I don't think its unbelievable, just that the prediction has a very very small probability of occurring with such a precise prediction. Widen the bounds of the prediction and the prediction becomes more probable, but with less actual usefulness in making it worthwhile to publish a warning to the public.

Saying a large earthquake will occur in the next 20 years somewhere in California is just as pointless even though the probability of making that prediction is very probable.

There has been a case made for something called 'Earthquake storms' though.

http://en.wikipedia.org/wiki/Earthquake_storm

But whether this can be applied to global scale is highly debatable.

But it might still be worthwhile looking out for domestic and wild disappearing/nervous animals i.e. The local newspaper lost pet columns have increased dramatically and poor SW reception due to increased noise, poor or strange GPS wandering/accuracy specifically due to ionospheric errors and strange cloud formations which have unusual colours.

Watching the reaction of the tourists on the beach during the boxing day tsunami is a case in point. It took a long time for the penny to drop for many of the tourists to react to the sea draining away/disappearing in front of their eyes.