Understanding the interannual variability of Atlantic tropical cyclone
activity is extremely important. Such knowledge has clear implications for seasonal forecasting of tropical cyclone activity. Large scale environmental factors that affect convection and tropical cyclone development have been previously identified and include vertical wind-shear, local sea surface temperature and the thermodynamic state of the atmosphere. A question that remains is how do remote forcings determine the large-scale environment in which tropical cyclones develop? Previous statistical work has shown significant relationships between Sahelian rainfall and El Nino for example with the correlation being greatest for the Sahelian rainfall. The work presented here proposes that the forcings result in teleconnections that can be
interpreted in terms of eastward propagating Kelvin waves and westward
propagating Rossby waves. Results will be shown from an idealised model with prescribed heating illustrating the main ideas. This work will be compared with seasonal forecasts based on the UKMO unified model.