Will it be a record year for rain?
The rainfall of recent weeks has catapulted Germany from drought to flood risk. The amount of rain is already well above the long-term average in many places, as current data shows. Will a two-decade-old record be broken in 2023?
Cloudy rain clouds, one low following the next: Germany will be drowning in an unusually abundant wet period in the fall of 2023. After the droughts of recent years, rainfall would actually be welcome. However, the amount of rainfall is already causing serious problems in some regions.
In the west and south, for example, the consequences can no longer be overlooked: The wetness is puddling up in fields and meadows, and the water levels in streams and rivers are rising significantly. Individual areas on the Rhine, the Aller and the Danube are reporting a tense flood situation.
The vast majority of weather stations have already recorded significantly more precipitation than usual in the current year up to November: some stations are even well above the long-term average, as the map of Germany of the rainfall amounts measured so far shows.
The nationwide average rainfall is also above the multi-year average. In terms of precipitation, Germany has already exceeded its rainfall quota. According to data from the German Weather Service (DWD), an average of 788.9 liters per square meter had already fallen across all regions by mid-November. This is already more than the long-term average for the years 1961 to 1990 - even though there are still a good five potentially rainy weeks left until the end of the year.
By comparison, the German regional average for the whole of 2022 was only 669.1 liters per square meter. In the previous year, it was 801.1 liters. The long-term average is given in the DWD data for Germany as 788.9 liters. The rainiest year in the recent past was 2002: according to the DWD, an average of 1018.1 liters of rain fell nationwide.
Weather stations in the south are currently at the top of the rainfall rankings. Balderschwang in Bavaria, for example, has so far recorded just under 2500 liters. However, as it always rains a lot there, this is pretty much the usual amount of precipitation.
The yield in dry Quedlinburg in Saxony-Anhalt is much more modest at 650 liters. However, the World Heritage town is also located in the so-called rain shadow of the Harz Mountains. Nevertheless, the local weather station is currently recording the largest deviation from the normal annual total in Germany with around 160 percent of the measured rainfall.
Abundant rainfall is also reaching other European countries, as data from the southern side of the Alps shows. Lake Garda, by far the largest natural freshwater reservoir in the region, is recording rising water levels again after the summer drought.
Saarland wettest federal state, rain also in the Alps
Even though it has repeatedly been quite dry in the southwest in recent years, the last few weeks in particular have shown what masses of water can come from the sky there. In parts of Baden-Württemberg, around 450 liters of rain per square meter fell in the first two thirds of November.
However, Saarland can currently claim the title of wettest federal state. Here, over 1000 liters of rain per square meter have fallen on average so far. North Rhine-Westphalia is also far ahead in the race with almost 1000 liters. At the same time, it is also clear that Germany has finally been able to record a good amount of rain again since 2017.
Not everything reaches the ground in the form of rain. "In the mountains, some of the precipitation remains as snow," explains ntv meteorologist Björn Alexander. The water is trapped there for a longer period of time, which can provide some relief for regions threatened by flooding.
"But not too much more can happen in terms of flooding," warns Björn Alexander. "The soil is soaked, the upper layers can hardly absorb any significant amounts." In the lower areas, most of the rainfall in the coming weeks will run off above ground - increasing the risk of flooding.
Overall, however, the rainfall does have some positive aspects, as a look at the rainfall totals of recent years shows. The pronounced periods of drought and the extremely low rainfall in 2018 have thrown Germany's water balance out of kilter. On a moving average, rainfall over the past ten years is still far below the long-term average.
In short, much more rain would be needed overall to get vegetation and groundwater back on track. Hot summers and winters with little snow have noticeable consequences: There is a lack of water in nature. Forests and fields have dried out down to the deeper soil layers. It will take years for the subsoil to build up sufficient moisture again.
How much more rain can we expect?
"If we look at the experimental long-term forecasts, the picture is currently twofold," says the ntv meteorologist. "The calculations of the American weather service NOAA predict that December will also be much too wet." According to these calculations, we can expect another 90 to 100 liters of precipitation in the coming weeks.
The record amounts from 2002 are therefore unlikely to be exceeded on average across the country. The European weather model comes to completely different conclusions. Here, the forecasts point to a drier, but also often frosty December.
Source: www.ntv.de
