10.2190/LD4Q-LQ5K-EV90-5WP9 LD4QLQ5KEV905WP9 4 Performance Evaluation of Medium-Range Weather Forecast Using Crop Growth Simulator 397 408 20020509 20020509 20020509 20020509 LD4QLQ5KEV905WP9.pdf http://baywood.metapress.com/link.asp?target=contribution&id=LD4QLQ5KEV905WP9 4 K. K. Singh Naveen Kalra U. C. Mohanty L. S. Rathore National Centre for Medium Range Weather Forecasting, Mausam Bhavan, New Delhi Indian Agricultural Research Institute, New Delhi Medium range forecast, a recently introduced service in India, has not been evaluated satisfactorily in terms of agricultural applications. In this article an attempt has been made to evaluate the performance of medium range weather forecast for Delhi and Ludhiana environment in the rabi (winter) season of 1994-95 by comparing the forecasted with actual weather components, mainly maximum and minimum temperature, wind speed, sunshine hours, and rainfall. Furthermore, yield and growth response of wheat simulated under adequate, moderate, and limited irrigated conditions were compared for forecasted and actual weathers employing wheat growth simulator (WTGROWS). Medium-range forecast performance for predicting maximum and minimum temperatures for both the locations had predictability lying in the range of 70 to 85 percent. the precision was somewhat better in case of maximum temperature assessment. Wind speed for both locations was poorly assessed. Forecasted rainfall matched actual rainfall on some occasions only at Ludhiana but the performance, in terms of seventy-two hours around the forecasted time, gave better results. the observed bright sunshine hours showed poor predictability (less than 30%). Forecasted grain yields for all levels of soil moisture availability treatments at both the locations were higher by about 2 to 9 percent when compared with the corresponding values obtained under actual weather runs. A similar trend was noticed for above ground biomass but the degree of variation was lower. Seasonal evapotranspiration and transpiration values showed correspondence with the rains received during the crop growing period. P. K. Aggarwal, N. Kalra, A. K. Singh, and S. K. Sinha, Analyzing the Limitations Set by Climatic Factors, Genotype, Water and Nitrogen Availability on Productivity of Wheat. I. <i>the Model Description, Parametrization and Validation, Field Crops Research, 38</i>, pp. 73-91, 1994. National Meteorological Centre, <i>Research Version of Medium Range Weather Forecast Model, Vol. 1</i>, 1988. National Centre for Medium Range Weather Forecasting, <i>The Performance of NCMRWF Operational Forecast System during Monsoon-1994.</i> P. K. Aggarwal and N. Kalra, Analyzing the Limitations Set by Climatic Factors, Genotype, Water and Nitrogen Availability on Productivity of Wheat. II. Climatically Potential Yields and Optimal Management Strategies, <i>Field Crops Research, 38</i>, pp. 93-103, 1994. P. K. Aggarwal and N. Kalra (eds.), <i>Simulating the Effect of Climatic Factors, Genotype and Management on Productivity of Wheat in India</i>, IARI Publication, New Delhi, India, 156 pp., 1994.