The difficult thing about “predictions with present evidence” is what “present evidence” means. For example, palm-reading and other kinds of fortune-telling are often used to practise “will”, but in fact the line on the hand or image in the crystal ball is probably seen as present evidence by the fortune teller. If you want to use this for “going to”, anything to do with fortune telling is usually popular in class. A good one that involves more vocabulary and use of a dictionary is picking five totally random words and then making a future life story out of them.
Another example where two different tenses are possible is graphs, where someone could use either “will” or “going to” to predict how markets, inflation, interest rates etc could move. If you want to use this for “going to”, you could ask students to make those predictions about next week based on graphs that you bring in, then check in the next lesson who was correct. You could also give them a selection of graphs and ask them to make predictions about how any one of them will move, e.g. “It’s almost certainly going to stay flat for at least another month or two.” Their partners can then guess which of the graphs they were talking about and say whether they agree with those predictions or not.
Perhaps the clearest use of going to for predictions is for accidents that are about to happen. This can be practised with Pictionary (drawings to represent sentences like “The apple is going to hit him on the head”) or mimes (acting out sentences like “The jar is going to fall and break”). Students could also choose one object and make “going to” predictions about that object until their partners guess what it is, e.g. “He’s going to open it”, “It’s going to blow away” and “It’s going to turn inside out” for an umbrella.
Another obvious thing to do with visual clues is to use video. The best kind is something slapstick like Mr Bean. You can pause the video just as something is about to happen and ask students to guess what is going to happen next. Alternatively, you can give them the list of “going to” sentences and ask them to shout them out when they are sure those things are going to happen within the next ten seconds. You can also extend that idea to contrast “going to for predictions” and “will for predictions”. Students must guess both the thing that they have visual evidence of (with “going to”) and the consequences (with “will”), e.g. “He’s going to punch the man, but the man won’t even notice because Mr Bean is so weak.”