  We examine the outer Galactic HI disk for deviations from the b=0 plane by
constructing maps of disk surface density, mean height, and thickness. We find
that the Galactic warp is well described by a vertical offset plus two Fourier
modes of frequency 1 and 2, all of which grow with Galactocentric radius.
Adding the m=2 mode accounts for the large asymmetry between the northern and
southern warps. We use a Morlet wavelet transform to investigate the spatial
and frequency localization of higher frequency modes; these modes are often
referred to as "scalloping." We find that the m=10 and 15 scalloping modes are
well above the noise, but localized; this suggests that the scalloping does not
pervade the whole disk, but only local regions.
