Professor Sanders will conduct synoptic research in three areas through analysis of observations. The first is the development of organized systems of deep cumulonimbus clouds, which produce many dangerous and damaging phenomena ranging from heavy rain to tornadoes. Professor Sanders will study where, when, and why they form, in and near the United States, using existing hourly maps over two to three years of persistent intense radar echoes, and using a special set of sounding and other data in the central United States for a particular case. The second is the development of frontal systems, both near the surface and in the higher tropospheric levels. Professor Sanders will look at a form of sloping roll circulation that often develops as part of the process of frontal formation and is responsible for lines of heavy rainfall with little precipitation between and for alternating vertical layers of saturated and very dry air. The third is a further study of the development of cyclonic storms near the surface. Both the initial formation aloft and the later influence on events at low levels will be examined.