Instagram founders Kevin Systrom and Mike Krieger have created Rt-Covid–19, a visually rich expression of “a key measure of how fast the virus is growing”:

The metric being tracked here (Rt) represents the effective reproduction rate of the virus calculated for each locale. It lets us estimate how many secondary infections are likely to occur from a single infection in a specific area. Values over 1.0 mean we should expect more cases in that area, values under 1.0 mean we should expect fewer.

I’m not familiar with the validity of the measure, but the visualization is immediately understandable. New Jersey, my home, is on the cusp of “breaking the back of the virus,” as our governor likes to say.