Astronomy Picture of the Day . ... Although a complete picture is still being researched, insight into this process might be gleaned by watching the above time lapse movie of the formation of Hurricane Irene , a large storm system currently threatening the eastern seaboard of the USA. Starting as a slight pressure difference visible as nondescript clouds on the lower right, Hurricane Irene is shown growing into large spiraling storm system of low pressure off the coast of South Carolina . ...