Atmospheric conditions at the onset of the December 2014 flood in Schleswig-Holstein, Germany, are described. Results show that the antecedent precipitation index (API) is able to reflect soil moisture conditions and, in combination with the maximum 3–day precipitation sum (R3d), to capture the main drivers ultimately leading to this flood. Trend analyses indicate an increasing risk of flood-prone situations over the last decades in this region. Further analyses are planned at the German coasts.