The Tropical Rainfall Measuring Mission (TRMM) satellite took this image of Typhoon Maemi organizing in the western Pacific about 900 miles east of the northern Philippines. At the time of this overpass, 18:41 UTC on 7 September 2003, Maemi was classified as a Category 1 typhoon by the Joint Typhoon Warning Center with winds estimated at 75 mph. The image gives a top down view of the storm with rainfall rates overlaid on TRMM Visible Infrared Scanner (VIRS) data (white areas). The rainfall rates were recorded by the TRMM Precipitation Radar (PR) in the inner swath and the TRMM Microwave Imager (TMI) in the outer swath.
The image shows that Maemi has a partial eyewall, a sign that the storm is not yet fully organized. Rain is falling at an intense 2 inches per hour on the eastern side of the center (semicircular dark red area), releasing heat energy into the core of the storm. TRMM images like this are providing a rare glimpse as to how the eyewall actually comes together in a developing storm.
TRMM is a joint mission between NASA and the Japanese space agency NASDA.