  We find that convective regions of collapsing massive stellar cores possess
sufficient stochastic angular momentum to form intermittent accretion disks
around the newly born neutron star (NS) or black hole (BH), as required by the
jittering-jets model for core-collapse supernova (CCSN) explosions. To reach
this conclusion we derive an approximate expression for stochastic specific
angular momentum in convection layers of stars, and using the mixing-length
theory apply it to four stellar models at core-collapse epoch. In all models,
evolved using the stellar evolution code MESA, the convective helium layer has
sufficient angular momentum to form an accretion disk. The mass available for
disk formation around the NS or BH is 0.1-1.2Mo; stochastic accretion of this
mass can form intermittent accretion disks that launch jets powerful enough to
explode the star according to the jittering-jets model. Our results imply that
even if no explosion occurs after accretion of the inner ~2-5Mo of the core
onto the NS or BH (the mass depends on the stellar model), accretion of outer
layers of the core will eventually lead to an energetic supernova explosion.
