  We propose a new procedure to monitor and forecast the onset of transitions
in high dimensional complex systems. We describe our procedure by an
application to the Tangled Nature model of evolutionary ecology. The
quasi-stable configurations of the full stochastic dynamics are taken as input
for a stability analysis by means of the deterministic mean field equations.
Numerical analysis of the high dimensional stability matrix allows us to
identify unstable directions associated with eigenvalues with positive real
part. The overlap of the instantaneous configuration vector of the full
stochastic system with the eigenvectors of the unstable directions of the
deterministic mean field approximation is found to be a good early-warning of
the transitions occurring intermittently.
