Storage Estimates utilising rainfall parameters that are not FEH or FSR

We currently running a few simulations in Flow for projects in the Middle East and we'd benefit from a feature that allows us to do quick storage estimates using rainfall profiles applicable to those regions. Flow currently gives the attached popup stating that storage estimate are only available for FSR and FEH. Having a feature that allows for storage estimates using Middle Eastern rainfall parameters would be beneficial due to the significant work UK consultancies are doing there.