I started writing a post on my website about how to access raw cloud forecast data from the US GFS numerical weather model:
http://philhart.com/cloud_forecasts
Halfway through writing it, I discovered the launch of a trial alternative to the Clear Sky Clock for the rest of the world! It's called "APanel" by 7Timer:
http://7timer.y234.cn/V3/product.php...d=1&country=AS
It's what we've all been waiting for!
The raw data access I describe on my website has been quite good for the few months that I've been using it. For 2-3 nights ahead it's a great tool and better than any other combination of resources I've been using (and as much as I hate to say it, it's probably now better than most human forecasters, qualified or otherwise). It's been particularly good at forecasting high cloud which has often been a spoiler to other forecasts.
The APanel is based on the same US GFS model so the cloud forecast accuracy should be pretty good. I'm not sure how good the Seeing/Transparency forecasts will be - that will take an amateur community effort to assess!
The raw data access can provide much more detail about low/medium/high cloud, whereas the APanel lumps it all in one figure but it's much easier to use!
cheers
Phil
www.philhart.com/gallery/Astrophotography