1. Isle Royale Localization

2. Surface Air Temperatures Winter temperatures are less severe when waters are open due to relatively warm surface waters Island temperatures are generally cooler (warmer) than the mainland in summer (winter) Comparison of average highs for Isle Royale (red) and Kelliher, MN (blue) Source: http://www.weather.com/weather/wxclimatolog y/monthly/graph/USMI0431 http://www.weather.com/weather/wxclimatolog y/monthly/graph/USMI0431 Source: http://www.epa.gov/greatlakes/atlas/images/big 03.gif Comparison of average lows for Isle Royale (red) Kelliher, MN (blue) Source: http://www.weather.com/weather/wxclimatology/monthly/gr aph/USMI0431 http://www.weather.com/weather/wxclimatology/monthly/gr aph/USMI0431 Isle Royale Kelliher, MN

3. Precipitation Comparison of average precipitation for Isle Royale (red) and Kelliher, MN (blue) Source: http://www.weather.com/weather/wxclimatology/mo nthly/graph/USMI0431 http://www.weather.com/weather/wxclimatology/mo nthly/graph/USMI0431 The island generally receives less (more) precipitation during summer (winter) than the mainland Source:http://www.wunderground.co m/blog/weatherhistorian/article.html? entrynum=8 Isle Royale Kelliher, MN

4. Lake Ice Formation Warming surface water temperatures Surface winds modify ice location, form, and distribution Warming surface air temperatures (winter and/or summer) Increased mixing of water layers brings relatively warm deep waters (during winter) to the surface Increased wind and wave action Amount of ice cover from previous season - less (more) allows longer (shorter) period of absorbing solar radiation Source: http://www.epa.gov/greatlakes/atlas/images/big03.gif

5. Extreme Events The most extreme events have occurred in November when the weather transitions from fall to winter Source: http://www.wunderground.com/blog/w eatherhistorian/comment.html?entrynu m=5 November 9-12 has had: 1) the deadliest late-season tornado outbreak in the north- central United States, 2) deadliest Great Lakes storm, 3) most intense frontal passage in United States history, 4) deadliest blizzard in Minnesota history, and 5) the 2nd most intense low pressure system on record for the Midwest (only surpassed by the event of October 2010). Source: http://www.wunderground.com/blog/weatherhistorian/com ment.html?entrynum=5 Events are accompanied by drastic changes in air temperatures and/or intense amounts of precipitation falling