Hi, there are a number of options for scoring the ENSO forecasts. One possibility is to use the forecasts issued by various centers and shown in the IRI/CPC ENSO prediction plume since 2002. Forecasts for 3-month SST anomaly in the Nino3.4 region (often used as the SST aspect of ENSO) are shown in the file found at: http://iri.columbia.edu/~forecast/ensofcst/Data/ and then click on the second link in the list. These show departures from average (anomalies), not actual SST. A list of many models is shown for each foreast start time, from 2002 until April 2017. The numbers are given in hundredths of degree C. The lead time increases as you move to the right in each row. The 3-month season in the first and the last column is given in the heading text for each set of forecasts. The models change over time -- some quit, some change version number, and some new ones come along. Now, for the observations, you can use NOAA's SST observations, and there's more than one SST dataset. The one I often use is the one given in the table on the site: http://www.cpc.ncep.noaa.gov/data/indices/sstoi.indices which gives 1-month SST and SST anomaly. The data for the Nino3.4 region is farthest to the right. Another possible SST dataset from NOAA is found at http://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt and this one is already averaged into 3-month periods for you, saving you the trouble of doing that, and it is only for Nino3.4 region. If you do not want to verify these model forecasts, but want to verify the CPC/IRI monthly ENSO probabilistic forecasts, you only have several years of these. If you do want those, please e-mail Michelle L'Heureux at Michelle.LHeureux@noaa.gov about obtaining those. At the web site: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory…  I only see the current Discussion and forecast, and don't know how to get older ones going back to 2011 or 2012 or so. Good luck with your scoring project!