increasing its density and causing it to accelerate to speeds of up to 100 mph.
These strong winds appear in regions of a cyclone where they would not usually occur according to previous models.
"This descending jet is called a sting jet due to its location at the tip of the cloud head that wraps around the storm centre. This cloud resembles a scorpion's tail because of its hooked shape and is therefore described as the sting at the end of the scorpion's tail," said lead author of the study Dr Oscar Martínez-Alvarado, from Reading's Department of Meteorology.
The research shows that sting jets are a common feature of the most intense North Atlantic storms and that the potential impact of these storms crossing heavily populated areas should be considered by the insurance industry, policy makers and engineers who rely on these types of scientific advances to assess risk.
The time period analysed in this study was between 1989 and 2009. However, the researchers have highlighted two recent storms that struck Scotland in December last year and January this year, which both showed signs of a characteristic sting jet and produced winds of over 100 mph, leaving thousands of people without power.
"There is no evidence to suggest that sting jet storms are becoming more frequent. It really remains a question of chance," said Dr Martínez-Alvarado.
"Using a technique similar to the one we used here, it would be possible to see signs of the potential for sting jets some six hours in advance. However, their time and length scales are so small that forecasting their actual occurrence remains a very difficult task."
Be part of science history by joining the Forecast Factory
Release Date : 08 May 2012
Science enthusiasts will be able to see how weather forecasts work while helping to create the world's largest weather-predicting human computer at Reading Town Hall next month.
The Forecast Factory experiment, organised by meteorologists at the University of Reading, will attempt to recreate an idea first put forward by weather pioneer Lewis Fry Richardson 90 years ago, but which has never been attempted at such a large scale - until now.
Organisers are now seeking 200 enthusiastic people, aged eight plus, to arm themselves with a pencil, paper and calculator and become a vital cog in the world's largest ever human computer designed to predict the weather.
The free event, in the Town Hall on Sunday 3 June, is part of the Reading WAM Festival (Weather, Art and Music) over the Jubilee Bank Holiday weekend.
Participants will also have a chance to meet Met Office forecaster Laura Tobin, who is a BBC weather forecaster and a former University of Reading student, and scientists from the world-leading Department of Meteorology at the University of Reading and the Reading-based European Centre for Medium-Range Weather Forecasts.
Andrew Charlton-Perez, a meteorologist from the University of Reading, said: "This is a fascinating and ambitious attempt to carry out an experiment that was first put forward by one of the fathers of modern weather forecasting.
"You will need no previous experience of meteorology, maths or science to take part. But you will form part of a human computer that will work in exactly the same way as the modern supercomputers used to predict the weather by scientists today.
"This is a unique experiment and it promises to be a lot of fun. We look forward to seeing you."
Fry Richardson first put forward his idea for weather forecasting - in which a series of calculations are made across a grid, with the results for each grid cell depending on the output of those around it - in 1922, and he proposed that a large group of people could be used to make the calculations quickly and accurately.
However, his idea for what he called a 'forecast factory' to make the calculations was overtaken by electronic calculating machines in the 1950s - the forerunners of modern computers - and was therefore never tested.
The event will take place in two sessions, from 10am-12pm and 2-4pm on Sunday 3 June. Tickets are free, but limited to 200 people. Visit the Town Hall box office website or call the box office on 0118 960 6060 for tickets.
East Berks experiences twice the normal amount of April rain
Release Date : 01 May 2012
Reading and Maidenhead experienced over twice the normal amount of rainfall for April according to weather scientists at the University of Reading.
With water companies having enforced a hosepipe ban across the south of England from 5 April, researchers at the University of Reading recently calculated that the region needs twice as much rainfall over the summer than normal to get back to expected levels.
In April, the University received 120 mm while 114 mm fell in Maidenhead. These areas would normally expect to experience 48 mm. However, neither of these totals quite reached the record falls set in April 2000 (121 mm in Maidenhead and 133 mm at the University), which in turn was the wettest April locally in the past 60 years.
Dr Roger Brugge, from the University of Reading's renowned Department of Meteorology, said: "Following a remarkably warm and dry March in East Berkshire April 2012 has brought a return to cooler and wetter conditions. All this rain has come from frontal systems brought to us by areas of low pressure that have been persistently close to, or over the British Isles for most of the month. One wet month is not enough to replenish water sources underground though. Much of the early rain will have created runoff into rivers due to the hard ground surface and the deficit over the past year alone has been less than the surplus this month.
