  Space weather is a matter of practical importance in our modern society.
Predictions of forecoming solar cycles mean amplitude and duration are
currently being made based on flux-transport numerical models of the solar
dynamo. Interested in the forecast horizon of such studies, we quantify the
predictability window of a representative, advection-dominated, flux-transport
dynamo model by investigating its sensitivity to initial conditions and control
parameters through a perturbation analysis. We measure the rate associated with
the exponential growth of an initial perturbation of the model trajectory,
which yields a characteristic time scale known as the e-folding time $\tau_e$.
The e-folding time is shown to decrease with the strength of the
$\alpha$-effect, and to increase with the magnitude of the imposed meridional
circulation. Comparing the e-folding time with the solar cycle periodicity, we
obtain an average estimate for $\tau_e$ equal to 2.76 solar cycle durations.
From a practical point of view, the perturbations analysed in this work can be
interpreted as uncertainties affecting either the observations or the physical
model itself. After reviewing these, we discuss their implications for solar
cycle prediction.
