This is very interesting analysis. thanks a lot Peter.
I guess the major issue for the new approach is the next 3 hours temperature forecast. For those watering at night in places where there can be large differences between day and night temperatures, it is very likely that the watering level will be not sufficient. I think the ideal calculation should take into account:
– the last 24 hours averages (temperatures, humidity) to calculate the evaporation and watering level
– adjusted with the next 3 hours rain forecast
I think this would address all concerns.