Great Lakes Weather and Climate

1. Great Lakes Weather and Climate

2. Introduction • Standing in for a speaker from Environment Canada that was unable to attend at the last minute • Until yesterday knew almost nothing about weather and climate in the Great Lakes but have been learning fast!

3. Great Lakes Weather and Climate • Forecasting weather and projecting climate • The role of the oceans and Great Lakes • Great Lakes climate change

5. First a bit of history • Early ability to predict weather constrained by: • Limited understanding of fundamentals of atmospheric circulation • Low density of accurate and synoptic observations • Limited capacity to communicate, integrate and interpret observations

6. Time Line 1848 - Volunteer Weather Observers recruited through Smithsonian Institution 1849 - Smithsonian supplies weather instruments to telegraph companies and establishes weather observation network 1870 - President Grant signs bill establishing a national weather warning service within Army Signal Corps 1890 - Cooperative Weather Observer Network established 1891 – Weather service transferred to Department of Agriculture, becomes United States Weather Bureau 1898 – Weather Bureau begins hurricane warning network 1900 - ‘Issacs storm’ kills over 6,000, Weather Bureau establishes regional forecasting centers in response

8. World Weather Watch • Established by WMO in 1963 • Creation of a globally coordinated system of observations, data communications, data processing and forecasting

9. Satellite observations of the atmosphere TIROS GOES

10. Computing • Meteorology took early advantage of the revolution in computing to deliver routine operational products

12. Why are the oceans so important? Because, that is where most of the heat goes Data from Levitus et al, Science, 2001

14. Systematic observation of the global ocean became a goal in 1990 The Global Ocean Observing System A joint initiative of:

15. Technology • Comprehensive array of technologies for in-situ measurement

16. 57% 100% 40% 82% 100% 43% 72% 21% 48%

19. Operational Systems

22. 1000 to 1861, N. Hemisphere, proxy data • 1861 to 2007, Global, instrumental • 2007 to 2100, SRES projections

23. Evidence of Climate Change in the Great Lakes Region • Temperatures are rising, especially in winter. • Extreme rainfall events (24-hr and 7-day) are becoming more frequent. • Winters have become shorter. • Spring is coming earlier. • Duration of ice cover is shorter, especially on smaller lakes.

24. Deg F 16 15 14 13 12 11 10 9 8 7 6 Deg F 16 15 14 13 12 11 10 9 8 7 6 Projected Temperature Increase in the Great Lakes Region (by 2070-99) Summer Winter Lower emissions Higher emissions

25. Projected Precipitation Changes in the Great Lakes Region (by 2070-99) • Doubling of heavy precipitation events • Seasonal shifts in precipitation -- * More rain in winter and spring (planting season) * Less rain during the summer and fall growing seasons

26. Projected Climate Changes in the Great Lakes Region by 2100 • Temperature • Winter 5-12 °F (3-7 °C) • Summer 5-20 °F (3-11 °C) • Extreme heat more common • Growing season several weeks longer • Precipitation • Winter, spring increasing • Summer, fall decreasing • Drier soils, more droughts • More extreme events – storms, floods • Could be 50-100% more frequent than now • Ice cover decline will continue