Researchers say a mathematical tool they have developed can improve forecasting of extreme rains with a high degree of accuracy. ‘Using this kind of tool will likely save lives.’
By United with Israel staff
Hebrew University researchers say they have identified the factors affecting the likelihood of extreme rain events and have developed a tool that can improve the forecasting of such events, thus helping to prevent disasters. The tool is to be made available to the Israel Meteorological Service and its counterpart agencies throughout the world.
The new research study was led by Dr. Assaf Hochman and doctoral student Tair Plotnik at the Institute of Earth Sciences at the Hebrew University.
Extreme rain events, particularly those that cause flash floods in southern and eastern Israel in spring and fall (such as the floods in Nahal Tzafit in April 2018 that claimed the lives of 10 youths), are particularly difficult to forecast, even shortly in advance. Dr. Hochman and his team studied the factors that affect the ability to predict such extreme rain events, which are linked to a weather phenomenon known as an Active Red Sea Trough.
The research team – which also included Elizabeth-Ruth Shehter, Dr. Shira Raveh-Rubin, and Dr. Leehi Margaritz-Ronen of the Weizmann Institute of Science, and Dr. Francesco Marra of the University of Padova in Italy – used an extensive database belonging to the European Center for Medium-Range Weather Forecasts (ECMWF) to examine all extreme rain events that have occurred since 1979, and to sort them into “hard-to-forecast” and “easy-to-forecast” categories.
They found that one of the factors preventing optimal forecasting of extreme rain events is the simultaneous entry into Israel of air masses from both the north and south, due to the significantly different characteristics of each.
The researchers say that a mathematical tool they have developed can improve forecasting even in difficult cases, so that in the near future, it will be possible to predict the extremity of rain events with a high degree of accuracy. Such capability, they add, could allow decision-makers to prepare for such events so that human lives can be saved.
“The study, and the tool we subsequently developed, allow us to examine the factors that create extreme rain and thus to forecast the conditions in which extreme rain events will develop,” Dr. Hochman explained.
“Using this kind of tool will likely save lives, as in the future, it will allow the authorities to predict extreme rain events and to prepare for them properly. As we have seen, such events can cost human lives.”
“We plan to collaborate with the Israel Meteorological Service and other large forecasting institutions around the world, in order to operationalize our unique new approach,” he added.