As one of two World Area Forecast Centres, the UK Met. Office has a responsibility to provide accurate global forecasts of significant weather for civil aviation routes. Clear Air Turbulence (CAT), a major hazard, is still relatively poorly forecast. Research is currently underway to improve the effectiveness of automated forecasts of CAT from both shear induced and mountain wave turbulence, using output from the UK Met. Office's operational forecast model.
An archive of aircraft turbulence reports maintained and held by the UKMO has been used in statistical methods to verify existing prediction algorithms and to develop new schemes. In the case of shear induced CAT, a number of different predictors, including the currently used Dutton Index, have been compared and a new predictor developed, in order to improve the skill of the 'first guess' fields available to forecasters.
The effects of mountain waves has been newly addressed, and the archive of turbulence reports has been used in a statistical method to develop and validate a new algorithm. This scheme involves the combination of gravity wave drag and wind fields produced operationally by the Unified Model, to indicate areas of high risk of mountain wave turbulence which would not otherwise be predicted.
Once validation is complete, the implementation of these two schemes will provide objective forecasts of hazardous areas due to both sources of CAT, thereby improving the safety and efficiency of civil aviation operations.
The 8th Conference on Aviation, Range, and Aerospace Meteorology