Recently, NOAA stated in their newest bulletin, very accurately, that El Nino was finished as of June 9th. These transitions don't occur instantly. The transition away from El Nino toward La Nina has been ongoing for months.
The region used in determining the state of the equatorial Pacific is the ENSO 3.4 region.
All Nino regions (especially the key Nino 3.4 region) temperatures have been falling since the start of the year.
This animation showing the ocean temperatures vs normal values show this perfectly. See the cooler water on the right side (east).
A larger spherical look at the ocean temperatures show the transition even better starting in January. The last image is what the mature La Nina looked like in January of 1999.
It takes months for the effects of any ENSO state (El Nino, neutral or La Nina) to be reflected in the atmosphere. So its very difficult to predict at this time what the winter will be like for specific locations. But we can perform some basic albeit general statistical comparisons between snowfall and La Nina.
Using the ERSSTv4 ocean temperature dataset, a list of La Nina strengths can be determined. Hat tip to Eric Webb.
Based on these years and rankings, I matched up our Cleveland snowfall for these La Nina years. Here is what I found. The majority of these years had ABOVE NORMAL SNOWFALL in Cleveland!
This is no guarantee of above normal snowfall during the winter of 2016-17 as there are other factors yet to be determined.
Last year, I posted my thoughts on the upcoming winter (2015-16) around Labor Day. Expect some more detailed thoughts on the effects of La Nina on the upcoming winter of 2016-17 around the same time this year. Until then, let's enjoy summer!