The meteorological situation in September 2019 was characterised by an intensified Azores high pressure, which also extended to the east-northeast and abnormal low monthly mean surface pressure over northern Russia and in the southeast of the EFAS domain. Precipitation totals were above normal in the north and below normal in the middle and the south of the EFAS domain, except for some regions with high impact precipitation events. The monthly mean air temperature was above normal in most parts of the EFAS domain.

At the beginning of September, a low-pressure system over the Norwegian Sea brought large-scale precipitation to central and eastern Europe. In the next days, a low-pressure system developed south of Iceland and moved via Great Britain and Ireland and the North Sea to northern Scandinavia. Simultaneously, several heavy precipitation events caused flash floods in Algeria and Morocco. Nearly the whole EFAS domain was influenced by high-pressure systems in the following days. An upper-level low-pressure system developed over Central Europe and brought again large-scale precipitation. As the high-pressure situation persisted, another upper-level low-pressure system was cut-off west of Great Britain and moved via France to the western Mediterranean region. It caused intense precipitation events mainly in Spain (including floods and landslides) and Algeria, but also in Southern France, Tunisia and Morocco. At the same time, a low-pressure system developed around Newfoundland and moved via the Atlantic Ocean and Iceland to Scandinavia. High precipitation totals caused floods in Western Norway. The low-pressure system stayed over Northern Russia for the next days and led to precipitation there. In addition, intense precipitation events were reported from Greece, Turkey and the eastern coast of the Adria. In the last days of September, several low-pressure systems moved via Great Britain and brought a lot of rain with subsequent floods.

In September 2019, the highest precipitation totals were observed in Norway, Great Britain, Spain and the east coast of the Black Sea (Figure 1). No precipitation fell in the southeastern parts of the EFAS domain and in some parts of Turkey, Greece, Romania, Morocco and Algeria. Due to the predominant high-pressure systems, most parts of the EFAS domain received less than normal precipitation amounts (Figure 2). More than normal precipitation amounts were observed in parts of Spain, Tunisia, Algeria and Morocco due to some days with heavy precipitation and many regions in the north and east of the EFAS domain.

The monthly mean temperature ranged from -5.4°C to 36.8°C with the highest temperatures in the southern parts and lowest temperatures in the northern and mountainous parts of the EFAS domain (Figure 3). Temperature anomalies ranged from -4.3°C to 9.9°C with abnormally low temperatures in the eastern parts of the EFAS domain, Scandinavia, Portugal, Morocco and Algeria (Figure 4). Temperatures rose above normal in nearly all other regions.