How will Climate Change Affect Weather Patterns in the Great Lakes Region? Peter J. Sousounis Geography Department Michigan State University, East Lansing, MI

Background Information Greenhouse gases make our planet habitable Too much of a good thing can be bad GCMs are our climatological crystal ball Recent motivation

Climate Scenarios - Temperature Both GCMs (General Circulation Models) indicate a warmer future by the end of the century Canadian Model is considerably warmer than Hadley Model Canadian Model 21st Hadley Model 21st +15.F +10.F +5.F F +15.F +10.F +5.F F

Both GCMs (General Circulation Models) indicate increased precipitation Canadian Model drier than Hadley in Eastern US regions & wetter in Southwestern US and mountainous regions Canadian Model 21st Hadley Model 21st 100% 80% 60% 40% 20% 0 -20% -40% -60% -80% - 100% Climate Scenarios - Precipitation

CANADIANHADLEY Monthly Thickness - Future Conditions Thickness of the lower half of the atmosphere reflects surface temperature in a large scale way. A thicker atmosphere is a warmer atmosphere. Canadian Model shows significant increases in thickness throughout the year by the end of the century Hadley Model shows overall smaller changes than Canadian Model Both Models show greater increases in fall & winter, than spring & summer

Arctic Blasts - Current Scenario Current arctic air outbreaks cause daytime temps to be in the single digits and teens as far south as Kentucky. 0s-10 s 20s-30 s

Arctic Blasts - Future Scenario Such air masses will likely be confined to Canada by the end of this century. 0s-10 s 20s-30 s

Monthly Precipitation - Future Conditions Canadian shows an increase of ~8% in annual precipitation by Most of the increase occurs during January-June Hadley shows an increase of 12%. Most of the increase occurs during July-December CANADIAN HADLEY

Why Should Precipitation Increase…? More frequent storms Slower storms Stronger storms Moister storms More efficient storms

Heavy Precipitation DAYS for Detroit, Michigan Both models suggest an increase in interannual variability Canadian Model shows increases from 6 to 8 days Hadley Model increases from 3 to 6 days

Both models suggest an increase in interannual variability Canadian Model shows increases from 160 to 240 mm Hadley Model shows increases from 68 to 133 mm Heavy Precipitation AMOUNT for Detroit, Michigan

CURRENTFUTURE Precipitation - Hadley Extreme PCN Pattern The Hadley Model (above) shows a precipitation increase from 23 to 29 mm. The heavier precipitation in both models will likely result from slightly more intense lows and sharper warm fronts. Both models show similar patterns for the current and future climate scenarios but with lows farther to the southwest. The Canadian Model shows increases from 40 to 47 mm…

Both models show a decrease in cyclones and a reduction in associated windspeed. The Canadian Model shows a big decrease in cyclones from late spring/ mid summer and from late fall/ mid winter. The Hadley Model shows a big decrease in cyclones in winter and a bigger decrease in spring. CANADIAN HADLEY Monthly Storms - Future Climate

80 inches Snow Depth - Historic, Hadley & Canadian

80 inches 46 inches Snow Depth - Historic, Hadley & Canadian

80 inches 46 inches 10 inches Snow Depth - Historic, Hadley & Canadian

Historic Record: Hadley Model: Canadian Model: = >1” Snow Day # Snow Days - Historic, Hadley & Canadian

Historic Record: Hadley Model: Canadian Model: = >1” Snow Day # Snow Days - Historic, Hadley & Canadian

Historic Record: Hadley Model: Canadian Model: = >1” Snow Day # Snow Days - Historic, Hadley & Canadian

Unfortunately, while it may become too warm for snow, it will still be too cold for people to switch to other (typically summertime) recreational activities such as camping, golfing, and bicycling. More people may find themselves stuck at home and there may be more incidences of Seasonal Affective Disorder - a SAD state of affairs indeed. Peter Sousounis - The Future of Lake-Effect Snow: A SAD Story, Jan-Feb Acclimations: A SAD Story…

Future Winter Flow Patterns… Both models suggest more frequent and intense El Ninos - especially the Hadley Model…

Summary Climate change in the Great Lakes region will be manifested by changes in winds and storm tracks as well as by changes in temperature and precipitation. Extreme hot days will occur at least twice as frequently, extreme precipitation events will increase in frequency and intensity. The number of cyclones will decrease by ~15% and windspeeds will decrease by 10%. Interannual variability will also likely increase. The magnitudes of the climate changes will likely have significant impacts on ecosystems in the region.