India, Dec. 18 -- The Government of India has issued a release:
The IMD's seasonal forecast for the 2024 & 2025 southwest monsoon seasons proved to be highly accurate. The details of IMD seasonal forecast verification for All India Summer Monsoon Rainfall for the period 2024 & 2025 is given below:
All India Summer Monsoon Rainfall Forecast Verification
Second Stage Forecast (%)
2024
108
106
106
Above Normal
Accurate
2025
108
105
106
Above Normal
Accurate
*Model error ± 5% of LPA for 1st stage
The spatial probability forecasts during both years had also indicated, highlighted above-normal rainfall across the country, except in Northeast India. Overall, the forecast aligned well with observed rainfall patterns across much of India, with only a few deviations noted in parts of the Gangetic Plains.
Parameter/System
2013-2014
2024-2025
Automatic Weather Station network
675
1008
Doppler Weather Radar
15
47
Rain Gauge Stations
3500
6700
Runway Visual Range Systems
20
180
Current weather indicating systems
29 Airports
117 airports with 137 Systems
Pressure measuring
Mercury
Digital Barometers
High Performance Computing (HPC)
1.1 Peta flops Processing speed
28 Peta flops Processing speed
Upper air observations
43 RS/RW Stations
56 RS/RW Stations. 62 Pilot Balloon stations
High Wind Speed Recorders
19
37 (By 2024)
Actual (%)
First Forecast (%)
Rainfall Category
Remark
**Model error ± 4% of LPA for 2nd stage
Monsoon rains are critical for the agricultural sector, particularly over the monsoon core zone, consisting of most of the rainfed agriculture areas in the country. However, over most areas of the monsoon core zone received normal to above normal rainfall during both years. In 2024, annual crop production in the country was above normal, and during 2025, the annual crop production is expected to be above normal.
Barometers
62 Pilot Balloon stations
Year
IMD is continuously working on upgrading and improving its seasonal prediction systems through advances in empirical, dynamical, and multi-model ensemble-based approaches. Ongoing enhancements focus on refining model physics, improving data assimilation, increasing model resolution, integrating more robust ensemble techniques, and using AI/ML to deliver more accurate and reliable seasonal forecasts.
For the 2024 southwest monsoon season, the first stage forecast for the season (June- September) rainfall over the country as a whole issued in April was 106% of LPA with a model error of ± 5% of LPA, and the update forecast issued in the end of May 2024 was 106% of LPA with a model error of ± 4% of LPA. The actual season rainfall for the country as a whole was 108 % of LPA. Thus, the seasonal rainfall forecast for the country as a whole was correct. Considering the four broad geographical regions of India, the forecasts issued on 27th May 2024 indicated that the southwest monsoon seasonal (June to September 2024) rainfall is most likely to be above-normal over Central India and South Peninsular India (>106% of LPA), normal over Northwest India (92-108% of LPA) and below normal over Northeast India (106% of LPA.
Various steps have been taken by the Government to strengthen IMD's data network, and there has been tremendous progress in modernising IMD's observational system with the installation of new Doppler Weather Radars (DWR), lightning alert systems, and automated weather stations across the country. The details of progress till 2024- 2025 compared to 2013-2014 (last 10 years) for India, are enclosed in Annexure-1. Currently, 47 radars are in operation across India, with 87% of the country's total area under radar coverage. In the coming years, additional DWRs will be installed as per the requirement so as to bring the entire country under the radar coverage.
The actual rainfall over Northwest India, Central India, Northeast India, South Peninsula, and Monsoon Core Zone was recorded at 107%, 120%, 86%, 114% and 119% of the LPA, respectively. The seasonal forecast issued for homogeneous regions during the season was within the range of the forecast for all four regions.
Disclaimer: Curated by HT Syndication.
