Climate anomalies based on El Nino is inherently probabilistic. It won't *always* lead to the expected impact (sometimes it will be opposite), but, for some regions, *most of the time* it should lead to the expected impact.  Unfortunately the El Nino-less snowfall relationship (in the Pac NW) seems to be one of the more robust signals.  https://www.climate.gov/news-features/blogs/snow-pain-snow-gain-how-does-el-nino-affect-snowfall-over-north-america