Tropical Depression 18 (TD18) formed over the southwestern
Caribbean Sea at 11 a.m. EDT on Oct. 22, and NASA's TRMM
satellite saw a "hot towering" thunderstorm near its center of
circulation hinting that it could become a tropical storm soon.
A tropical storm watch has been issued for Jamaica. When NASA's
Tropical Rainfall Measuring Mission (TRMM) satellite flew over
the developing TD18 early on Oct. 22 at 0040 UTC (Oct. 21 at
8:40 p.m. EDT), the satellite measured rainfall rates within the
low pressure area and measured cloud heights of the
thunderstorms that make up the low. TRMM noticed that the
developing depression had a "hot towering" thunderstorm over 9.3
miles (15 kilometers) high. That same area also revealed heavy
rainfall where rain was falling at 2 inches/50 mm per hour. Hot
Towers are towering clouds that emit a tremendous amount of
latent heat (that's why they're called "hot" towers). NASA
research indicates that whenever a hot tower is spotted, a
tropical cyclone will likely intensify within 6