 This fact leads to the existence of a theoretical upper bound on the strongest wind speed that a tropical cyclone can attain.Because evaporation increases linearly with wind speed (just as climbing out of a pool feels much colder on a windy day), there is a positive feedback on energy input into the system known as the Wind-Induced Surface Heat Exchange (WISHE) feedback.This feedback is offset when frictional dissipation, which increases with the cube of the wind speed, becomes sufficiently large.