The name comes from the Greek letter omega, which has the same shape - a rising “bubble” of intense heat, surrounded by cooler air that makes it difficult for the bubble to move.
It draws up hot air from the Sahara, with intense heat that moves very slowly - no wind, no respite, says expert Clair Barnes, an extreme weather researcher at Imperial College in London, to the Reuters news agency.
“Warmer and warmer”
In this case, the “bubble” of air from Africa is centered around northern France. This could lead to record heat in several capitals; for example, almost 40 degrees in Berlin and well over 40 in Paris. New records are expected primarily on Wednesday and Thursday. Magnus Joelsson tells TT that the omega blockade began about a week ago, and that the heat has built up since then.
When it stays in the same place, it gets warmer and warmer over time.
Omega blockages are neither new nor unusual. But human use of fossil fuels makes them worse. Clair Barnes estimates that a summer heatwave like this will mean temperatures “two to four degrees higher than they would have been without the warming we humans are causing.”
Once these occur, it means it will be warmer than it would have been in a pre-industrial climate, says Magnus Joelsson.
40 degrees in London?
For example, the UK's June temperature record is 35.6 degrees. But this week there are fears that the 40 mark could be crossed in the London area. At the same time, London Climate Action Week, an international conference for action against climate change, is being held. The coincidence prompted UN chief António Guterres to exclaim in his opening speech on Tuesday:
London is not just calling - it is boiling!
By the weekend, however, the "bubble" will have burst, and the Sahara air will also reach Sweden and the Nordic countries, but in a diluted form.
Yes, exactly. So it probably won't be 40 degrees for us. But it will be hot anyway,
Magnus Joelsson tells TT.
