La Niña also influences our winter and will bring heavy rains to Italy

Abundant rainfall in the western Mediterranean, cold temperatures above average in France, Germany and England. In addition, for the third consecutive year, La Niña is expected to bring cold and dry conditions to the southeastern Pacific regions and increased rainfall to Central and South America. This is the possible meteorological picture obtained from international research groups through the analysis of forecasting models.

A team from the Institute of Atmospheric Physics in China has also looked into how La Niña might combine with the effects of global warming. The survey, published in the magazine Advances in Atmospheric Science, points out that these are very complex processes to study, with an outcome that is sometimes unpredictable. Despite La Niña, however, from the data it seems that a good part of Europe could experience temperatures higher than the average expected for the period.

La Niña, a more frequent anomaly

La Niña is a complex meteorological phenomenon, in fact an anomaly, which occurs on average every 5 years. This involves an anomalous cooling of the tropical Pacific Ocean in the central-eastern region – off the coasts of South America – accompanied by drought, while it contributes instead to an increase in rainfall in the more distant western regions, on the eastern Asian oceanic coasts and in Oceania. La Niña is the ‘counterpart’ of El Niñoalso regular and recurring, which instead causes anomalous heating of the waters of the eastern tropical Pacific and heavy rainfall in large areas of South America and the south-western part of the United States.

By juxtaposing the averages, which see La Niña appearing on average every 4-5 years, for the third consecutive year this anomaly should also manifest itself with a tangible impact in 2023. “La Niña has effects on a global scale“, points out Silvio GualdiDirector of the Climate Simulation and Forecasting Division of Euro-Mediterranean Center on Climate Change (CMCC)“although at the European level it is difficult to identify and quantify them, while they are more measurable in North and South America, in Africa in Oceania and in East Asia”.

I study

Researchers from the Institute of Atmospheric Physics in China examined four forecast models and their analysis concerned Eurasia, a geographical name by which the continental area that includes Europe and Asia is identified. The team observed overall warming, partly in contrast to the presence of La Niña, which usually causes cold winters in Eurasia. To interpret the data, the authors point out that the results could in part be influenced by climate change, in particular by global warming, or by bias (‘systematic errors’) in the examined models. Furthermore, subsequent elaborations, starting from the results obtained, indicate that it is still possible that in winter 2023 there will be below average temperatures in Eurasia, in particular in the middle latitudes.

“The work in question is of interest”, comments Gualdi, not involved in the study, “given that, as usual, it seeks to understand through climate models how the weather scenario will evolve next season. The research is limited to some models and it is not the only one of this kind within the sector”. In general, in fact, there are some international groups (and the CMCC is one of these) which are Global producing centers of seasonal forecasts – obviously we never talk about certainty but we always fall within the concept of probability Among the programs that deal with these forecasts, there are those supported by Copernicus and that of the World Meteorological Organization (WMO).

Winter 2023 in Europe

Precisely these Centers and these programs have provided estimates for the next cold season. “According to the data just discussed”, explains Gualdi, “in central-western Europe – in particular in an area that includes France, Germany, the United Kingdom and Ireland and the British Isles – temperatures are forecast to be colder than the seasonal averages of recent years “. The phenomenon will mainly concern the beginning of winter, between December and January. “In the western part of the Mediterranean basin (including Italy, ed) significant temperature anomalies are not expected”, adds the expert, “while an increase in seasonal rainfall is possible”