English: The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this view of a hole in a cloud formation at 3:00 p.m. local time (05:00 Universal Time) on June 5, 2012. The weather system over the Great Australian Bight cut out the oval-shaped hole from a blanket of marine stratocumulus clouds in Southern Australia at Great Australian Bight. Satellite loop at the the time the image above was taken, showed the Anticyclone was spinning anticlockwise, as it is in the Southern Hemisphere.

Sea-level pressure maps published by the Australian Bureau of Meteorology on June 5 showed that the shape of the cloud hole matched the shape of the high-pressure area. However, the center of high pressure and the cloud hole didn't match precisely; the center of the high was near the western edge of the clear area, about 100 kilometers from the cloud edge.

The area within the spot, which marks the High Pressure area, marks the boundary of 1036hpa pressure. The center of the spot was 1039hpa at the time the image was taken-more proof that this is a High Pressure area-http://earthobservatory.nasa.gov/IOTD/view.php?id=78208

The cloud hole, with a diameter that stretched as far as 1,000 kilometers (620 miles) across, was caused by sinking air associated with an area of high pressure near the surface. Globally, the average sea-level pressure is about 1013 millibars; at the center of this high, pressures topped 1,040 millibars.