  The control of Covid 19 epidemics by public health policy in Italy during the
first and the second epidemic waves has been driven by using reproductive
number Rt(t) to identify the supercritical (percolative), the subcritical
(arrested), separated by the critical regime. Here we show that to quantify the
Covid-19 spreading rate with containment measures (CSRwCM) there is a need of a
3D expanded parameter space phase diagram built by the combination of Rt(t) and
doubling time Td(t). In this space we identify the dynamics of the Covid-19
dynamics Italy and its administrative Regions. The supercritical regime is
mathematically characterized by i) the power law of Td vs. [Rt(t)-1] and ii)
the exponential behaviour of Td vs. time, either in the first and in the second
wave. The novel 3D phase diagram shows clearly metastable states appearing
before and after the second wave critical regime. for loosening quarantine and
tracing of actives cases. The metastable states are precursors of the abrupt
onset of a next nascent wave supercritical regime. This dynamic description
allows epidemics predictions needed by policymakers to activate
non-pharmaceutical interventions (NPIs), a key issue for avoiding economical
losses, reduce fatalities and avoid new virus variant during vaccination
campaign
