Extended winter Pacific North America oscillation as a precursor of the Indian summer monsoon rainfall
Article first published online: 13 JUN 2009
Copyright 2009 by the American Geophysical Union.
Geophysical Research Letters
Volume 36, Issue 11, June 2009
How to Cite
2009), Extended winter Pacific North America oscillation as a precursor of the Indian summer monsoon rainfall, Geophys. Res. Lett., 36, L11710, doi:10.1029/2009GL038453., , and (
- Issue published online: 13 JUN 2009
- Article first published online: 13 JUN 2009
- Manuscript Accepted: 11 MAY 2009
- Manuscript Revised: 4 MAY 2009
- Manuscript Received: 1 APR 2009
- statistical seasonal forecasting;
- Indian summer monsoon;
- Pacific North America Oscillation
 In spite of considerable efforts, long-range forecasting of Indian summer monsoon rainfall (ISMR) is still a challenge for both statistical and dynamical tools. We highlight the winter-to-spring Pacific North America (PNA) oscillation as a predictor for the ISMR. A PNA-related index is proposed that is highly correlated with the following summer precipitation over India and is also a precursor of El Niño-Southern Oscillation (ENSO) events over recent decades. The PNA index compares well with other predictors used in operational statistical models for ISMR prediction. A multiple linear regression scheme is tested with a cross-validation hindcast approach and confirms the added value of our predictor, at least over the period 1958–2005. Nevertheless, the predictor shows less skill over the first half of the 20th century. Possible physical mechanisms of this teleconnection are also briefly discussed and could involve both a tropical Pacific sea surface temperature and Eurasian snow cover pathway.