The figures below show the synoptic situation in the lead up to the severe weather event. Plotted are the mean sea-level pressure as well as the positions of fronts and troughs as analysed by the Bureau of Meteorology.
Fig. P2a: MSLP chart for 0000UTC 24 Dec 2011.
Fig. P2b: Forecast MSLP chart for 0000UTC 25 Dec 2011.
Fig. P2c: Geopotential at 200 hPa for 0000UTC 24 Dec 2011.