The Next Generation Air Transportation System weather requirements will bring about changes to the aviation forecast process. The key component to this requirement suite is a 4-Dimensional (4-D) Weather (Wx) Data Cube (3 spatial dimensions plus time) of weather elements available in a network enabled digital format. A subset of the 4-D Wx Data cube will include the 4-D Weather Single Authoritative Source (4-D Wx SAS). The 4-D Wx SAS is the common, consistent weather picture all National Air Space (NAS) decision makers will use throughout the system. The 4-D Wx Data Cube and the 4-D Wx SAS will include forecasts of all aviation weather parameters.

In order to meet the NextGen weather functional and performance requirements (which are still being developed), significant changes to model resolution, both temporal and spatial, are expected. If human forecasters are to add value to this type of frequently updated, high resolution model data, today's forecast techniques and methodologies must change. The National Weather Service, in conjunction with their research partners, are exploring and developing processes in which a human forecaster is “over the loop” (HOTL), adjusting model output as needed and then using the new data for various forecast products.

Two HOTL processes are currently being tested by the NWS:

• Interactive Calibration of Aviation Grids in 4 Dimensions (IC4D) – allows forecasters to adjust gridded output of fully automated aviation forecast products using a software suite compatible to existing NWS tools.

• Auto-nowcaster – NWS forecasters attempt to improve the consistency, reliability, and accuracy of 0-2 hour automated convective forecast products.

This paper will look at these potential changes to the forecast process and detail the HOTL research and development efforts in place today.