ANNUAL PRECIPITATION IN THE NORTHEAST UNITED-STATES - LONG MEMORY, SHORT-MEMORY, OR NO MEMORY

Regional filtering and intervention analysis of nineteen 100‐year precipitation series from the northeast United States indicate that eight of these series are of doubtful homogeneity. Statistics of these series are generally distorted. Of particular significance is the inflation of the short‐lag autocorrelation function and Hurst coefficient. For the precipitation series which appear to be homogeneous the estimated autocorrelation functions and Hurst coefficients are remarkably consistent with a lag l autoregressive process, indicating that annual precipitation in the northeast United States is a short‐memory process. Based on these results, it is recommended that before long‐term memory is inferred from analyses of hydrologic series, the homogeneity of these series should be clearly established. Copyright 1979 by the American Geophysical Union.