  We consider the quasinormal spectrum of scalar and axial perturbations of the
Reissner-Nordstr\"om-AdS black hole as the horizon approaches extremality. By
considering a foliation of the black hole by spacelike surfaces which intersect
the future horizon we implement numerical methods which are well behaved up to
and including the extremal limit and which admit initial data which is
nontrivial at the horizon. As extremality is approached we observe a transition
whereby the least damped mode ceases to be oscillatory in time, and the late
time signal changes qualitatively as a consequence.
