Climate seasonal forecast and derived indexes for droughts in Ceará, Brazil

Previous studies have shown the good relationship between climate variability and maize yield in Ceará (e.g. Rao et al. 1997), although large biases have been found. Sun et al. (2005) demonstrated that some features of the intraseasonal variability (e.g. dry and wet spells) can be reproduced by using Global-to-Regional nested grid climate model forced by prescribed SST. Using climate indexes, Sun et al. (2007) show the potential predictability of maize yield in “Sertão Central” region in Ceará. However, it is still left to demonstrate the ability of the prediction system in forecasting such indexes.