The Atlanta Fed's running estimate of current-quarter GDP growth
A model estimate of the current quarter's US GDP growth, updated after every data release, months before the official number.
GDPNow is a nowcast: the Federal Reserve Bank of Atlanta feeds each incoming data release into a model of the GDP components and publishes the implied growth rate. Early in a quarter the estimate is driven by the model's assumptions and can move by several points as data arrive; by the end of the quarter it is usually close to the advance estimate.