The Tropical Rainfall Measuring Mission (TRMM) satellite was placed into its low-earth orbit in November of 1997. Its primary mission has been to measure rainfall from space. TRMM has provided space borne rain radar and microwave radiometric data that measure the vertical and horizontal distribution of rainfall over the tropics. It has also been valuable for monitoring the development of tropical cyclones, especially over remote parts of the open ocean.
Tropical cyclone BUNE was southeast of the Fiji Islands and close to a category one on the Saffir-Simpson scale when the TRMM satellite passed above on 24 March 2011 at 1548 UTC. TRMM Microwave Imager (TMI) and Precipitation Radar (PR) data from this pass show that large rain bands around BUNE contained numerous intense thunderstorms.
TRMM’s TMI and PR instruments observed Cyclone Yasi as it developed from a Category 3 tropical cyclone (Feb. 1st, left), to a Category 5 event (Feb. 2nd) when it made landfall with wind gusts reported at up to 186 mph, and then finally as it began to dissipate on Feb. 3rd (right).