Climatology of Wet and Dry Cycles in Utah

Much of the Great Basin experiences highly variable temperature and precipitation patterns in both space and time. A distinctive feature is the somewhat binary nature of temporal variations of precipitation. The yearly precipitation tends to cluster around two states, one wet and the other dry. Indeed, the temporal nature of precipitation is not random, yet not completely organized. Mean values will be misleading under such a regime. An absence of imagination and creativity in the enterprise of reporting climate data has left us with the use of 30 year averages, that are sometimes of questionable value. Since the temporal variations in precipitation have such a dominant effect on the water resources of this region, other quantitative analyses may be of value. The general goal of our study is to look more closely at the dry and wet cycles of precipitation in Utah. Various analyses will be explored. These include; pdfs of the wet and dry periods, their intensity, and how long they persist; power spectra and cross spectra of precipitation and temperature data; and analyses of the memory of the system. In addition, a long-term goal is to explore the connections between large-scale features of the atmosphere and ocean circulations, and the observed wet and dry cycles. Here we will document the behavior of climate in this region, and report some preliminary results for a few stations in northern Utah. Some early findings of the importance of various cycles in the climate will be presented