Foehn flow and stable air mass in the Rhine valley: The beginning of a MAP event

• Published in: Quarterly journal of the Royal Meteorological Society Vol. 130; no. 597B; pp. 541 - 560
• Main Authors: Beffrey, G, Jaubert, G, Dabas, A
• Format: Journal Article
• Language: English
• Published: 01.01.2004
• Subjects: Europe, Rhine R
• ISSN: 0035-9009
• DOI: 10.1256/qj.02.228

The foehn event of the 8th Intensive Observation Period (20-21 October 1999) of the Mesoscale Alpine Programme is examined at small scale with the help of both instrumental data (especially from a ground-based Doppler lidar) and of high-resolution simulation performed with the non-hydrostatic model meso-NH. The three-dimensional characteristics of the flow in the Rhine valley at the beginning of the event are studied. Special attention is given to the interaction between the foehn and a stable air mass, whose presence drives the penetration of the warm and turbulent foehn air to the ground. A quantification of the simulated features of the flow is given in terms of mass budgets over the target area, and a three-dimensional picture representing the arrival of the foehn air.