The Machine Intelligent Gust Front Algorithm (MIGFA) was developed for the FAA by the Massachusetts Institute of Technology/Lincoln Laboratory (MIT/LL). The need to have accurate boundary detection and forecasts for FAA Terminal Air Traffic controllers, supervisors and traffic managers motivated the algorithm's development. Terminal AT users need to know where near-surface boundaries are located, where these boundaries are expected to propagate, and how significant the wind change is across the boundary.
MIGFA was originally developed to run as part of the ASR-9 Wind Shear Processor (WSP), and was then adapted to operate on data from the FAA Terminal Doppler Weather Radar (TDWR) system. The TDWR is located at major thunderstorm-impacted airports across the U.S. MIGFA shows significant improvement over the existing TDWR gust-front algorithm, and has been retrofitted in the TDWR system through the use of an outboard processor (Troxel et al. 1996).
The new FAA Integrated Terminal Weather System accesses both the TDWR data, and the narrow-band NEXRAD data. Tests were performed by MIT/LL (Mueller et al. 1997) using MIGFA on both TDWR and NEXRAD data simultaneously. They showed that while overall performance was better on TDWR primarily because of data resolution and clutter rejection, there were many cases of serious TDWR second-trip contamination in which NEXRAD was the clear winner. They concluded that a future convective storm growth algorithm run in ITWS would perform best if MIGFA (a good indicator of boundary layer forcing for convection) could be run on data from both radars. The most cost-effective solution would be to run MIGFA as part of the NEXRAD suite of algorithms.
As part of an on-going test of several severe weather detection and prediction applications for the National Weather Service, the FAA funded the integration of NEXRAD MIGFA into National Severe Storms Laboratory's (NSSL) Warning Decision Support System (WDSS). MIGFA was tested in real-time during warning operations at the Sterling, VA National Weather Service (NWS) Forecast Office during the summer of 1998.
This paper describes the MIGFA implementation within the WDSS, the resulting algorithm outputs and the feedback gathered from the Sterling NWS forecasters on the usefulness of the algorithm. The feedback from the forecasters and the performance of the algorithm will be additional metrics by which the algorithm will be considered for inclusion as an operational algorithm in the WSR-88D Radar Products Generator.
References
Mueller, et al.; Wolfson, et al.; and Eilts, et al.; 1997: The Memphis ITWS Convective Forecasting Collaborative Demonstrations. Seventh Conf. on Aviation, Range and Aerospace Meteorology, Long Beach, 249-257.
Troxel, S.W., R.L. Delanoy, J.P. Morgan, and W.L. Pughe, 1996: "Machine Intelligent Gust Front Algorithm for the Terminal Doppler Weather Radar (TDWR) and Integrated Terminal Weather System (ITWS)", Workshop on Wind Shear and Wind Shear Alert Systems, Oklahoma City, Oklahoma, Amer. Meteor. Soc., 70-79