# 12 step ahead prediction desired

I have a time series of data with columns labeled Months and Rows labeled Years. So, my data looks as:

1900    -5     8    8    6    15   ......
1901    -3     8    8    6    15   ......
1902    -12    4    8    6    15   ......
1903    -34    1    8    6    15   ......
1904    -5     8    8    6    15   ......


The above data is just dummy and for illustration purpose only. My matrix is for period 1900 to 1950 hence the matrix size is 1950x12. The data is for flow in a river and hence there would be some correlation between flows of consecutive months.

I would like to predict data for year 1951 based on data from 1900 to 1950. What algorithm is best suggested for this purpose.

I can use Kalman Filter kind of method but that gives me only 1 step ahead forecast. I need to predict flow for 12 months. So, a Fourier analysis can be of use here as well.

Any other ideas ?