  In rotating Rayleigh-B\'enard convection, columnar vortices advect
horizontally in a stochastic manner. When the centrifugal buoyancy is present
the vortices exhibit radial motions that can be explained through a
Langevin-type stochastic model. Surprisingly, anomalous outward motion of
cyclones is observed in a centrifugation-dominant flow regime, which is
contrary to the well-known centrifugal effect. We interpret this phenomenon as
a symmetry-breaking of both the population and vorticity magnitude of the
vortices brought about by the centrifugal buoyancy. Consequently, the cyclones
submit to the collective vortex motion dominated by the strong anticyclones.
Our study provides new understanding of vortex motions that are widely present
in many natural systems.
