What are viable return periods to investigate?

Return periods can be investigated using the Weather Generator.  However, because the weather generator is trained on a 30-year period, return periods of longer than 25 years should be investigated with caution.

In detail

Whilst the weather generator can produce 10 000 year samples it must be remembered that these series' are stationary and are validated using a much shorter observed record. When investigating return periods the user is advised to carry out uncertainty analysis using the 100 generated Weather Generator series provided.

Hourly extreme statistics are more uncertain and return periods of longer than 10 years should be investigated with caution.