I'm glad to see El Nino back for winter 2017-18, because this is when the Jet stream stays up north near the U.S.-Canadian border, that mean that there would not be too many snowstorms, or no snow at all, like what happen during the winter of 2015-16. It may happen again during the winter of 2017-18, To me, I don't want to see La Nina, this is when the jet stream dips down toward the 48 contigious United States, creating the wavy pattern like this e.g., vvvv. causing the infamous dreaded polar vortex during Winter, when the trough of the jet stream pulls the dangerous artic air from the polar regions, to the mid latitudes, where the lower 48 of the United States, that is a reason I don't like about La Nina. With El Nino, the Jet Stream stays (or remains) in Canada, away from the lower 48 of the United States, keeping it in a straight line pattern, by keeping the cold frigid air away, protecting the major cities, and people in the lower 48.