Sorry to be blunt (no offence intended) but short-term (e.g. 10-20 years) weather forecasting is bollocks!
Even Bureau predictions made with relative certainty in May/June relating to the Spring "finish" often completely miss the mark.
In all honesty, there wouldn't be a reputable trading/commodity house out there that trade their book based on 3, 5, 10, 20 year forecasts. If it happens - fine! You readjust your S&D, work it into your balance sheet and trade accordingly.
