I claim the ornamental design for a storage carousel, as shown and described.
FIG. 1 is a perspective view of a storage carousel, showing my new design;
FIG. 2 is a front elevational view of the invention;
FIG. 3 is a rear elevational view of the invention;
FIG. 4 is a left-side elevational view of the invention;
FIG. 5 is a right-side elevational view of the invention;
FIG. 6 is a top plan view of the invention; and,
FIG. 7 is a bottom plan view of the invention.
The broken line showing two substantially planar objects in FIG. 1 is included for the purpose of illustrating the device in use, and forms no part of the claimed design.