Science Source

Peak precipitation intensity in relation to atmospheric conditions and large-scale forcing at midlatitudes

Presents a statistical analysis of the relation between large-scale conditions and hourly precipitation at midlatitudes, by using observations of the Netherlands combined with a regional reanalysis
Aims to gain a better understanding of the typical large-scale atmospheric conditions and large-scale forcing associated with extreme hourly precipitation and determine the typical differences between cases of extreme precipitation and weaker events
Performs an event-based analysis, to avoid double-counting, and considers the hourly peak intensity, rather than all hourly data
Finds that atmospheric large-scale profiles consistently show a clear separation between precipitation deciles, characterized by increasing instability and moisture content of the atmosphere for more extreme precipitation
Finds stronger events are characterized by larger atmospheric forcing preceding the event, which primarily relates to vertical motions
Analyzes—based on these results—four atmospheric parameters, describing atmospheric moisture, stability and large-scale convergence as potential indicators of strong precipitation events
Finds their correlations are weak despite positive relations between these parameters and the peak intensity