The Intermountain Precipitation Experiment

Web Resources:

Steenburgh's Lake-effect diagnostics web page

Watch, Warning, and Advisory Criteria

Utah Area Mesonet (University of Utah)

Salt Lake City National Weather Service Forecast Office

Western Region Headquarters

Selected topics on the synoptic and mesoscale weather of the western United States: Schultz 1997 (SPC Winter Weather Training Materials)

From the above:
Composite analyses showed that well-defined events were associated with the passage of a mobile upper-level trough and associated cold front with lake-effect precipitation occurring in the post-frontal westerly, northwesterly, or northerly flow. 64% of the individual events closely match this evolution. The remaining cases also feature the intrusion of cold-air and the development of westerly to northerly flow over northern Utah, but exhibit varying types of upper-level flow evolution.

Web sites below are very useful for identifying these patterns.

Salt Lake City Snowstorm Climatology (SLC WSFO)
Cedar City, UT Snowstorm Climatology (SLC WSFO)
Logan, UT Snowstorm Climatology (SLC WSFO)
Utah Snowstorm Case Studies (Univ. of Utah)

Salt Lake Valley Lake-Effect Snow

Carpenter (1993) examined lake-effect snowstorms which affected Salt Lake City. They typically occurred during the spring and fall when 700-mb air and lake temperatures were largest. Usually they occurred in the morning hours suggesting local enhancement by drainage circulations from the surrounding mountains may be playing a role. The exact mechanisms responsible are currently being investigated by the University at Utah and the SLC Weather Service Forecast Office.

Onton and Steenburgh: Abstract on Lake-effect snows and animation of snowbands

Analysis Tools

Sectorized "Lake" Diverence calculations (Mike Splitt)

Winter Forecasting - Utah Style

Larry Dunn (SOO, SLC WSFO) has written a web document describing snow and freezing drizzle forecasting, among other topics. It also describes specific techniques for diagnosis.

Required Reading:

Steenburgh et al., 1999: Climatology of lake-effect snowstorms of the Great Salt Lake. Mon. Wea. Rev. in press.

Carpenter, 1993: The lake effect of the Great Salt Lake: Overview and forecast problems. Wea. Forecasting, 8, 181-193.

Schultz, D. M., 1999: Lake-effect snowstorms in northern Utah and western New York with and without lightning. Weather and Forecasting, in press.

Cooper et al., 1994: "Big versus super" snowfall events at Salt Lake City, UT: A composite comparison. Western Region Tech. Attach. No. 94-37.

Suggested Reading:

Onton 1999: An Observational and Numerical Modeling Investigation of Great Salt Lake-Effect Snow. PhD thesis, University of Utah, 126 pp.

Ciliberti et al., 1999: An analysis of a cold frontal passage over complex terrain in northwest Utah.

Dunn, 1983: Quantitative and spatial distribution of winter precipitation along Utah's Wasatch Front. NOAA Tech. Memo. NWS WR-181.

Other Reading:

Horel and Gibson, 1994: Analysis and simulation of a winter storm over Utah. Wea. Forecasting, 9, 479-494.

Long et al., 1990: Investigations of a winter mountain storm in Utah. Part I: Synoptic analyses, mesoscale kinematics, and water release rates. J. Atmos. Sci., 47, 1302-1322.

Sassen et al., 1990: Investigations of a winter mountain storm in Utah. Part II: Mesoscale structure, supercooled liquid water development, and precipitation processes. J. Atmos. Sci., 47, 1323-1350.

Last revised: 31 October 2000 DMS