If our actions are weakening the mists to any degree, we'll be able to see reality distortions on Africa, Australia, and the Oceans. We should scry and send probes to Africa and Australia - scanning first a major population center (e.g. Sydney, Lagos), and then moving on to scan for distortions.
If we can't find the source of the distortions, we could ask people in the cities if they have any news for us.
Japan's mists are extremely strong, and are able to damage or kill an observer. We'll need to send a heavily armored dropship, with a PKE meter and a reality distortion meter, to fly by Shanghai, Seoul, Fukuoka (city in Southwest Japan), Kyoto and Tokyo, sending visual, reality, and PKE readings to the Storm every step of the way. Once you lose contact, or start taking hull damage, turn right the fuck around and get the fuck out.
We'll see how close we can safely get, we land a team in whichever city we can safely reach, and ask people for more information.
That should allow us to get a much clearer idea of what's going on.
In Antarctica, we already have a probe workin' hard, we should wait to see what info it sends back to us before we take action.
We should ask the Farseers whether splitting our efforts between these places is wise, and if it's not, which we should focus on.
This should give us an initial plan for where to move to next.