El Niño/Southern oscillation signals in the long term climate of Donner Summit, California

The latest El Nino event has prompted questions about the predictability of North American weather based on therelative strength of the Southern Oscillation Index (SOl). The annual precipitation, snowfall, and air temperature data from an area near Donner Pass, California have been analyzed in comparison with the SOI from the equatorial Pacific Ocean. There was found to be a positive correlation between decreasing SOl values and increasing annual precipitation; a positive correlation between increasing SOl values and increasing annual snowfall; and a positive correlation between increasing SOl values and increasing average annual air temperature. All these correlations, however, are weak. 64 % of the wettest years on record occurred with alow SOl, and 52% of the driest years on record occurred with a high SOl. Data was available from 1900 through 1997 excluding 1907, 1908, 1914, 1915, and 1932.