To forecast tropical cyclones, or to determine possible changes in their climatology as a result of global warming, we need a conceptual model of how tropical cyclones work.

• How do tropical cyclones form, intensity, and decay?
• Why do these storms sometimes intensify rapidly, surprising tropical forecasters in charge of protecting life and property for communities affected by these life-threatening storms?
• What conceptual models are available to address the questions?

In this talk I will briefly review tropical cyclone structure and present new developments on the fluid dynamics of these storms that help answer these questions.