How likely is his prediction to come true at random, and how much more likely does he think it is now that it is a "syzygy window".

The rest of the story is what is his track record for his past predictions, and by what margin and significance did his predictions exceed chance.

Unfortunately, Jim knows little statistics, and such an analysis does not come from him.

He also doesn't realize that, in the most favorable outcome I can imagine that he has some predictive power, an announcement that the earthquake risk is 20% higher than random has no practical use.