  In this paper we present the results of the statistical analysis of
high-latitude HI turbulence in the Milky Way. We have observed HI in the 21 cm
line, obtained with the Arecibo L-Band Feed Array (ALFA) receiver at the
Arecibo radio telescope. For recovering of velocity statistics we have used the
Velocity Coordinate Spectrum (VCS) technique. In our analysis we have used
direct fitting of the VCS model, as its asymptotic regimes are questionable for
Arecibo's resolution and given the restrictions from thermal smoothing of the
turbulent line. We have obtained a velocity spectral index $3.87 \pm 0.11$, an
injection scale of $140 \pm 80$ pc, and an HI cold phase temperature of $52 \pm
11$ K. The spectral index is steeper than the Kolmogorov index and can be
interpreted as being due to shock-dominated turbulence.
