Forecast is an ability usable only by Castform. Forecast changes Castform's form and type in different weather. * Sunny Day - Castform changes to Fire type, Weather Ball's power is doubled, and is changed to Fire * Rain Dance - Castform changes to Water type, Weather Ball's power is doubled, and is changed to Water * Hail - Castform changes to Ice type, cannot be damaged by the Hail weather effect, Weather Ball's power is doubled, and is changed to Ice * Sandstorm - Castform doesn't change unless it is in one of the three forms above, then it will revert to its regular form. Weather Ball's power is still doubled, and is changed to Rock