  Determining the maximum potential limit in the accuracy of hurricane
intensity prediction is important for operational practice. Using the
phase-space reconstruction method for hurricane intensity time series, here we
found that hurricane dynamics contain inherent low-dimensional chaos at the
maximum intensity equilibrium. Examination of several chaotic invariants
including the largest Lyapunov exponent, the Sugihara-May correlation, and the
correlation dimension consistently captures an intrinsic dimension of the
hurricane chaotic attractor in the range of 4-5. In addition, the error
doubling time is roughly 1-5 hours, which accords with the decay time obtained
from the Sugihara-May correlation. The confirmation of hurricane chaotic
intensity as found in this study suggests a relatively short limit for
intensity predictability of $\sim$18-24 hours after reaching the maximum
intensity stage. So long as the traditional metrics for hurricane intensity
such as the maximum surface wind or the minimum central pressure is used for
intensity forecast, our results support that hurricane intensity forecast
errors will not be reduced indefinitely in any modelling systems, even in the
absence of all model and observational errors. As such, the future improvement
of hurricane intensity forecast should be based on different intensity metric
beyond the absolute intensity errors as in the current practice of intensity
verification.
