In the last few years a good deal of scientific attention and work has been
devoted to trying to understand the physical causes and mechanism of
anomalous circulation in the atmosphere. As often happens in meteorology,
most of the effort has been addressed to posing the right questions to be
answered. At the end of August 1984, a workshop was organized in Rome,
bringing together most of the leading experts in the field, with the purpose of
summarizing and clarifying the scientific results obtained thus far. The central
question for the workshop was as follows: does there exist a possible
physically sound definition of anomalous circulation or blocking, and if so
which processes are connected to the development and decay of anomalous
flows so defined?