Cycles in Victoria's annual rainfall

Charlie Nelson
January 2013

I have identified two multi-decadal cycles in Victoria's rainfall.  These sometimes reinforce each other and sometimes cancel each other.  Thus the individual cycles are tantalising but elusive.

Chart 1 overlays annual rainfall with the combined cycles.  Both are statistically significant.

Note the very small amplitude of the cycle before the early 1940’s followed by larger amplitudes since, as the cycles started reinforcing each other.

In Chart 2, I have extended the cycle to 2050 with the result of another dry cycle centred on 2021 and another wet cycle centred on 2032.  After then, the cycle’s amplitude diminishes as the two cycles tend to cancel each other so far as annual totals are concerned.

Chart 1

Chart 2