According to
http://www.aerospace.org/cords/reentry-predictions/tiangong-1-reentry/
as of a few minutes ago the reentry window for the defunct Chinese
station has narrowed to +- 2.5 hours either side of ten after midnight
UTC tonight.
That's 2:40 pm to 7:40 pm this afternoon/evening, MST (or PDT) (UTC-7).
The general trend over the past couple of days has been for the window
to slide later, FWIW.
Looking at the ground track, the current projected middle of the window
is way out over the Pacific. Alas for free local fireworks, the overall
window comes nowhere near North America. Southern South America, much
of Africa, Central and East Asia, yes. As for you Aussies, absent a
major late change, no Skylab-Tiangong twofer. Oh well!
I notice that a bit less than one orbit after current projected
mid-window, it'll be going right over the middle of China, which could
make for a spectacular show for the people who paid for it.
Henry