Numerical simulation of mesoscale structures in the northern alpine foreland during front passages: A precipitating cold front without pre-frontal foehn

Abstract

Supplementing a previous study of a dry cold front with pre-frontal foehn (Heimann 1992c) this paper documents the numerical simulation of a precipitating cold front approaching the Alps from northwest without pre-frontal foehn. A passive nesting scheme allows a detailed inspection of mesoscale patterns in southern Bavaria. The results are discussed with reference to observations of a real front taken during the German Front Experiment 1987. Significant mesoscale patterns do qualitatively agree with observed structures. The discussion focusses on the changing appearance of these patterns as the front approaches the Alps. It was found that the intensity of precipitation increases as the frontal and orographic lifting fields merge. The low-level jet ahead of the front disappears when the front impinges on the Alps.

Keywords

• pre-frontal
• foehn
• nesting scheme
• german front experiment
• bavaria
• alps
• präfrontal
• föhn
• nestungsschema
• deutsches frontexperiment
• bayern
• alpen
• germany