The mean sea level pressure (MSLP) isobars show lines of equal atmospheric pressure (hPa) that have been generated from the numerical prediction model, APS2 Australian Community Climate Earth-System Simulator (ACCESS) for greater Australia. The model incorporates equations that represent the motion of the atmosphere and its associated physics. The model is run four times a day at 0UTC, 06UTC, 12UTC and 18UTC and produces hourly forecasts from 0 hours (base time) to 72 hours. The isobars are derived from a 0.11 degree grid. As there is no manual input, the products generated will differ from the official forecasts, especially in the vicinity of weather fronts, tropical cyclones or when significant late-breaking observations have become available to forecasters. The units are hPa.