A couple of months ago I was reading NOAA reports on El Nino regarding the SW area and the reports showed a whole lot of winter conditions following Nino, even though Nino's passed. I was very skeptical at first, but it looks like it's completely accurate.
They mentioned something called the North Atlantic Oscillation...a counter-clockwise wind pattern that's centered in the east-ward area of the United States. This "fan" is pushing El Nino further south while giving the Southwest the weather from the central north....which is a lot of snow and rain. La Nina is a long ways out...and I hope will never come back.