TRMM can detect various evolution stages of tropical cyclones.
Formation and Developing Stage
These images show a tropical cyclone that formed southwest of Taiwan in July 1998. Light rain is indicated in blue, broadly north and east of eye (left image). It then gathers and develops after 16 hours (right image). It has some strong parts indicated in red. After 10 hours, this cyclone grew to become Typhoon No. 1 in 1998.
This image shows typhoon PAKA that caused great damage to Guam Island in December 1997. There is no rain in the eye of this cyclone. The cloud was round, and rain existed only on the eastside of the eye. There are several strong linear rain areas, called erain bandsf around the eye and in the rain area on the east side of the eye.
This image shows cyclone PAM observed in December 1997. This cyclone had a clockwise spiral because it was located in the Southern Hemisphere. This tropical cyclone had some rain bands in the eastern rain area like a mature-stage cyclone. However, the eye and strong rain around the eye cannot be detected.