Time series representing two of the climate systems most prominent patterns of variability, namely El Nino-Southern Oscillation (ENSO), and the Arctic Oscillation (AO), are used together with observed daily precipitation data over the conterminous United States to diagnose relationships between climate variability and winter precipitation extremes.The study highlights the connections between ENSO, the AO and the combined effects of ENSO and the AO and the statistics of daily precipitation events (e.g. frequency/intensity/geographic distribution). Large-scale circulation features associated with extreme precipitation events in the most sensitive regions are examined in detail. Emphasis is placed on linkages between daily precipitation and climate variability that meteorological models must be able to simulate in order to be deemed credible for use in weather forecasts and assessments.