Heatwave: an ‘Omega’ weather pattern looms over Italy – what is it?
From Monday 13 July, temperatures are set to rise further, with highs of over 40 degrees in Sardinia. According to the Lamma Consortium, the rise is due to the “Omega pattern”
The third heatwave of the year is continuing and, according to meteorologists’ forecasts, is set to last at least until 20 July. Following a weekend of unsettled weather characterised by a few intense thunderstorms in northern Italia, temperatures are set to rise, reaching peaks of 43 degrees in Sardinia, where temperatures in Oristano are already expected to reach 39 degrees over the weekend. The sharp rise forecast from Monday, according to the Lamma Consortium of the National Research Council (CNR) and the Region of Tuscany, is attributable to the ‘Omega configuration’.
The “Omega configuration”
The Lamma Consortium explains that, from the start of next week, a low-pressure system to the west of the Iberian Peninsula will draw in warm air of desert origin, which will strengthen the high-pressure system that has already been over our country for weeks. At the same time, another low-pressure system will develop between Eastern Europe and the Black Sea, giving rise to the ‘Omega pattern’. As a result, the centre of the high-pressure system will shift further east, affecting the whole of Italia, including the southern regions, which have so far been less affected by the heat.
The Consortium adds that ‘a high-pressure system acts like a huge dome that traps warm air. This air sinks towards the ground, where it is compressed and heats up even further. At the same time, the high pressure prevents clouds from forming and blocks the arrival of cooler air currents, such as those from the Atlantic. The result: clear skies and steadily rising temperatures’.
According to Lamma, the “Omega pattern” is not in itself an exceptional phenomenon, although “climate change is strengthening its anticyclonic component: the high-pressure ridge is shifting further and further north, bringing the heat as far as northern France, England and even Scandinavia”.
Rising temperatures
As of today, the most critical situations in the country are in Florence and Perugia, which will remain on ‘red alert’ – the highest alert level – until Sunday. “The heat,” says Lorenzo Tedici of iLMeteo.it, “is set to intensify, particularly from Sunday onwards.”
