Meteorologists to make major push for more accurate, long-term and useful weather forecasts over the coming decade

Scientific advances on climate change have been grabbing the headlines this year. Meanwhile, a quiet revolution has been underway in the tightly linked field of meteorology.

Eager to move weather forecasting skill rapidly forward over the next few years, some 1 000 scientists and experts are meeting in Montreal from 16 to 21 August for the first World Weather Open Science Conference to chart the future course of scientific research and its potential for generating new and improved weather services.

"Thanks to major investments in research and observations, today’s five-day forecast is as reliable as the two-day forecast of 20 years ago,” said Michel Jarraud, Secretary-General of the World Meteorological Organization.

"Now meteorologists and climate scientists are developing ‘seamless weather and climate forecasts’ that further blur the boundaries between weather and climate science. Continued scientific progress will make weather information and forecasts increasingly powerful tools for reducing risks from extreme events and managing the transport, energy, water and other vital systems that we all depend on,” said Mr Jarraud.

Until recently, weather forecasting and climate prediction were treated as separate scientific disciplines, in part because they faced different scientific challenges, but also because weather forecasting was always been designed as an operational service, whereas climate prediction is only now leading to services.

The science has progressed, assisted by advances in computing power, so that today, conceptually, the traditional boundaries between weather and climate are increasingly viewed as artificial. The weather and climate communities are working together to extend the reliability and usefulness of their forecasts to levels beyond what has previously been thought possible.

One of the issues to be explored in Montreal is how to build on recent research into the extension of forecasts of tropical cyclones and other high-impact weather events out beyond two weeks, while at the same time improving the site-specific accuracy of very short-range forecasts.

For example, Numerical Weather Prediction centres around the world have been developing “ensemble forecasts” consisting of as many as 50 or more simulations of events such as a storm’s potential path. Based on these predictions, probabilities can be assigned to the various possible tracks a storm might follow as well as to its future intensity. In the case of Hurricane Sandy, which devastated parts of the Caribbean and the eastern United States in 2012, this approach succeeded in providing early predictions of the storm’s highly untypical path.

Another promising area of research draws on improved observations and computing power to detect and understand broader patterns and cycles in the weather and climate system. A better understanding of how the oceans and atmosphere interact has led to a better understanding of observable sub-seasonal and seasonal patterns, particularly in the tropics.

The best known and most important of these is the El Niño/Southern Oscillation (ENSO), but other large-scale patterns of pressure also affect the weather and climate, and thus help to inform weather forecasts. Research and development of advanced models integrating both atmospheric and ocean dynamics now successfully capture more of these phenomena than ever before. This holds out the promise of exciting advances in the predictive skill and usefulness of weather forecasts and climate predictions over the next decade.

For example, the North Atlantic Oscillation is an east-west fluctuation of pressure between the high-pressure system centered over the middle of the Atlantic and the low-pressure system centered near the Arctic. It influences the strength and direction of westerly winds and storm tracks across the North Atlantic. As understanding of this oscillation continues to improve, so will weather prediction for Europe as well as Northern Africa and eastern North America.

Probabilistic forecasts, such as “there is a 90 per cent chance of a hail storm between 9 a.m. and noon,” will become increasingly accurate and geographically precise. Eventually, instead of running a model several times a day, forecasters may use continuously updated Earth prediction systems to produce real-time updates.

Benefiting from improved observations and growing computer processing power, modern weather science is rapidly leading to better forecasts of storms, heatwaves and other high-impact weather events. These advances will inform discussions at the 3rd World Conference on Disaster Risk Reduction being held in March 2015 in Sendai, Japan.

Looking further ahead, over the next 20 years forecasters are likely to move towards Earth system modelling, so that today’s seamless weather forecasts and climate predictions could evolve towards seamless weather-climate-impacts forecasting. Highly sophisticated models will incorporate more and more of the Earth system's components and processes. In addition to the atmosphere and oceans, they will integrate increasingly accurate information on topography, land-use change, vegetation, rivers, lakes, clouds and socio-economic trends to provide user-specific decision-support services that will touch almost every part of our lives.

These ongoing advances in weather and climate research will have many practical benefits for people. Customized forecasting products that integrate Earth science data with socio-economic data could be used to better manage complex evacuation procedures in the face of major storms or floods. They could also guide the managers of weather-sensitive systems such as water supply, sewage, energy and land, sea and air transportation responsible for ensuring safe and efficient operations. Current research priorities include increasing aviation safety and efficiency by upgrading “nowcasts” (up to two hours) and “very short range” (up to 12 hours) forecasts and supporting hydroelectricity and flood management through improved representation of the water cycle in weather models.

As Earth system prediction and communications technologies progress – including sensors and analytical tools that are wireless, mobile, high-powered and integrated – it is likely that enhanced forecasting skills will radically change how people live. Individuals may use forecasts to improve their quality of life and schedule their activities over the course of a day, week, month, season, or longer. They will use forecasts to better allocate resources to, for example, household energy supplies, and they will be able to confidently decide well in advance when to schedule weather-dependent travel, work, and sport.

Weather and climate have a huge impact on everyday living. The increasingly advanced forecasts and their future potential applications on the agenda at the World Weather Open Science Conference will empower people as never before in history
Source: www.wmo.int