Progress towards understanding springtime fire weather extremes in Tasmania, Australia

In recent decades, there has been an increase in the occurrence of dangerous fire weather events during the Tasmanian springtime. To understand this phenomenon, a climatology of Tasmanian fire danger has been constructed,using the Mark V McArthur Forest Fire Danger meter to evaluate fire dangers from weather parameters. This climatology has established objectively the extent of changes in typical spring fire weather and has allowed comparison with any changes to fire weather in other seasons. The data have revealed little change in fire weather characteristics of other seasons, suggesting that the observed increase in springtime fire weather is not an artifact of site or instrumental changes. Individual case studies of events have been examined, identifying features of the synoptic and mesoscale situations that have led to dangerous springtime fire weather behaviour. The events studied had a number of similar aspects, including the occurrence of very dry air, but differences included the origin of the driest air in each event and local antecedent rainfall. Currently, a synoptic climatology is being assembled of weather patterns corresponding to high-end events. It is hoped that this will enable an expansion on insights gained from the case studies, and improve the predictability of dangerous springtime fire weather events.