Meteorological satellite date have truly revolutionized tropical meteorology. In higher latitudes, satellite pictures led to no great fundamental surprises since the typical cloud distributions associated with fronts and extra-tropical cyclones had been determined from fairly dense surface networks. Satellite data have re-enforced the original polarfront concept with only a few modifications. Conversely, in the tropics, which has always been a sparse-data area, Satellite data have greatly increased our knowledge of the major cloud systems (e. g., their development, movement, In higher latitudes, satellite pictures led to no great fundamental surprises since the typical cloud distributions associated with fronts and extra-tropical cyclones had been determined from fairly dense surface networks. Satellite data have re-enforced the original polarfront concept with only a few modifications. Conversely, in the tropics, which has always been a sparse-data area, Satellite data have greatly increased our knowledge of the major cloud systems (eg, their development, movement,