Mesoscale Aspects of Extratropical Cyclones: An Observational Perspective

Abstract

The understanding of the mesoscale structure of frontal cyclones has, as shown in this review, benefited greatly from special mesoscale observations such as dropwindsondes and other measurements from aircraft. These observations are usually interpreted within the context of numerical weather prediction (NWP) model analyses based on the operational synoptic-scale observations. A few studies have also used high-resolution mesoscale models to assimilate the observations. Another tool for mesoscale analysis---and a major source of inspiration for this review---is imagery. This includes cloud and water-vapor imagery from satellites, especially geostationary satellites, and also precipitation imagery from ground-based radars, especially in networks. By providing the overall pattern of the mesoscale phenomena and an indication of the relationship to the larger-scale forcing, the imagery is invaluable for giving qualitative understanding of the processes at work. Often it provides the only clues as to what is happening on the mesoscale.