En Route Weather

Prediction of significant weather impacts on operations

Weather can have significant safety and efficiency impacts on flight operations en route.  Turbulence is a major reason for injuries of crew and passengers.  Convective storms cause deviations around them that may introduce notable delays because of extra distance traveled and possibly yield in diversions if a flight cannot land at the destination due to prolonged storm impacts at that location. Moreover, lightning strokes to aircraft or hail shaft encounters in flight often lead to diversions and subsequent flight cancellations as the aircraft will have to get inspected and repaired. Airframe and engine icing can be significant safety hazards as well.

Prediction of significant weather impacts on operations are important in order to effectively manage air traffic throughout the national and international airspace. Bad forecasts can have substantial impacts on operations either through unexpected significant weather impacts (i.e., missed events) or underutilized capacity (false alarms).

The challenges are manifold and include obtaining quality weather observations, developing accurate hazard detection and prediction capabilities, understanding operationally relevant weather aspects, translation of weather into operational impacts, and effective dissemination and communication of these weather-related impacts to air traffic and airline managers, and the air crew.

RAL has considerable experience in these areas, and has fielded multiple systems that assist air traffic managers and airline staff to minimize unnecessary delays. One aspect of these systems is the incorporation of user input for display design, whether it is a standalone display in an air traffic controller tower, a desktop computer screen in an airline dispatch office, or an electronic flight bag in a cockpit. Particular users need specific formats that they are used to seeing and reacting to – and these formats are determined during the development phase of a project. Timing is important since even the most accurate information delivered too late is not effective.

Examples of RAL capabilities for En Route Weather include the Graphical Turbulence Guidance (GTG), including the radar-based NCAR Turbulence Detection Algorithm (NTDA) and the aircraft-based in-situ eddy dissipation ratio (EDR) turbulence algorithm, the Current and Forecast Icing Products (CIP and FIP), and the ALgorithm for Predicting High ice water content Areas (ALPHA), the Convective Diagnosis Oceanic (CDO) and Cloud Top Height (CTH) products, the Consolidated Storm Prediction for Aviation (CoSPA) capability, the Ensemble Prediction of Oceanic Convective Hazards (EPOCH), ceiling and visibility guidance products, or the Advanced Operational Aviation Weather System (AOAWS). As opportunities present themselves RAL will continue to develop end-to-end weather systems to aid safe and efficient en-route flight operations and air traffic management.


Matthias Steiner

Director, Aviation Applications Program