Weather conditions over southern Ontario on the night of November 18, 2010 during the crash of a small aircraft

Weather conditions downstream of large lakes during the cool season present unique hazards to small aircraft at low levels, particularly at night and specifically during the months of November-December when the Great Lakes retain some warmth. Hazards that may be encountered by pilots flying at heights of several thousand feet AGL downwind of the Great Lakes include sudden reductions in visibility due to cloud and precipitation in otherwise clear sky, as well as icing of aircraft surfaces. The weather conditions present during the evening of November 18, 2010 in southern Ontario at the time of the crash of a Beechcraft Bonanza F-33A single-engine small aircraft southeast of Lake Huron's Georgian Bay were a good example of these conditions. Details of the flight leading up to the fatal crash are available in the Canadian Transportation Safety Board Report # A10O0240 (online at http://www.tsb.gc.ca/eng/rapports-reports/aviation/2010/a10o0240/a10o0240.asp). In this poster, the low-level winds, air and lake surface temperatures, stability and humidity content of the air in the region southeast of Georgian Bay have been analyzed to illustrate weather hazards that may develop for low-flying aircraft in regions downwind from the Great Lakes during cool autumn nights.