Atmospheric turbulence can be a very dynamic process. Currently, the only operational turbulence product for commercial aviation in the U.S. is the Graphical Turbulence Guidance (GTG) forecast system. This product is driven by the Rapid Update Cycle (RUC) numerical weather model output (WRF in the future), which updates on an hourly basis. On the other side of the spectrum is near real-time observational data, including PIREPs, in situ turbulence reports from commercial aircraft and in 2008 the NEXRAD Turbulence Detection Algorithm (NTDA). Another product under development is a Convectively-Induced Turbulence (CIT) diagnostic, which will combine model data, NTDA, and other observational data into a gridded data set.

Missing is an operational product that combines these disparate sources into a single, rapid-update, gridded turbulence product. Currently, the National Center for Atmospheric Research (NCAR) – under technical direction from the Federal Aviation Administration (FAA) – is developing such a product: GTGN, (“N” for nowcast). This product will combine the most current GTG grid, with the observational data and the CIT diagnostic into a seamless, gridded turbulence nowcast product. The initial concept is to produce a nowcast grid every 15 minutes. The GTG and GTGN grids will then be available for the NextGen system to provide pilots, en-route controllers, airline dispatchers, and aviation meteorologists the information they need to make tactical decisions.