  We study numerically and experimentally the impact of temporal randomness on
the formation of analogue optical blast-waves in nonlinear fiber optics. The
principle-of-operation is based on a two-components nonlinear interaction
occurring between a partially coherent probe wave co-propagating in a normally
dispersive optical fiber together with an orthogonally polarized intense short
pulse. The cross-polarized interaction induces a dual phase-singularity in the
probe profile which leads to the formation of two sharp fronts of opposite
velocities. An optical blast-wave is then generated and leads to an expanding
rarefication area surrounded by two dispersive shock waves which regularize the
shock onto the probe landscape. Here we focus our study on the impact of
randomness in the shock formation. In particular, we show that the lack of
coherence into the probe wave acts as a strong diffusive term, which is able to
hamper or inhibit the shock formation. Our experimental observations are
confirmed by numerical predictions based on a system of two incoherently
coupled nonlinear Schr{\"o}dinger Manakov equations.
