Typhoon Namtheun Early on the morning of July 27 (Japanese local time), the Tropical Rainfall Measurement Mission (TRMM) satellite flew directly over the heart of Typhoon Namtheun. The storm, with sustained winds blowing at 105 knots (121 miles per hour), is threatening the southern islands of Japan. Compared with a TRMM overpass obtained the day before, Namtheun has undergone considerable intensification in 24 hours. The current image shows what appears to be a concentric eyewall or double eye structure, one of the hallmarks of an intense typhoon. The colors in the image indicate rainfall intensity.

The TRMM satellite, which operates the only weather radar flying in space, is a joint mission between NASA and the Japanese space agency JAXA. Images and data obtained from the TRMM satellite are used by various operational forecast centers around the world, such as the NOAA Tropical Prediction Center and the Pacific Joint Typhoon Warning Center, to obtain precise center location and intensity estimates of tropical cyclones.

June 25, 2004 2157 PR vertical Slice UTC RAINFALL	July 26, 2004 2059 UTC PR SLICE