Temperatures under normal: the reasons for the cost in France

An Atlantic backbone responsible for refreshment

This week. Similarly, Western Europe is under the influence of a fresh and humid northwest flow. Moreover, This configuration results from the implementation of an Atlantic dorsal diet (or Atlantic Ridge, “AR” in English). Furthermore, Concretely. However. Meanwhile, a powerful anticyclone extends from the Azores to Iceland, inducing a drier and more stable air thrust on the North Atlantic.

Géopotentiels 500 HPA © LCM

At the same time. However. In addition, a depression centered in Scandinavia pilot a flow from north to north-west on France, the United Kingdom, Benelux and part of Germany. Additionally, However, This polar sea air leads to a significant drop in temperatures. sometimes 4 to 6 ° C temperatures under normal: reasons cost new below seasonal averages in the north and west of France. This temperatures under normal: reasons cost type of situation is rather rare in the heart of summer, but not exceptional.

The key role of undulations of jet stream

At the origin of this atypical configuration. there is a key player in atmospheric circulation: the Jet Sstream. This current of altitude, blowing between 9,000 and 12,000 meters, acts as a rail guiding depression and anticyclonic systems.

Currently. this jet presents a strong undulation: it deeply plunges towards the southwest of Europe. promoting the descent of fresh air on the Atlantic facade, then goes up brutally to southeast Europe. Furthermore, This wave movement – which can be compared to a winding snake – creates a real set of communicating. vases in the atmosphere.

Jet Stream © LCM temperatures under normal: reasons cost new

Intense heat wave on southeast Europe

Mirroring this freshness in the west. southeast Europe temperatures under normal: reasons cost is a remarkable heat wave. The hot air. of Saharan origin, is sucked in by the return of the jet to the Balkans, Romania, Bulgaria or even Greece. Temperatures reach 40 to 45 ° C there, especially in major Greek cities like Athens, Patras or Larissa.

This situation illustrates well the direct impact of the meanders of the Jet STream on the distribution of air. masses across the continent. While the French sometimes stand out the sweaters, the Greeks face extreme temperatures and tropical nights.

Folie air masses © LCM

Atmospheric mechanics well known to meteorologists

These Atlantic dorsals are not new. they testify to an increasingly undulatory atmosphere, where thermal contrasts temperatures under normal: reasons cost new can be very strong over short geographic distances.

Note that these diets also promote drier periods on the Atlantic facade. despite temperatures under normal: reasons cost the current freshness. This situation could move fairly quickly with the return of summer conditions by the weekend on almost all of France.