  Electron skew scattering by impurities is one of the major mechanisms behind
the anomalous Hall effect in ferromagnetic nanostructures. It is particularly
strong at the surface of topological insulators where electron dynamics is
governed by the spin-1/2 Dirac equation. Motivated by recently discovered
mappings between hydrodynamics and the spin-1 Dirac equation, we consider the
scattering of plasma waves -- propagating charge density oscillations --
excited in graphene off a non-uniform magnetic field created by an adjacent
circular micromagnet. The calculated scattering amplitude not only exhibits a
giant asymmetry, or skewness, but is resonantly enhanced if the frequency of
the incoming wave matches the frequency of the chiral trapped mode circulating
the micromagnet in only one direction. Furthermore, if the frequency of the
incoming plasma wave is a few times larger than the Larmor frequency, the
angular distribution of its forward scattering is almost indistinguishable from
that of a Dirac electron at the surface of a topological insulator scattering
off a magnetic impurity. The micrometer scale of the proposed setup enables
direct investigations of individual skew scattering events previously
inaccessible in electronic systems.
