Review of Previous Work: Great Lakes Studies

• Lake Effect snow elsewhere - - Great Lakes, USA
  
  
  • First described by Wiggin in 1950. 30+ journal articles since then.
    
    
  • Snowfall amounts vary by up to 80 cm over distances less than 10km
    
    
  • Single events can drop as much as 150-250 cm (sykes 1966)
    
    
  • Four types of lake-effect snowstorms(Braham and Kelly 1982,Braham 1983, Hjel mfelt 1990, and Niziol et al. 1995)
    • Broad area coverage with embedded open-cellular convection or multiple wind- parallel bands.
    • Mid-lake bands
    • Shoreline parallel bands
    • Mesoscale vortices
    
    
  • Influenced by:
    • lake-air temperature difference
    • wind speed, direction, shear
    • fetch
    • stability
    • "terrain"
  
  
  

  Review of Previous Work: GSL Studies

  
  
• Carpenter 1993
  • Identified cases based on visual observations and spotter reports
  • Found conditions associated with GSLE
    • lake-700 hPa temperature difference of at least 17 °C
    • 700 hPa wind direction 270 ° - 360 °
    • Upper Level Support such as:
      Jet Streak
      700 hPa Thermal Trough

      Minimum Capping Inversion between 700 - 650 hPa
  
  
• Steenburgh, Halvorson, and Onton 1998:
  • Fall 1994 to Spring 1998 had 16 well-defined and 18 marginal cases
  • Length of events ranges up to 58 hours
  • Events have a tendency to be nocturnal
  • Large lake-land temperature difference focuses precipitation bands
  • GSLE cases tend to have little low level directional wind shear
  • Lake-700 hPa temperature difference always greater than dry adiabatic
  • Precipitation structures observed:
    • Mid-lake bands
    • Broad area coverage (multiple bands not observed)
  
  
  

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