1. Climate variations in the Northwest, seasonal climate forecasting, and outlook for winter 2001-2002 Philip W. Mote Climate Impacts Group University of Washington

4. A history of the PDO warm cool warm A history of ENSO 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

9. Effects of PDO and ENSO on Idaho temperature Warm ENSO, warm PDO Warm ENSO Cool ENSO Cool ENSO, cool PDO ½½ ENSO neutral, cool PDO Degrees F Years classified according to http://www.atmos.washington.edu/~mantua/TABLES2.html

10. Effects of PDO and ENSO on Idaho precipitation Warm ENSO, warm PDO Warm ENSO Cool ENSO Cool ENSO, cool PDO ENSO neutral, cool PDO Years classified according to http://www.atmos.washington.edu/~mantua/TABLES2.html

11. Summary ENSO, PDO play a modest role in winter and spring climate: zwarm ENSO, warm PDO tilt balance to above- average temperatures and below-average precipitation zcool ENSO, cool PDO tilt balance (less) toward cool wet zENSO and PDO can “cancel” each other zJan-Jun sensitive period for temp, Nov-Mar sensitive period for precipitation

12. Nov 2000-Feb 2001 500mb height

13. Nov 2000-Feb 2001 temperature anomalies Degrees F

14. Nov 2000-Feb 2001 precipitation anomalies Standard deviations

15. 2000-2001 Idaho temperature Warm ENSO, warm PDO Cool ENSO, cool PDO ½½ Degrees F Years classified according to http://www.atmos.washington.edu/~mantua/TABLES2.html

16. 2000-2001 Idaho precipitation Warm ENSO, warm PDO Cool ENSO, cool PDO Years classified according to http://www.atmos.washington.edu/~mantua/TABLES2.html * 2001 water year

17. Monitoring El Niño ENSO Observing Network of 70 buoys

21. The European Center’s ENSO Forecast Forecast SSTs in the eastern equatorial Pacific, from the European Center for Medium Range Weather Forecasting (www.ecmwf.int)

23. ENSO outlook summary zENSO remains in a near-neutral state zLeading ENSO prediction models are calling for weak El Nino sometime zWe’ve heard this before…

24. The Pacific Decadal Oscillation

25. Global SST anomalies

26. Pacific Decadal Oscillation Update Since fall 1998, PDO index has consistently had negative values PDO Persistence has historically been a skillful forecast (correct ~75% of the time) odds favor “cool/negative PDO” for winter 2002 1970198019902000 0

27. NDJ FMA MJJ

30. The Pineapple Express and tropical rainfall: a potential NW link to the tropical Madden-Julian Oscillation

31. Conclusions zWeak El Niño possible early 2002? zCPC’s forecast (educated guesswork) for Idaho: normal winter, spring will be warmer zwhat about PDO? Cool/wet influence (ignored by CPC) zOcean situation similar to last year (but atmosphere ignored ocean last year)