Quoted By:
Forecast works like some sort protean but with weather, where it changes the weather to match the move that's about to be used, and keeping the regular effect of changing type
for example
>castform used hydro pump
>forecast ability pop up
>castform's forecast made it rain
>castform transforms
>uses hydro pump
>castform used fire blast
>forecast ability pop up
>castform's forecast made it sunny
>castform transforms
>uses fire blast
>castform used blizzard
>forecast ability pop up
>castform's forecast made it hail
>castform transforms
>uses blizzard
Flavor text would change from:
>The Pokémon transforms with the weather to change its type to Water, Fire, or Ice.
To:
>The Pokémon's Water, Fire or Ice moves change the weather accordingly, allowing it to transform with the weather to change its type.