  The present note is devoted to the studies of the relation of the time-zero
limits of Kaden's spirals and the 2D Euler equation. It is shown that the
time-zero limits of Kaden's spirals satisfy inhomogeneous 2D Euler in a weak
sense. As a corollary, the necessity of both, the decay of spherical averages
around the origin of the spiral as well as the velocity matching condition, for
the 2D Euler equation to hold in a weak sense, is shown. Finally, some
preliminary results concerning the Kaden spirals are obtained.
