There is some good news awaiting the new Government. This years monsoon is not only scheduled to arrive on time but also expected to result in good rains,at least in the first half of the four-month rainy season in the Indian Subcontinent. The latest analysis of weather patterns suggests that the onset of monsoon over the Andaman and Nicobar Islands might take place around May 20. The Indian Meteorological Department on Thursday said it was expecting monsoon over Kerala on May 26. Based on medium range predictions for the next week,a gradual build-up of monsoon flow over South-east Bay of Bengal and around the Andaman islands is likely to begin from May 18. This flow is expected to strengthen further and result in greater moisture incursion into the region in the next 2-3 days. Weather scientists are also predicting a gradual rise in temperatures by 2-4 degrees in most parts of the country over the next week,starting from Rajasthan and spreading to north and central India. The rise is likely to happen in both day and night temperatures. This is a positive signal for a good build-up of monsoon,which requires continuous and long-term heating of the land surface,a weather scientist said. Another favourable indicator is what is known as the Madden Julian Oscillation (MJO),a wind anomaly in the equatorial region,which helps in triggering the onset of monsoon. Many weather agencies,including the Climate Prediction Centre in the US,are forecasting enhanced convection and increased rainfall activity over the equatorial north Indian Ocean beginning from the second week of May. What is interesting is that this phenomenon,which generally holds for 4-5 days,is likely to stagnate over the area at least till the end of this month. This is a very conducive situation for widespread rainfall activity over the Andaman Sea and South-east Bay of Bengal, Akhilesh Gupta,a weather scientist,said. This years monsoon is likely to remain largely unaffected by El-Nino/La-Nina conditions. Weather agencies like International Research Institute for Climate and Weather in the US and Japan Agency for Marine Earth Science and Technology (JAMSTEC) are predicting that the current weak La-Nina condition over the Pacific would turn neutral and even become weak El-Nino conditions at the end of the year. As of now,the only concern seems to be the Indian Ocean Dipole (IOD) which is showing signs of becoming negative in a few weeks. A positive IOD is indicative of good rainfall activity over the Indian subcontinent while negative IOD suggests a deficit in rainfall. According to estimates by JAMSTEC,the IOD was likely to turn slightly negative in the second half of the monsoon season,which might adversely affect the rainfall in the country. Scientists are keeping a close watch on this and a clearer picture is likely to emerge by the time the Indian Meteorological Department comes up with its revised forecast in June.
