MONTHLY TEMPERATURE AND PRECIPITATION FIELDS ON A STORM-FACING MOUNTAIN FRONT - STATISTICAL STRUCTURE AND EMPIRICAL PARAMETERIZATION

This paper presents an analysis of monthly temperature (T) and precipi tation (P) time series at 28 climatologic stations on the storm-facing slope of the Wasatch Range, Utah. The goal is to examine the space-ti me structure of T and P and to develop an empirical model incorporatin g both seasonal and elevation effects. Each time series (T or P) is de composed into the sum of a long-term mean, a seasonal cycle, and a res idual random process. The seasonal cycle is well determined by the amp litude and phase of a few harmonics, and the residual noise is approxi mated by a power law form of the variance spectrum. Empirical correlat ions are found relating the temporal moments of altitude, allowing the construction of a parametric T-P model as a function of altitude and season. The observed correlations are discussed within the context of the region's synoptic weather patterns. When combined with digital ele vation data, the model can be used to estimate seasonal temperature an d precipitation fields as input to mountain front hydrologic studies.