  We describe results from the third stage of a project to build a statistical
model for hurricane tracks. In the first stage we modelled the unconditional
mean track. In the second stage we modelled the unconditional variance of
fluctuations around the mean. Now we address the question of how to model the
autocorrelations in the standardised fluctuations. We perform a thorough
diagnostic analysis of these fluctuations, and fit a type of AR(1) model. We
then assess the goodness of fit of this model in a number of ways, including an
out-of-sample comparison with a simpler model, an in-sample residual analysis,
and a comparison of simulated tracks from the model with the observed tracks.
Broadly speaking, the model captures the behaviour of observed hurricane
tracks. In detail, however, there are a number of systematic errors.
