title: Comment on "Nonparametric forecasting of low-dimensional dynamical systems ".
abstract: The comparison performed in Berry et al. [Phys. Rev. E 91, 032915 (2015)] between the skill in predicting the El Niño-Southern Oscillation climate phenomenon by the prediction method of Berry et al. and the "past-noise" forecasting method of Chekroun et al. [Proc. Natl. Acad. Sci. USA 108, 11766 (2011)] is flawed. Three specific misunderstandings in Berry et al. are pointed out and corrected.
authors.affiliation: Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave., Box 951565, 7127 Math Sciences Bldg., University of California, Los Angeles, California 90095-1565, USA.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Kondrashov
authors.affiliation: Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave., Box 951565, 7127 Math Sciences Bldg., University of California, Los Angeles, California 90095-1565, USA.
authors.forename: Mickaël D
authors.initials: MD
authors.lastname: Chekroun
authors.affiliation: Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave., Box 951565, 7127 Math Sciences Bldg., University of California, Los Angeles, California 90095-1565, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Ghil