Future changes in Extreme East Coast Lows.

Low pressure systems affecting the east coast of Australia are known as East Coast Lows (ECLs). Severe ECLs are responsible for the majority of damaging storm events in this region. How these severe ECLs may change in a future warmer climate is a major question for the area. The NSW ACT Regional Climate Modelling (NARCliM) project downscaled four global climate models with three regional climate models to produce a 12-member ensemble of high-resolution (50 km and 10 km) climate projections for southeast Australia. Using these projections, and several objective methods for identifying and tracking ECLs, future changes in severe ECLs are examined. The use of both a 12- member regional climate projection ensemble, and a range of ECL identification methods with different strengths and sensitivities, allows an assessment of robustness for these future changes in severe ECLs.

Figure 5: Ensemble composite of ECLs with wind speeds greater than 17ms-1 . Line contours indicate the sea level pressure. Coloured contours indicate the wind speed and vectors indicate the direction. The number to the top right of each panel indicates the number of events in each composite.