The precipitation in the Danube upper and middle basin is the main indicator for the Danube
discharge at the entry in the lower basin. Along with precipitation, from the category of
internal factors, in the first stage, we tried to find other predictors from the fields of
temperature, pressure and geopotential. In the second phase, we considered external
factors, taking into account the indices of solar/geomagnetic activity, represented by Wolf
numbers, 10.7 cm solar flux/aa geomagnetic index. In the Danube upper and middle basin …

Of the internal factors, we tested the predictors from the fields of precipitation, temperature,
pressure and geopotential at 500hPa. From the external factors, we considered the indices
of solar/geomagnetic activity. Our analysis was achieved separately for each season, for two
time periods 1901–2000 and 1948–2000. We applied developments in empirical orthogonal
functions (EOFs), cross correlations, power spectra, filters, composite maps. In analysis of
the correlative results, we took into account, the serial correlation of time series. For the …