A powerful blocking anticyclone will dominate the weather over Europe until the end of June, and likely into early July. Models show that geopotential heights at the 500 mbar level will reach record values, which is indicative of an extremely powerful and unusual “heat dome” for this time of year.
The compression of air within this dome causes not only an increase in temperatures, but also an increase in atmospheric pressure near the earth’s surface. Since no significant atmospheric disturbances are expected, the heat wave will be long-lasting. The high pressure area will gradually expand from the southwest towards the central and northern parts of the continent.
Temperature anomalies, i.e. deviations from the average, are already extreme and reach 15 to 20 degrees Celsius above the usual values for the end of June.
After the heat wave has already affected France, Spain and Portugal, during the week it will expand towards the Benelux countries and the United Kingdom, while during the weekend it will also include Germany, Scandinavia, Poland and finally the Alpine area and the Balkans. /Telegraph