Reported and forecasted new COVID-19 cases as of November 15, 2021
Interpretation of Forecasts of New Cases
- This week’s national ensemble predicts 260,000 to 1,100,000 new cases are likely to be reported in the week ending December 11, 2021.
- Case forecasts were not assessed for likely increases or decreases because more reported cases than expected have fallen outside the forecast prediction intervals.
- Ensemble forecasts combine diverse independent team forecasts into one forecast. They have been among the most reliable forecasts in performance over time, but even the ensemble forecasts do not reliably predict rapid changes in the trends of reported cases, hospitalizations, and deaths. They should not be relied upon for making decisions about the possibility or timing of rapid changes in trends.
- The figure shows the number of new COVID-19 cases reported in the United States each week from September 11 through November 13 and forecasted new cases over the next 4 weeks, through December 11.
- This week, ensemble forecasts of new reported COVID-19 cases included forecasts from 18 modeling groups, each of which contributed a forecast for at least one jurisdiction.
- Models make various assumptions about the levels of social distancing and other interventions, which may not reflect recent changes in behavior. See model descriptions below for details on the assumptions and methods used to produce the forecasts.
State & County Forecasts
State-level and county-level forecasts show the predicted number of new COVID-19 cases for the next 4 weeks by jurisdiction. Each forecast figure uses a different scale due to differences in the number of COVID-19 cases between jurisdictions. To aid in comparisons between jurisdictions, the ensemble plot for each location has a second axis (in grey) that shows the expected number of cases per 100,000 people. Only forecasts meeting a set of ensemble inclusion criteria are shown; further details are available here: https://covid19forecasthub.org/doc/ensemble/external icon. Plots of the state-level and county-level ensemble forecasts and the underlying data can be downloaded below.
Additional forecast data and information on forecast submission are available at the COVID-19 Forecast Hubexternal icon.
Forecast Inclusion, Evaluation, and Assumptions
The teams with forecasts included in the ensembles are displayed below. Forecasts are included when they meet a set of submission and data quality requirements, further described here: https://covid19forecasthub.org/doc/ensemble/external icon.
Ensemble and individual team forecast performance is evaluated using a variety of metrics, including the assessment of prediction interval coverage, available at https://delphi.cmu.edu/forecast-eval/external icon.
The forecasts make different assumptions about social distancing measures. Additional individual model details are available here: https://github.com/cdcepi/COVID-19-Forecasts/blob/master/COVID-19_Forecast_Model_Descriptions.mdexternal icon
Intervention assumptions fall into multiple categories:
- These modeling groups make assumptions about how levels of social distancing will change in the future:
- These modeling groups assume that existing social distancing measures in each jurisdiction will continue through the projected 4-week time period:
- This modeling group makes both assumptions, combining different models:
1The full range of the prediction intervals is not visible for all state plots. Please see the forecast data for the full range of state-specific prediction intervals.