This page contains graphs showing COVID-19 trends in cases, deaths, and testing for each state and FEMA region. The code for generating these plots can be found on my GitHub.
Severity Index: This is a crude attempt to capture both test-positivity rate and the seven-day moving average of daily new cases. It is computed by this formula: Severity = [(Cases x Positivity x 100) / (Population / 1x106)] / 100. The idea is that a low case count but a high positivity likely means far more cases than are being found. This is an attempt of sorts to figure the relative total number of cases, though the precise value shouldn't be interpreted as such. The idea is to see the relative trend in time to account for both cases and testing.