The TRMM Precipitation Radar observed Typhoon Paka on December 10, 1997. In the middle of the storm was the eye wall, a ring of intense rainfall that is 50 km across. A tall, thin tower of rain perched on the inner edge of the eye wall.
Some scientists believe that the tower caused the rotating winds to intensify a few hours later.
In fact, the presense of the tower might have been a signal that the typhoon's destructive potential was about to increase. About 100 to 150 kilometers from the center, the outer arms of the storm circled about the eyewall. Animated GIFs are one of the few movie formats that Web browsers can display without needing special plug-in viewers.