TRMM captured 2 very deep Hot Towers in the eyewall of Tropical Storm Wilma. These towers measured 15-16 km high.
On October 17, 2005 at 0302 Zulu (11:02 EDT on October 16, 2005), Wilma was classified as a Tropical Storm with sustained wind speeds of only 30 knots (34 mph) and pressure reading of 1001 mb. Forty-Eight hours later the storm had increased its intensity to category five status with sustained winds of 150 knots (172 mph). The tall towers (in red) near the center of the circulation often indicate further strengthening. Because of the size (1-20 km) and short duration (30 minute to 2 hours) of these hot towers, studies of these events have been limited to descriptive studies from aircraft observations, although a few have attempted to use the presence of hot towers in a predictive capacity. Before TRMM, no data set existed that could show globally and definitively the presence of these hot towers in cyclone systems. Aircraft radar studies of individual storms lack global coverage. Global microwave or infrared sensor observations do not provide the needed spatial resolution. With a ground resolution of 5 km, the TRMM Precipitation Radar provided the needed data set for examining the predictive value of hot towers in cyclone intensification.