  We compute systematically the probability for fluctuations of the Higgs
field, averaged over a given spatial scale, to exceed a specified value, in the
Standard Model. For the particular case of interest of averages over one
coherence volume we show that, even in the worst possible case of taking the
one-loop improved effective potential parameters, the probability for the field
to fluctuate from the symmetric to the asymmetric minimum before the latter
becomes stable is very small for Higgs masses of the order of those of the $W$
and $Z$ bosons, whereas the converse is more likely. As such, metastability
should be satisfied dynamically at the Electroweak phase transition and its
dynamics should therefore proceed by the usual mechanism of bubble nucleation
with subcritical fluctuations playing no particularly relevant role in it.
