A novel approach to predict the onset of South West Monsoon in Kerala

T.K. Ajitha, P. Anil Kumar


A univariate statistical approach for prediction of onset of South West monsoon along with a model based on Pre Monsoon Rainfall Peak (PMRP) has been demonstrated in this study using the dates of onset for 147 years from 1870 – 2016 published by IMD and daily climatic variables viz; rainfall, maximum temperature, minimum temperature, relative humidity, sunshine hours and wind velocity for a period from 1984 – 2016 for the region Vellanikkara (bounded by 100 31'; 76013'), Thrissur. The average date of onset was found to be June1with a S.D of 7 days. The occurrence of a PMRP was confirmed about 8 pentads before the onset of monsoon. A significant correlation coefficient of 0.59 between the dates of PMRP and onset dates has resulted in the formulation of a regression equation to predict onset dates with adequate degree of precision. Long term predictions with minimum possible errors have been realised using an emerging univariate statistical model. A non contiguous regression model by means of weighted least squares with heteroscedasticity correction has been applied to predict onset dates using its own significant auto correlated lags.


Kerala, Onset, PMRP, Prediction

Full Text:



Ananthakrishnan R and Soman M.K ,1988. The onset of the south west monsoon over Kerala 1901 – 1980, J. Climatol., vol.8,: 283-296.

Goswami, P and Gouda, K.C, 2010: Evaluation of a dynamical basis for advance forecasting of the date of onset of monsoon rainfall over India. Mon. Wea. Rev., 138, 3120–3141.

Joseph P.V, Sooraj K.P and Rajan C.K. 2003. Conditions leading to monsoon onset over Kerala and the associated .Hadley cell. Mausam. 54(1): 155–164.

Kumar, M.R.R, 2004. Forecasting of onset of south west monsoon over Kerala coast using satellite data. IEEE Geoscience and remote sensing letters, vol.1,No.4, p 265-267.

Kung E.C and Sharif T.A (1982). Long range forecasting of the Indian summer monsoon onset and rainfall with upper air parameters and sea – surface temperature. J Meteorol Soc. Japan 60: 672 – 682.

Sooraj K.P (2004). A Diagnostic and modeling study on the onset of summer monsoon over south Asia.Thesis submitted to the Cochin University of Science and Technology in partial fulfilment of the requirement for the Degree of Doctor of Philosophy in Atmospheric Sciences:262p


  • There are currently no refbacks.

A KAU publication [CODEN: JTAGEI; ISSN 0971-636X; eISSN 0973-5399]