Analysis shows that a narrow but intense squall line developed as a result of a gravity wave or buoyancy wave and caused vertical shear of the horizontal winds from the surface up through cruise flight levels throughout all of the Terminal Radar Approach Control airspace. Air traffic control planning procedures are examined because the extent and severity of the weather was underestimated; consequently, air traffic managers over-delivered aircraft which lead to excessive airborne holding in regions of known turbulence.
Although not available to the operational aviation community at the time, evidence is also shown that the NOAA Earth System Research Laboratory experimental High-Resolution Rapid Refresh (HRRR) model forecasted the event. HRRR supplemental output fields could have provided the spatial and temporal resolution necessary for Managers to plan and execute an orderly reduction in air traffic demand, which, in-turn, would have improved safety and significantly reduced passenger delays. A framework for incorporating HRRR data into Air Traffic Management (ATM) Decision Support Tools and specific ATM Collaborative Decision Making guidance is offered.