Abnormal heat and floods, the 'Omega blockade' is to blame

In Italy peaks of 33-35°C in the next few days

ROME - Abnormal heat across half of Europe, floods in Spain and Greece, fault of 'Omega block'. “The Omega Block is characterized by two low pressure circulations on the sides of a robust anticyclone– explains the meteorologist of 3bmeteo.com, Francesco Nucera-.In these circumstances the atmospheric waves, which are the basis of disturbances and anticyclones, do not evolve from west to east as they normally should do, but remain blocked for several days.The name of this type of atmospheric block derives from the letter of the Greek alphabet Omega which has a shape similar to the design generated by the carrying currents at altitude".

These persistence regimes, explains Nucera, “can last for a longer time with important meteorological consequences in the depressions and in the promontory.In fact, in the former, where low pressure centers are present, greater thermal contrasts will be generated with clouds and even intense and persistent precipitation.On the other hand, in the promontory there will be sunny and stable weather conditions with rising temperatures (very hot in summer) and long dry periods in the winter with an absence of rain and snow".

This is exactly what is happening these days in Europe - continues Edoardo Ferrara of 3bmeteo.com - with the African anticyclonic promontory stretching from Algeria towards England, Holland, Germany, eastern Spain and above all France, where we find decidedly anomalous heat for the period with temperatures above average even by 12-15 degrees:in London they came close to 31, Paris 32 and in France several September records also fell with peaks of 36-37 degrees. On the contrary on the sides of the anticyclone we witnessed the persistence of two cyclonic vortices:one between western Spain and Portugal with violent storms and local flash floods, the other still active hit Greece hard with historic floods and several victims.

Abnormal heat also in Italy, but signs of change from mid-month.“A good part of Italy is also affected by the African anticyclonic dome and in particular the Centre-North, where until the middle of next week decidedly high temperatures are expected for the period with peaks of up to 33-35 degrees by Monday.Heat is also intensifying in the South, which until now was actually affected, albeit marginally, by the Mediterranean cyclone with rain, thunderstorms and even strong winds. From 12-13 September the anticyclone could be at least partially dismantled by an Atlantic disturbance, responsible for showers and thunderstorms especially in the North, together with a drop in temperatures. An evolution which, however, will require further analysis and confirmation given the temporal distance", conclude from 3bmeteo.com.