Changing predictability of Indian monsoon rainfall anomalies?

  • Stefan Hastenrath
  • Lawrence Greischar


The predictability of Indian summer monsoon rainfall from pre-season circulation indices is explored from observations during 1939–91. The predictand is the all-India average of June–September precipitation NIR, and the precursors examined are the latitude position of the 500 mb ridge along 75°E in April (L), the pressure tendency April minus January at Darwin (DPT), March-April-May temperature at six stations in west central India (T6), the sea surface temperature (SST) anomaly in the northeastern Arabian Sea in May (ASM), SST anomaly in the Arabian Sea in January (ANJ), northern hemisphere temperature anomaly in January–February (NHT), and Eurasian snow cover in January (SNOW). Monsoon rainfall tends to be enhanced with a more northerly ridge position, small Darwin pressure tendency, warmer pre-season conditions, and reduced winter snow cover. However, relationships have varied considerably over the past half-century, with the strongest associations during 1950–80, and a drastic weakening in the 1980s.

Four prediction models were constructed based on stepwise multiple regression, using as predictors combinations of L, DPT, T6, ASM, and NHT, with 1939–68 as “dependent” dataset, or training period, and 1969–91 as “independent” dataset or verification period. For the 1969–80 portion of the verification period calculated and observed NIR values agreed closely, with the models explaining 74–79% of the variance. By contrast, after 1980 predictions deteriorated drastically, with the explained variance for the 1969–89 time span dropping to 25–31%. The monsoon rainfall of 1990 and 1991 turned out to be again highly predictable from models based on stepwise multiple regression and linear discriminant analysis and using as input L + DPT or L + DPT + NHT, and with this encouragement an experimental real-time forecast was issued of the 1992 monsoon rainfall.

These results underline the need for investigations into decadal-scale changes in the general circulation setting and raise concern for the continued success of seasonal forecasting.


