Bias-free rainfall forecast and temperature trend-based temperature forecast using T-170 model output during the monsoon season

Abstract

An objective forecasting system for medium-range location-specific forecasting of surface weather elements has been evolved at the National Centre for Medium Range Weather Forecasting, India (NCMRWF). The basic information used for this is the output from the T-170 general circulation model (GCM). The direct model output (DMO) forecast is briefly explained along with the T-170 model. The two important weather parameters considered in detail are rainfall and temperature. Both the parameters have biases. Techniques used for obtaining bias-free rainfall forecasts and temperature trend-based forecasts are explained in detail. These forecasts are obtained for all of the 602 districts of India. Finally, an evaluation of the accuracy of rainfall and temperature forecasts for selected districts for which the observed data could be obtained during the 2006 monsoon is presented. Copyright © 2007 Royal Meteorological Society.