Interannual prediction of the Parana river

Interannual-to-decadal predictability of the Parana. river in South America is investigated by extracting near-cyclic components in summer-season stre amflows at Corrientes over the period 1904-1997. It is found that oscillato ry components with periods of about 2-5, 8 and 17 years are accompanied by statistically significant changes in monthly streamflow. Autoregressive pre dictive models are constructed for each component. Cross-validated categori cal hindcasts based on the 8-yr predicted component are found to yield some skill up to four years in advance for below-average flows. A prediction ba sed upon the 8- and 17-yr components including data up to 1999 suggests inc reased probability of below-average flows until 2006.