New tool can predict extreme weather events

Extreme climate events such as heatwaves, floods, or droughts often occur with little or no warning, making effective short-term response to them almost impossible. A research team led by the Potsdam Institute for Climate Impact Research (PIK) has recently developed a new network-based framework which allows more accurate predictions of weather events.

“Currently, for instance, there is no reliable prediction of heavy rainfall in the Easter Central Andes leading to floods and landslides with devastating impacts for the inhabitants in that part of South America,” said study co-author Jürgen Kurths, a climate expert at PIK. “Our network-based approach can predict those events up to two days in advance – that is crucial time for the people to prepare, save lives and limit damages.”

Traditional weather and climate forecasting rely on numerical methods imitating atmospheric and oceanic processes, and can’t always accurately and timely predict phenomena such as monsoon offsets, floods, or droughts. By contrast, the new network-based forecasting, which instead of simulating the entire Earth system, analyses large-scale connectivity patterns in observational data, is much more efficient in predicting the onset of extreme weather events.

“As opposed to looking at a huge number of local interactions, which represent physical processes like heat or humidity exchange, we look directly at the connectivity between different geographical locations, which can span continents or oceans,” explained study lead author Josef Ludescher, a senior scientist at PIK. “This connectivity is detected by measuring the similarity in the evolution of physical quantities like air temperatures at these locations. For instance, in the case of El Niño, a strong connectivity in the tropical Pacific tends to build up in the calendar year before the onset of the event.”

“The new forecasting approach has, in several instances over the past years, proven to be highly efficient in predicting different climate phenomena much earlier than before. El Niño for instance could be predicted up to one full year early, compared to about six months with the standard prediction methods. The onset of the Indian Summer Monsoon in central India, vital for the economy in this region, was predicted more than a month in advance, much earlier than the forecast currently used, thanks to the new approach,” he added.

This new weather prediction tool, which could potentially save millions of lives and help avoiding billions of economic costs, is described in the journal Proceedings of the National Academy of Sciences.

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By Andrei Ionescu, Earth.com Staff Writer