Linking Large‐Scale Circulation Descriptors to Precipitation Variability in the Northern French Alps

Abstract

AbstractThis work analyses the link between Western Europe large‐scale circulation and precipitation variability in the Northern French Alps from 1950 to 2017. We consider simple descriptors characterizing the daily 500 hPa geopotential height fields. They are the maximum pressure difference (MPD)—representing the range of geopotential heights over Western Europe, and the singularity—representing the mean distance between a geopotential shape and its closest analogs, that is, the way this geopotential shape is reproduced in climatology. We show that the MPD and the singularity of geopotential shapes explain a significant part of precipitation variability in the Isère River catchment () from 10 days to 10 years, especially in winter (correlations of 0.7). These simple descriptors ‐ that are easy to implement—provide as much information as weather pattern classification and much better performance than North Atlantic Oscillation to explain precipitation variability over a medium size mountainous catchment.