Keep in mind, the right model is a large number of overlapping S-curves. The virus may spread like wildfire once it's entered a city, but it first has to do so.

Keep in mind, the right model is a large number of overlapping S-curves. The virus may spread like wildfire once it's entered a city, but it first has to do so. Wuhan is nearing the top of its S-curve, while other cities are still near the start. As such it would make sense for the number of cases to slow down even if it isn't actually being stopped.