Climate prediction monsoon climatic change 


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  1. Afifi A A and Azen S P 1979Statistical analysis: A computer oriented approach (p. 302–309) (New York:Academic Press) pp. 442Google Scholar
  2. Banerjee A K, Sen P N and Raman C V R 1978 On foreshadowing southwest monsoon rainfall over India with mid-tropospheric circulation anomaly in April;Indian J. Meteorol., Hydrol. Geophys. 29 425–431Google Scholar
  3. Bhanu Kumar O S R U 1988a Interaction between Eurasian winter snow cover and location of the ridge at the 500 hpa level along 75°E;J. Meteorol. Soc. Jpn. 66 509–514Google Scholar
  4. Bhanu Kumar O S R U 1988b Eurasian snow cover and seasonal forecast of Indian summer monsoon rainfall;J. Hydrol. Sci. 35(5) 515–525Google Scholar
  5. Bottomley M, Folland C F, Hsiung J, Newell R E and Parker D E 1990Global ocean surface temperature atlas; Meteorological Office, Bracknell, UK, pp. 313Google Scholar
  6. Climate Analysis Center, NOAA 1992;Climate diagnostics bulletin, January to June 1992; NOAA, Washington D CGoogle Scholar
  7. Das P K 1986Monsoons (p. 126–136) Fifth IMO Lecture, World Meteorological Organization, WMO-No. 613, Geneva, Switzerland, pp. 155Google Scholar
  8. Draper N R and Smith H 1981Applied regression analysis (307–311). (Wiley) pp. 709Google Scholar
  9. Elliott W P and Angell J K 1987 The relation between Indian monsoon rainfall, the Southern Oscillation, and hemispheric air and sea temperature: 1884–1984;J. Climate Appl. Meteorol. 26 943–948CrossRefGoogle Scholar
  10. Elliott W P and Angell J K 1988 Evidence for changes in Southern Oscillation relationships during the last 100 years;J. Climate 1 729–737CrossRefGoogle Scholar
  11. Fu C and Fletcher J 1988 Large signals of climatic variations over the ocean in the Asian monsoon region;Adv. Atmos. Sci. 5 389–404CrossRefGoogle Scholar
  12. Gowariker V, Thapliyal V, Sarker R P, Mandai G S and Sikka D R 1989 Parametric and power regression models: New approach to long range forecasting of monsoon rainfall in India;Mausam 40 115–122Google Scholar
  13. Hastenrath S 1987 On the prediction of Indian monsoon rainfall anomalies;J. Climate Appl. Meteorol. 26 847–857CrossRefGoogle Scholar
  14. Hastenrath S 1988 Prediction of Indian monsoon rainfall: Further exploration;J. Climate 1 298–304CrossRefGoogle Scholar
  15. Hastenrath S 1990 Tropical climate prediction: A progress report 1985–90;Bull. Am. Meteorol. Soc. 71 819–825CrossRefGoogle Scholar
  16. Hastenrath S 1991Climate dynamics of the tropics (p. 347–373); (Kluwer, Dordrecht, Boston, London) pp. 488Google Scholar
  17. Hastenrath S and Greischar L 1983 Further work on the prediction of northeast Brazil rainfall anomalies;J. Climate 6 (in press)Google Scholar
  18. Jones P D, Raper S C B, Bradley R S, Diaz H F, Kelly P M and Wigley T M L 1986 Northern hemisphere surface air temperature variations: 1851–1984;J. Climate Appl. Meteorol. 25 161–178CrossRefGoogle Scholar
  19. Mooley D A and Parthasarathy B 1984 Fluctuations in all India summer monsoon rainfall during 1871–1978;Climatic Change 6 287–301CrossRefGoogle Scholar
  20. Parthasarathy B, Rupa Kumar K, Kothawate D R 1992 Indian summer monsoon rainfall indices 1871–1990.Meteorol. Mag. 121 174–186Google Scholar
  21. Parthasarathy B, Diaz F and Eischeid J K 1988 Prediction of all India summer monsoon rainfall with regional and large-scale parameters;J. Geophys. Res. 93 5341–5350CrossRefGoogle Scholar
  22. Parthasarathy B, Rupa Kumar K and Sontakke H A 1990 Surface and upper air temperatures over India in relation to monsoon rainfall;Theor. Appl. Climatol. 42 93–110CrossRefGoogle Scholar
  23. Prasad K D and Singh S V 1992 Possibility of predicting Indian monsoon rainfall on reduced spatial and temporal scales;J. Climate (submitted)Google Scholar
  24. Quenouille M A 1952Associated measurements (p. 168). (Butterworths) pp. 242Google Scholar
  25. Shukla J and Mooley D A 1987 Empirical prediction of the summer monsoon rainfall over India;Mon. Weather Rev. 115 695–703CrossRefGoogle Scholar
  26. Thapliyal V 1982 Stochastic dynamic model for long-range prediction of monsoon rainfall in peninsular India;Mausam 33 399–404Google Scholar
  27. Thapliyal V 1990 Long-range prediction of summer monsoon rainfall over India: Evolution and development of new models;Mausam 41 339–346Google Scholar
  28. Verma R K, Subramaniam K and Dugam S S 1985 Inter-annual and long-term variability of the summer monsoon rainfall and its possible link with northern hemispheric surface air temperature;Proc. Indian Acad. Sci. (Earth Planet. Sci.) 94 187–198Google Scholar
  29. Wilkinson L 1989SYSTAT, the system for statistics (p. 116–178) SYSTAT Inc., Evanston, IL, pp. 638Google Scholar
  30. Woodruff S D, Stutz R J, Jenne R L and Steurer P M 1987 A comprehensive ocean-atmosphere data set;Bull. Am. Meteorol. Soc. 68 1239–1250CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 1993

Authors and Affiliations

  • Stefan Hastenrath
    • 1
  • Lawrence Greischar
    • 1
  1. 1.Department of MeteorologyUniversity of WisconsinMadisonUSA

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