Assigning precipitation to mid-latitudes fronts on sub-daily scales in the North Atlantic and European sector: Climatology and trends
Hénin R, Ramos AM, Schemm S, Gouveia CM, Liberato MLR
Int J Climatol.2018;1–14, https://doi.org/10.1002/joc.5808
Atmospheric fronts are fundamental features of the weather variability in the mid-latitudes and are frequently associated with high-impact weather events such as hail, wind gusts or precipitation. A method to link precipitation with synoptic-scale fronts on sub-daily timescales is developed based on ERA-Interim data (1979–2016). A case study, a climatology and a trend analysis are presented and discussed. Spatially, an optimal attribution radius is identified based on a random sampling technique. The method is demonstrated using a past weather event that occurred over western Europe. Annual and seasonal cycles are presented and confirm, in agreement with previous studies, that frontal precipitation accounts for a large fraction of all precipitation (up to 80%) in the mid-latitudes, especially during autumn and winter. Finally, a negative trend in frontal precipitation is identified, mostly affecting the Gulf Stream region. Cold fronts drive most of the observed trends in this region and the trend pattern suggests a polewards displacement of the zone of enhanced precipitation.