The northeastern part of Brazil (in particular the state of Ceará) is semiarid, has a rainy season from February to April, and is subject to wide rainfall fluctuations from year to year. Throughout Brazilian history, especially dry periods have been marked by severe social dislocations and mass migrations which have affected the 30 million people of Ceará and the entire social and economic fabric of Brazilian culture.
Statistical correlations of rainfall with climatic indices [ Hastenrath, 1990] have indicated that such rainfall is correlated with SST in both the Atlantic and the eastern Pacific. Realizing the vulnerability of its economy to such interannual climate fluctuations, the state of Ceará, in conjunction with the federal government, set up an institute, FUNCEME (Fundadação Cearense de Meteorologia e Recursos Hidricos), to advise the state on the proper actions to take in anticipation of adverse climatic conditions. FUNCEME has published a monthly information bulletin (Monitor Climático) since 1987 which gives monthly global climatic data, ENSO predictions, and specifically local precipitation and hydrological data.
FUNCEME maintains programs that address both long and short term issues. On the long term, it advises about actions to be taken on water resources and distribution, well recovery, crop choices and distribution, soil conditions, and environmental degradation. On the short term, it issues forecasts for the rainy season and explicit instructions to the various regions of Ceará about the timing of planting and about which crops to emphasize, depending on the forecast of abundant or deficient rainfall.
As a result of these actions, the agricultural output of Ceará has shown a
gradual leveling effect, no longer subject to the drastic ups and downs of
interannual climatic variability [ Moura, 1994]. For example, the normal grain
output for normal rainfall years in Ceará is 650,000 metric tons. In 1987,
before concerted action policies were in place, the response to a poor
rainfall year (30% below normal) was a grain production for that year of
100,000 metric tons, which led to severe hardship in Ceará and the
necessity of central governmental relief. In 1992, however, the rainfall
was equally poor (27% below normal) but a set of concerted actions in
response to a relatively accurate forecast allowed the grain production to
be 530,000 tons. Even with a second consecutive poor rainfall year (again
relatively accurately forecast) the grain production was 250,000
tons.