  We examine the validity of the $\Lambda$CDM model, and probe for the dynamics
of dark energy using latest astronomical observations. Using the $Om(z)$
diagnosis, we find that different kinds of observational data are in tension
within the $\Lambda$CDM framework. We then allow for dynamics of dark energy
and investigate the constraint on dark energy parameters. We find that for two
different kinds of parametrisations of the equation of state parameter $w$, a
combination of current data mildly favours an evolving $w$, although the
significance is not sufficient for it to be supported by the Bayesian evidence.
A forecast of the DESI survey shows that the dynamics of dark energy could be
detected at $7\sigma$ confidence level, and will be decisively supported by the
Bayesian evidence, if the best fit model of $w$ derived from current data is
the true model.
