STAT In the literature: open

Lead-time limits for forecasting extreme events in chaotic systems

In plain words

Even with a perfect model, an extreme event can be forecast only some time ahead, set by how errors grow. The open question is how this lead time compares with the ordinary forecast limit, and whether rare events are more or less predictable than typical ones.

Precise statement

For a chaotic system with known equations (Kolmogorov flow, high-dimensional Lorenz-96) and initial uncertainty $\delta_0$, determine the maximal lead time at which events of an observable above its 99.9th percentile can be forecast with given precision and recall, in units of the inverse maximal Lyapunov exponent, and its relation to finite-time Lyapunov exponents along precursor trajectories. An answer is a scaling law for lead time versus $\delta_0$ and event size.

What would settle it

Ensemble forecasts in model flows at several $\delta_0$ and thresholds, matched by a theory based on finite-time instabilities.

Status in the literature

Unverified note

A 2024 study examines limits to extreme-event forecasting in model chaotic flows (arXiv:2401.16512).

See also