IMD Improves Winter Forecasts with Better Weather Models

The India Meteorological Department (IMD) continues to issue seasonal temperature outlooks for the winter months of December to February, using coupled dynamical models. Since 2023, these forecasts have been generated through the Multi-Model Ensemble (MME) technique, providing probabilistic outlooks for maximum and minimum temperatures along with anomaly forecasts for the number of cold wave days. IMD also issues monthly temperature outlooks, including cold wave information, during the winter season.

Spatial probabilistic forecasts are provided at the meteorological subdivision level and are shared through IMD press releases, briefings, and social media updates. In addition to seasonal and monthly outlooks, IMD issues weekly cold wave alerts every Thursday, valid for the following four weeks. These forecasts are available on the IMD website and are disseminated to States through meteorological and regional meteorological centres.

International Outlooks Complement IMD Guidance

Several international agencies including ECMWF, NOAA CPC, and the UK Met Office also release global and regional temperature forecasts using climate models. These maps include the South Asian region, but they are not specifically designed for India. IMD remains the official agency issuing seasonal guidance for the country through its Cold Weather Season Temperature Outlook, prepared using bias-corrected minimum temperature fields from climate models.

Improved Forecast Skill Through MME System

IMD regularly verifies its winter forecasts, and the introduction of the MME scheme has led to improved skill in recent years. Spatial verification plots available on the IMD Pune website indicate better performance compared to earlier forecast cycles. Links for verification of seasonal and monthly maximum and minimum temperature forecasts are provided in Annexure-1.

The department has adopted an enhanced methodology for daily, weekly, monthly, and seasonal forecasts using MME systems. This includes the Monsoon Mission Climate Forecasting System (MMCFS), tools that provide weekly forecasts up to four weeks and models that give short- and medium-range forecasts up to seven days. IMD has also started using the Bharat Forecasting System, which is currently the highest-resolution operational weather model globally, with a spatial resolution of 6 km. Verification from recent seasons shows improved accuracy compared to single-model forecasts.

Strengthened Monitoring and Data Systems

IMD continues to keep track of weather and climate conditions across India and publishes reports such as the Annual Climate Summary and State-wise Climate Statements. Climate data from 1901 onward has been digitized and is available through an online portal. IMD also shared this data with research and development organisations to support improved understanding and prediction.

Recently, IMD launched Mission Mausam, aimed to strengthen weather and climate services across the country including better monitoring, improved prediction, and enhanced understanding of weather and climate in India.