Appropriately determining the tropical cyclone (TC) risk requires a high quality, homogeneous dataset of sufficient length. The specific requirements will vary according to the diverse range of applications from risk management, infrastructure design to climate change. The Bureau of Meteorology's tropical cyclone database, the best track (BT) contains parameters for location, intensity and size of variable quality and length. This poses a challenge to users to appropriately understand and interpret the BT.
The last 15 years there have been various efforts to improve the BT. New fields were added in the early 2000s including metadata and the reanalysis process has become more standardised. A comprehensive reanalysis has not been done but an abridged version has been conducted in different phases. Erroneous historical values have been modified; maximum winds have been extended back to 1973, and many events have had their intensity reassessed and modified. Nevertheless, the changing technology and their application in addition to the varying historical metadata makes it difficult to quantify the quality and homogeneity of the intensity and structure parameters.
During 2017-18, an industry funded project tasked BoM to deliver a homogenous intensity and wind radii dataset for the purpose of infrastructure design. This project enhanced the geostationary satellite archive for the application of objective techniques including the Advanced Dvorak Technique (ADT) for intensity and Digital Angle Variance (DAV) technique for wind radii and incorporated the results of other objective techniques. This delivered a dataset augmenting the BT for industry application and in so doing identified issues with the BT.
Major challenges and opportunities for the future include publishing results of BT improvements in detail, resourcing further improvements to the historical record, updating the Australian region climatology and ensuring TC events are included in the BT record as soon as possible after they occur.