"April 2012 has been colder overall than March 2012 by about 0.8 degC. However, such a reversal in temperature between these two months is not as unusual as you might think. At the University in 1989 March was remarkably 1.2 degC warmer than April.
"With the rain has come cloud and a lack of any hot days. The highest temperature in April before the 30th was just 15.1C recorded on the 8th. Maidenhead recorded 16.3C on the 22nd. However, it turned slightly warmer on the 30th with 19.7C being recorded in Maidenhead and 18.9C at the University.
"However, both these temperatures were well below the March highs this year of 21.4C at the University and 22.7C in Maidenhead."
Why Europe's climate faces a stormy future
Release Date : 02 April 2012
Europe is likely to be hit by more violent winter storms in the future. Now a new study into the effects of climate change has found out why.
A weakening of the warm North Atlantic ocean current, the Meridional Overturning Circulation, during the next century has already been predicted by climate scientists, with suggestions it could lead to colder sea temperatures and reduced warming in Britain.
But new research by scientists at the University of Reading's Walker Institute and the University of Cologne suggests that the weakening of the warm current could also partially shut down Europe's protection against violent storms blowing in from the ocean.
The research, published on April 1 in the journal Nature Geoscience, suggests that without such strong warm ocean currents, the regional temperature variations in the North Atlantic will increase.
Such temperature variations, or gradients, help to power storms as they brew up over the ocean. The increase in regional gradients in the Atlantic suggests that the number of storms following a more southerly track, therefore hitting land in Europe, will also increase as greenhouse gas levels rise in the atmosphere.
This is contrary to predictions about changes to storm tracks in other parts of the globe, where increasing temperatures are expected to cause storms to reach higher latitudes than is currently the norm.
The findings are likely to be useful for planners, policy makers and businesses that will need to prepare for the impending changes to our climate in the years ahead.
Dr Tim Woollings, from the University of Reading's Department of Meteorology, said: "From the climate models studied, we expect more storms will hit Europe as the 21st century progresses. We found that changes in ocean currents, in response to increasing levels of greenhouse gases, are crucial in shaping the North Atlantic storm track changes.
"Predictions showed obvious changes to expected weather patterns by the end of the century, but it is not yet clear exactly when this signal may first emerge.
"Predicting future changes to storm patterns can be difficult, and we have shown that in order to improve confidence in these predictions we need to improve our observations and models of ocean currents."
The researchers studied and compared a number of climate models, including those used to help compile the influential fourth assessment report of the Intergovernmental Panel on Climate Change.
Professor Ted Shepherd appointed to Grantham Chair in Climate Science
Release Date : 02 April 2012
The University of Reading is delighted to announce the appointment of Professor Ted Shepherd to the Grantham Chair in Climate Science. Professor Shepherd will play a leading role in climate research in the University of Reading's Department of Meteorology, the renowned international centre for the study of weather and climate, and in the University's Walker Institute for Climate System Research.
Professor Shepherd, currently based at the University of Toronto, is acknowledged to be one of the leading atmospheric scientists of his generation. His outstanding research record over the past 30 years encompasses atmospheric dynamics, climate dynamics and climate change, and he is particularly known for his research on the stratosphere, the atmosphere above 10 km.
Professor George Marston, Dean of the Faculty of Science at the University of Reading, said: "We are delighted that we have recruited a scientist of Ted Shepherd's calibre to the Grantham Chair in Climate Science. We are already one of the leading international centres for weather and climate research. Professor Shepherd will provide a further boost for our research excellence, and new leadership in climate science at Reading and for the UK."
This appointment is one part of a large current investment in weather, climate and related areas of environmental science at Reading by external funders and the University. In particular, building on this recent funding by the Grantham Foundation and other funding by the UK Met Office and Willis Re, the University is investing in the creation of over 15 new academic posts over the next six months in Climate and Environmental Sciences in the Department of Meteorology and more broadly across the University, with the aim that Reading become the number one academic centre internationally for weather and climate research.
Professor Shepherd takes up his post at the University of Reading on 1 May 2012.
