1. Changes in NAO and ENSO 3.4 and Their Effects on U.S. Climate by Elise Lancaster METEO 497A April 22, 2003

2. Introduction Introduction Methodology Methodology Results Results Other Research Possibilities Other Research Possibilities Conclusion Conclusion Outline

3. Introduction “The Idea” Find the largest 2-3 month differences in NAO and ENSO 3.4 Find the largest 2-3 month differences in NAO and ENSO 3.4 Note temperature and precipitation patterns of the month after the change Note temperature and precipitation patterns of the month after the change

4. Methodology Analyze NAO and ENSO 3.4 monthly values Analyze NAO and ENSO 3.4 monthly values Time Period: Nov - Apr (1950-present) Time Period: Nov - Apr (1950-present) Data Data NAO ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/tele_index.nh http://www.cpc.ncep.noaa.gov/data/teledoc/nao.html NAO ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/tele_index.nh http://www.cpc.ncep.noaa.gov/data/teledoc/nao.html ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/tele_index.nh http://www.cpc.ncep.noaa.gov/data/teledoc/nao.html ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/tele_index.nh http://www.cpc.ncep.noaa.gov/data/teledoc/nao.html ENSO ftp://ftp.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/sstoi.indices http://www.cpc.ncep.noaa.gov/data/indices/index.html ENSO ftp://ftp.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/sstoi.indices http://www.cpc.ncep.noaa.gov/data/indices/index.html ftp://ftp.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/sstoi.indices http://www.cpc.ncep.noaa.gov/data/indices/index.html ftp://ftp.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/sstoi.indices http://www.cpc.ncep.noaa.gov/data/indices/index.html

5. Methodology Calculate 2 and 3-month changes in values Calculate 2 and 3-month changes in values Examples Examples 2-month: Dec – Nov, Apr – Mar 2-month: Dec – Nov, Apr – Mar 3-month: Jan – Nov, Apr – Feb 3-month: Jan – Nov, Apr – Feb Determine largest changes/differences – use the most common month Determine largest changes/differences – use the most common month

6. Methodology Plot composites of the next month’s temperature and precipitation (http://www.cdc.noaa.gov/USclimate/USclimdivs.html) Plot composites of the next month’s temperature and precipitation (http://www.cdc.noaa.gov/USclimate/USclimdivs.html)http://www.cdc.noaa.gov/USclimate/USclimdivs.html

7. Results Graphs of values Graphs of values Composite U.S. temperature and precipitation maps Composite U.S. temperature and precipitation maps Observations of the composites Observations of the composites

9. Largest NAO 2-month Negative (–) Changes Month and Year ValueDifference December 1978 -2.5-5.2 March 1962 -3.7-4.6 March 1951 -2.5-3.7 March 1981 -1.8-3.3 April 1997 -2.2-3.3 March 1970 -1.7-3.0 March 2001 -1.8-2.9

10. NAO 2-month – Changes Temperature Warmer in eastern two-thirds of U.S. Warmer in eastern two-thirds of U.S. Cooler in Northwest Cooler in Northwest

11. NAO 2-month – Changes Precipitation Dry in Southeast, lower Midwest, Rockies, and CA/OR Dry in Southeast, lower Midwest, Rockies, and CA/OR Wet in Great Lakes (especially MN/WI) and Ohio Valley Wet in Great Lakes (especially MN/WI) and Ohio Valley

12. Largest NAO 2-month Positive (+) Changes Month and Year ValueDifference April 1952 1.73.9 April 1958 0.63.7 April 1962 1.24.9 December 1965 1.13.4 March 1986 2.33.3 April 1969 1.22.9 April 1981 0.92.7 April 2001 0.92.7

13. NAO 2-month + Changes Temperature Warmer over majority of U.S. Warmer over majority of U.S. Warmest in western states Warmest in western states Cooler in Northeast and on Gulf of Mexico coast Cooler in Northeast and on Gulf of Mexico coast

14. NAO 2-month + Changes Precipitation Dry in Northwest, CA, TX, OK, MO, AR, Great Lakes, Southeast, and Northeast Dry in Northwest, CA, TX, OK, MO, AR, Great Lakes, Southeast, and Northeast Wet in central Midwest, Southwest, and Ohio Valley Wet in central Midwest, Southwest, and Ohio Valley

16. Largest NAO 3-month Negative (–) Changes Month and Year ValueDifference March 1962 -3.7-4.7 April 1997 -2.2-3.8 March 1952 -2.2-3.7 January 1979 -0.8-3.5 March 1951 -2.5-3.1 March 1957 -1.8-3.0 March 2001 -1.8-2.5

17. NAO 3-month – Changes Temperature Warmer in Northeast, Northwest, Great Lakes, and Rockies Warmer in Northeast, Northwest, Great Lakes, and Rockies Cooler in Midwest and Gulf of Mexico coast Cooler in Midwest and Gulf of Mexico coast

