An objective method for forecasting five-day rainfall over Delhi during July and August

The present study is an attempt to evolve a technique for forecasting pentad rainfall over Delhi for the month of July and August. Composite charts for conditions antecedent to excessive and deficient rainfall, during the pentad under consideration, are prepared. The contrasting features of the circulation patterns revealed in these composite charts are taken as guides to picking up crucial station pairs whose relative heights could be taken as representative of the contrasting features. From dot diagrams of rainfall character (as A,' N and S) and pairs of pressure-height co-ordinates the relationship between the predictor and predictant are worked out on the basis of contingency technique. The forecast scheme gives a skill score of. 55.