The meteorological situation in October 2019 was characterised by a lower than normal monthly mean surface pressure in most parts of the EFAS domain reflecting the recurring occurrence of low-pressure systems, whereas it was higher than normal in the northwest of the EFAS domain. Monthly precipitation totals were below normal in the southwest and southeast of the EFAS domain as well as in the north. The monthly mean air temperatures were above normal in most parts of the EFAS domain.

Floods in Great Britain in the first days of October were caused by heavy precipitation that fell mainly in the last days of September. At the beginning of October, a low-pressure system formed over Scandinavia and a secondary low-pressure system was situated over western Great Britain and Ireland, while the Mediterranean region was influenced by a high-pressure system. As the secondary low-pressure system moved to the eastern Alps, it initiated a flow of cold air at the upper levels, which initiated heavy precipitation events mainly over the Balkans. Precipitation amounts to above 70 mm in twelve hours were reported. Simultaneously, hurricane Lorenzo, which developed in the last decade of September, moved across the Azores and British-Irish Isles to central Europe and disappeared. On its way it caused destruction in the Azores (mainly due to strong wind) and floods in Ireland. Later, a low-pressure system developed over western Russia and moved northward to the Arctic.

Yet another low-pressure system developed next to Newfoundland and moved fast over the Atlantic Ocean. It slowed down between Iceland and British-Irish Isles and later became stationary over the Norwegian Sea. At the same time, a low-pressure system developed below an upper level trough over western Russia. Both troughs merged, and the later low-pressure system moved via eastern Scandinavia to the Arctic. By mid-October, a low-pressure system developed between Greenland and Iceland and moved in a long bow over the Atlantic to the British-Irish Isles. The corresponding trough extended southward to the Iberian Peninsula including cold air at the upper levels. This initiated the development of an upper-level low-pressure system, which moved around the Iberian Peninsula and later to the central Mediterranean region. It caused high precipitation amounts especially in southern France and northern Italy with more than 70 mm in three hours, but also at the southern coast of the Mediterranean Sea. During the same days, a low-pressure system moved from Newfoundland to the Norwegian Sea and brought large-scale precipitation to Great Britain, causing again floods by the end of the month. In the last days of October, a high-pressure system developed over the Atlantic Ocean and moved to eastern and central Europe. Together with the eastward shifted Azores high it caused steady weather conditions to nearly the whole EFAS domain, while weak low-pressure systems occurred over northern Scandinavia and Russia.

In October 2019, the highest precipitation totals were observed in the southern parts of France Italy, but also in other coastal regions at the Atlantic Ocean, North Sea, Mediterranean Sea and Black Sea as well as in Russia (Figure 1). No or nearly no precipitation fell in parts of northwest Africa and south of the Caucasus Mountains. More than normal precipitation was observed in central and western Europe, southern Scandinavia and large parts of Russia (Figure 2). Less than normal precipitation fell in the southwest and southeast of the EAFS domain as well as in the northern parts.

The monthly mean air temperature ranged from -8.9°C to 32.4°C with the highest values in the southern parts and lowest in the northern and mountainous parts of the EFAS domain (Figure 3). Air temperature anomalies ranged from -5.8°C to 8.6°C (Figure 4). Monthly mean temperature values were above the long-term mean over almost the whole EFAS domain except for Scandinavia and northwest Russia, Great Britain and Ireland, Iceland, Portugal and some regions in northwest Africa.