18. NAO 3-month – Changes Precipitation Dry in Northwest, Southeast, upper Midwest, and New England Dry in Northwest, Southeast, upper Midwest, and New England Wet in Southwest, parts of Midwest, and PA region Wet in Southwest, parts of Midwest, and PA region

19. Largest NAO 3-month Positive (+) Changes Month and Year ValueDifference April 1964 1.73.1 January 1984 1.73.0 January 1986 1.63.0 February 1996 0.82.9 February 1997 1.62.8 February 1962 0.92.7 February 2002 1.62.6 February 1988 1.12.5 February 1990 0.72.5

20. NAO 3-month + Changes Temperature Warmer on east coast and western U.S. Warmer on east coast and western U.S. Cooler in Midwest Cooler in Midwest

21. NAO 3-month + Changes Precipitation Dry in Southwest and Northeast Dry in Southwest and Northeast Wet in Ohio River Valley and upper Midwest Wet in Ohio River Valley and upper Midwest

23. Largest ENSO 2-month Negative (–) Changes Month and Year ValueDifference April 1973 -0.15-0.83 January 1981 -0.40-0.83 April 1958 0.53-0.69 April 1978 -0.46-0.68 April 1983 1.22-0.67 April 1998 0.87-0.66

24. ENSO 2-month – Changes Temperature Warmer in Northwest, upper/lower Midwest, CA coast, and southern FL Warmer in Northwest, upper/lower Midwest, CA coast, and southern FL Cooler in Midatlantic, Ohio Valley, and Southeast Cooler in Midatlantic, Ohio Valley, and Southeast

25. ENSO 2-month – Changes Precipitation Dry in TX, FL, and upper Midwest Dry in TX, FL, and upper Midwest Wet in Northeast and Ohio River Valley Wet in Northeast and Ohio River Valley

26. Largest ENSO 2-month Positive (+) Changes Month and Year ValueDifference March 1950 -0.731.04 January 1953 0.510.99 February 1951 -0.070.97 February 1955 -0.420.97 February 1976 -1.080.77 February 1956 -0.510.68 February 1989 -1.360.62

27. ENSO 2-month + Changes Temperature Warmer in Southeast, NM, OK, and northern TX Warmer in Southeast, NM, OK, and northern TX Cooler in Northwest, upper Midwest, ME Cooler in Northwest, upper Midwest, ME

28. ENSO 2-month + Changes Precipitation Dry in Southwest, Rockies, and FL Dry in Southwest, Rockies, and FL Wet in Great Lakes, Ohio River Valley, OR, WA, MS, and AL Wet in Great Lakes, Ohio River Valley, OR, WA, MS, and AL

30. Largest ENSO 3-month Negative (–) Changes Month and Year ValueDifference April 1973 -0.15-1.44 April 1998 0.87-1.30 April 1983 1.22-1.22 March 1964 -0.18-1.09 April 1964 -0.62-1.07 April 1958 0.53-1.02

31. ENSO 3-month – Changes Temperature Warmer in Northwest, Midwest, and Northeast Warmer in Northwest, Midwest, and Northeast Cooler in Southeast, Midatlantic, and CA Cooler in Southeast, Midatlantic, and CA

32. ENSO 3-month – Changes Precipitation Dry in TX and surroundings, upper Midwest, and FL Dry in TX and surroundings, upper Midwest, and FL Wet in Ohio River Valley, Northeast, Great Lakes, and CA/OR Wet in Ohio River Valley, Northeast, Great Lakes, and CA/OR

33. Largest ENSO 3-month Positive (+) Changes Month and Year ValueDifference March 1976 -0.661.19 January 1956 -1.190.99 February 1956 -0.510.92 February 1953 0.390.87 February 1951 -0.070.86 February 1965 -0.280.81 February 1989 -1.360.78

34. ENSO 3-month + Changes Temperature Warmer in Southwest and FL Warmer in Southwest and FL Cooler in Northwest and upper Midwest Cooler in Northwest and upper Midwest

35. ENSO 3-month + Changes Precipitation Dry in Southwest, Rockies, and FL Dry in Southwest, Rockies, and FL Wet in MN, Great Lakes, and Midatlantic Wet in MN, Great Lakes, and Midatlantic

36. Other Research Possibilities Same process, but by month Same process, but by month See monthly trends, not just most extreme trends See monthly trends, not just most extreme trends Note similar trends between NAO and ENSO Note similar trends between NAO and ENSO

37. Conclusion Trends are evident in NAO and ENSO monthly “jumps” Trends are evident in NAO and ENSO monthly “jumps” Trends can be used in long range forecasting Trends can be used in long range forecasting