Another heat wave is currently developing over Western Europe and the media are pointing the finger at climate change but more likely is a result of a growing area of negative sea surface temperature (SST) anomaly that has developed over the eastern North Atlantic that is enhancing undulations in the jet stream.
Currently below normal SST anomalies have developed over the eastern North Atlantic with the greatest negative anomaly between the Azores and the coast of Portugal while positive anomalies remain over the western Mediterranean, Bay of Biscay, English Channel and Baltic Sea.
These conditions tend to favor upper-level troughs to develop over the eastern North Atlantic with ridging building over western Europe, and in fact is the current situation. As the upper-level ridge builds over western Europe, the air temperatures at the surface increase accordingly. Over several days the ridge will drift eastward spreading the heat into central Europe.
Whether or not the SST anomalies are associated with climate change is open to debate.
Ref: Impact of North Atlantic SST and Jet Stream anomalies on European Heat Waves, Julian Krüger et al.