  We study the connection between extreme events of thermal and kinetic energy
dissipation rates in the bulk of three-dimensional Rayleigh-B\'{e}nard
convection and the wall shear stress patterns at the top and the bottom planes
that enclose the layer. Zero points of this two-dimensional vector field stand
for detachments of strong thermal plumes. If their position at the opposite
planes and a given time is close then they can be considered as precursors for
high-amplitude bulk dissipation events triggered by plume collisions or close
passings. This scenario requires a breaking of the synchronicity of the
boundary layer dynamics at both plates which is found to be in line with a
transition of the bulk derivative statistics from Gaussian to intermittent. Our
studies are based on three-dimensional high-resolution direct numerical
simulations for moderate Rayleigh numbers between $Ra=10^4$ and $5\times 10^5$.
