Monthly mean maps for precipitation and temperature (observed and anomaly) with a summary of the monthly meteorological situation


This analysis is based on observational data of precipitation and temperature. For a monthly analysis based on ERA5 reanalysis, please see the Climate bulletins produced by Copernicus Climate Change Service

Meteorological situation for December 2018

Figure 1. Accumulated precipitation [mm] for December 2018.
Figure 1. Accumulated precipitation [mm] for December 2018.
Figure 2. Precipitation anomaly [%] for December 2018, relative to a long-term average (1990-2013). Blue (red) denotes wetter (drier) conditions than normal.
Figure 2. Precipitation anomaly [%] for December 2018, relative to a long-term average (1990-2013). Blue (red) denotes wetter (drier) conditions than normal.
Figure 3. Mean temperature [°C] for December 2018.
Figure 3. Mean temperature [°C] for December 2018.
Figure 4. Temperature anomaly [°C] for December 2018, relative to a long-term average (1990-2013). Blue (red) denotes colder (warmer) temperatures than normal.
Figure 4. Temperature anomaly [°C] for December 2018, relative to a long-term average (1990-2013). Blue (red) denotes colder (warmer) temperatures than normal.

by EFAS Meteorological Data Collection Centre

The meteorological situation in December 2018 was more versatile than in the month before. The first 10 days of the month were characterized by the northward shifted Azores high pressure system, which caused low precipitation totals in northwestern Africa and the Iberian Peninsula. An intense cyclonic activity was observed northward of this high pressure system. Two larger low-pressure systems moved from the Atlantic Ocean via Britain and Ireland and the North Sea to Scandinavia causing strong winds and intense large-scale precipitation events. A small low-pressure system in the Eastern Mediterranean region caused several floods in this region.

In mid-month, the above mentioned high-pressure system split into two systems, where the northern moved via Scandinavia to northwestern Russia. A small low-pressure system dropped off in the western Mediterranean region. Later, another low-pressure system moved from the Atlantic Ocean to Britain and Ireland and caused large-scale precipitation amounts in western and central Europe. The end of December was characterized by a stable high-pressure system over southwestern and central Europe. Intense precipitation events occurred in the eastern Mediterranean region.

In December 2018 precipitation amounts were up to 700 mm/month. The highest amounts were observed in the eastern Mediterranean Region, Britain and Ireland, the west coast of Norway, northwestern Iberian Peninsula and the Alps (Figure 1). Notable is the large gradient in precipitation totals between the Alps and northern Italy. Large positive precipitation anomalies were in the eastern Mediterranean region but also in central and eastern Europe (Fig 2). Largest negative anomalies occurred in northwestern Africa, the Iberian Peninsula and south of the Alps.

Most regions had positive temperature anomalies (Fig 3-4). Negative temperature anomalies are found in western Russia, parts of Scandinavia, southern Portugal, the Balkans and around the Aegean Sea.