There was 30PH that came online earlier this week... Something is coming soon...
There is no way to determine the network total hashrate either than just looking at block generation speed and those 30PH might be just variance. Why would anyone bring online 30PH to just shut it down immediately? It makes no sense.
I strongly suspect the 30TH was caused by variance and by Bitmain manufacturing, testing, and shipping S3s. Keep in mind that S3s add to the network hashrate when they are being tested, but then get turned off for a couple of days while they are being shipped all around the world.