Foreshadowing Northeast Monsoon Rainfall Over Tamil Nadu, India

Abstract

The association between the southwest and northeast monsoon (October-December) rainfall over Tamil Nadu has been examined for the 100-year period from 1877 to 1976. A correlation analysis between the two rainfall series revealed that the southwest monsoon (June-September) rainfall is negatively correlated with that of the northeast monsoon rainfall. That is, an excess or deficit of southwest monsoon rainfall over this region is generally followed by an opposite tendency in the northeast monsoon rainfall. A χ2 test of dependence further indicated that the rainfalls in the two monsoons are not independent of each other. The negative rainfall relationship can be a useful tool in foreshadowing the northeast monsoon rainfall over Tamil Nadu, which is of considerable economic importance for this region.