CDC Updated (May 28th) COVID-19 Forecasts

#15,291

Anyone who has been caught off guard by an unpredicted storm, or monitors the shifting forecast tracks of hurricanes - which can change radically between model runs - knows that even with the power of supercomputers, forecasting is an inexact science.

As George E. P. Box (18 October 1919 – 28 March 2013) - Professor Emeritus of Statistics at the University of Wisconsin - famously said : “All models are wrong, but some models are useful.”

Pandemic models often come up in this blog, and while necessary for planning purposes, they need to be taken with a sizeable grain of salt. All are based on assumptions - and as we've seen with the modeling on COVID-19 - all are subject to change.

Six weeks ago, when there were fewer than 25,000 COVID-19 deaths in the United States, a limited number of forecast models suggested we might top out at between 60,000 and 70,000 deaths by the end of summer. 

Conditions - and assumptions - change over time, and today we are well over 100,000 COVID-19 related deaths. 

The initial forecast, made back in mid-April, was based on just five models.  This week, 15 models are used, and the CDC continues to tinker with the ensemble line-up. 

While the rate of deaths appears to be dropping, there remains much uncertainty over what will happen as more states ease social distancing restrictions and reopen their economies. The CDC's latest forecast now calls for in excess of 115,000 deaths by June 20th. 

Interpretation of Cumulative Death Forecasts

This week CDC received 15 individual national forecasts.

This week’s national ensemble forecast indicates that the rate of increase in cumulative COVID-19 deaths is continuing to decline. Nevertheless, total COVID-19 deaths are likely to exceed 115,000 by June 20.

Ensemble forecasts indicate that the rate of new deaths will vary among the states. In some states, cumulative deaths will increase at roughly the same rate as they have in recent weeks, while other states are likely to experience only a small number of additional deaths from COVID-19.

National Forecast

These forecasts show cumulative reported COVID-19 deaths since February and forecasted deaths for the next four weeks in the United States.

Models make various assumptions about the levels of social distancing and other interventions. See model descriptions below for details.

State Forecasts

State-level forecasts show observed and forecasted state-level cumulative COVID-19 deaths in the US. Each state forecast uses a different scale, due to differences in the numbers of COVID-19 deaths occurring in each state.

Forecasts fall into one of three categories

• The Auquan, CAN, ERDC, ISU, LANL and UMass-MB forecasts do not explicitly model the effects of individual social distancing measures but assume that implemented interventions will continue, resulting in decreased growth.
• The Geneva, GA_Tech, MIT, MOBS, UCLA, UA, and UT forecasts assume that existing social distancing measures will continue through the projected time period.
• The Columbia, JHU, and YYG forecasts forecasts make different assumptions about how levels of social distancing will change in the future.

Download state forecasts pdf icon[12 pages]
Download forecast data excel icon[1 sheet]

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