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During the Arabian Sea Monsoon Experiment (ARMEX) period India Meteorological Department (IMD) forecast products along with other products are utilised for day-to-day monitoring and providing the guidance to the field scientists engaged in the collection of meteorological and oceanographic data. In the present study, the operational analysis and forecast products of limited area forecast system for some of the major synoptic systems that occurred during the ARMEX period was investigated. Further, using the additional data available from ARMEX Phase-II namely SYNOP, upper air and also satellite data, the impact of these data in the IMD's operational limited area forecast system during the onset phase of monsoon 2003 has been investigated. Verification of analysis and forecast fields with this additional data has shown substantial improvement in the analysis and model predicted rainfall.

A simple method for daily rainfall analysis at the resolution of 1° × 1° Lat./Long. over Indian monsoon region is applied from the use of dense land observations and satellite rainfall estimates for the month of June 2001.  The results obtained show that the analysis is able to capture large scale as well as mesoscale features of monsoon precipitation system. The availability of this data is expected to be very useful for the synoptic meteorologists and numerical weather prediction modelling community.

An attempt has been made to identify the main synoptic features, which are responsible for onset of southwest monsoon over the two met sub divisions east and west Rajasthan for the period 1971-2004 based on modern observational technology and developed forecasting technique in the field of short-range prediction of monsoon surges. The low pressure systems (LPS) originate over Arabian Sea, especially the formation of MTC which indicates a good signature for predicting onset of monsoon, which is the prominent feature for causing onset of summer monsoon over Rajasthan. In addition LPSs form over Bay of Bengal moved in west to northwestwards direction and reach over Rajasthan and its neighbourhood region as a lopar or an upper air cycir, also brings monsoon over Rajasthan.