When you view a forecast, you can toggle both auto and manual predictions on and off individually.
If you want to toggle all predictions in a forecast category on or off, you can update these in bulk rather than one by one. This is a useful way to, for example, toggle off all of your auto predictions in the Sales category of your forecast.
When you view/edit a forecast, click the Controls dropdown.
Click Bulk update predictions.
You can then easily toggle all auto or manual predictions on/off for each of the corresponding forecast tabs.
When you're done, click Recalculate.