  A dynamical system is said to undergo rate-induced tipping when it fails to
track its quasi-equilibrium state due to an above-critical-rate change of
system parameters. We study a prototypical model for rate-induced tipping, the
saddle-node normal form subject to time-varying equilibrium drift and noise. We
find that both most commonly used early-warning indicators, increase in
variance and increase in autocorrelation, occur not when the equilibrium drift
is fastest but with a delay. We explain this delay by demonstrating that the
most likely trajectory for tipping also crosses the tipping threshold with a
delay and therefore the tipping itself is delayed. We find solutions of the
variational problem determining the most likely tipping path using numerical
continuation techniques. The result is a systematic study of the most likely
tipping time in the plane of two parameters, distance from tipping threshold
and noise intensity.
