Contributions of Lake-Effect Periods to the Cool-Season Hydroclimate of the Great Salt Lake Basin

• Published in: Journal of applied meteorology and climatology Vol. 52; no. 2; pp. 341 - 362
• Main Authors: Yeager, Kristen N., Steenburgh, W. James, Alcott, Trevor I.
• Format: Journal Article
• Language: English
• Published: Boston, MA American Meteorological Society 01-02-2013
• Subjects: Aquatic ecosystems; Climatology; Datasets; Disaggregation; Earth, ocean, space; Environmental conditions; Estimates; Exact sciences and technology; External geophysics; Freshwater; Gauges; Hydroclimate; Influence; Lake basins; Lakes; Meteorology; Meteors; Monthly distribution; Mountains; Precipitation; Precipitation estimation; Precipitation gauges; Radar; Radar echoes; Radar imagery; Radar imaging; Radar tracking; Salt lakes; Seasons; Shorelines; Snow; Snow-water equivalent; Snowpack; Storms; Telemetry; Topography; Water in the atmosphere (humidity, clouds, evaporation, precipitation); Weather forecasting; Winter; Great Salt Lake; United States; Utah; Lake Michigan; Great Lakes of North America; United States > US; USA, Utah, Great Salt L; USA, Utah; desagregation; coastal effects; salt lakes; hydrology; atmospheric precipitation; snow; Water equivalent; Radar imaging; telemetry; North America; Hydroclimatology
• ISSN: 1558-8424; 1558-8432
• DOI: 10.1175/JAMC-D-12-077.1

Although smaller lakes are known to produce lake-effect precipitation, their influence on the precipitation climatology of lake-effect regions remains poorly documented. This study examines the contribution of lake-effect periods (LEPs) to the 1998–2009 cool-season (16 September–15 May) hydroclimate in the region surrounding the Great Salt Lake, a meso-β-scale hypersaline lake in northern Utah. LEPs are identified subjectively from radar imagery, with precipitation (snow water equivalent) quantified through the disaggregation of daily (i.e., 24 h) Cooperative Observer Program (COOP) and Snowpack Telemetry (SNOTEL) observations using radar-derived precipitation estimates. An evaluation at valley and mountain stations with reliable hourly precipitation gauge observations demonstrates that the disaggregation method works well for estimating precipitation during LEPs. During the study period, LEPs account for up to 8.4% of the total cool-season precipitation in the Great Salt Lake basin, with the largest contribution to the south and east of the Great Salt Lake. The mean monthly distribution of LEP precipitation is bimodal, with a primary maximum from October to November and a secondary maximum from March to April. LEP precipitation is highly variable between cool seasons and is strongly influenced by a small number of intense events. For example, at a lowland (mountain) station in the lake-effect-precipitation belt southeast of the Great Salt Lake, just 12 (13) events produce 50% of the LEP precipitation. Although these results suggest that LEPs contribute modestly to the hydroclimate of the Great Salt Lake basin, infrequent but intense events have a profound impact during some cool seasons.