After a two-week period without any storms, the 2011 Atlantic hurricane season has picked up with the arrival of Hurricane Rina. Rina began as a tropical depression on October 23rd in the western Caribbean. Like many storms that form later in the season, Rina's formation was influenced by a midlatitude front that had penetrated deeper into the Tropics over warm water. These fronts can provide a focus for showers and thunderstorms that can eventually evolve into a tropical cyclone. During the peak of hurricane season in late August and September, a lot of storms form out over the central

The National Hurricane Center (NHC) upgraded an area of disturbed weather in the Caribbean to tropical depression eighteen and then to tropical storm Rina on 23 October 2011. The TRMM satellite flew over the forming tropical cyclone on 23 October 2011 at 1728 UTC (1:28 PM EDT). Data from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) showed that the future storm already was well organized and had a large area of heavy rainfall extending toward the northeast from eastern Honduras.

The TRMM satellite passed over an area of disturbed weather in the southern Caribbean Sea between Nicaragua and Jamaica on 21 October 2011 at 0929 UTC. The National Hurricane Center (NHC) has given this area a high chance (60%) of becoming a tropical cyclone over the weekend. Data from TRMM's Precipitation Radar (PR) instrument were used to make the 3-D image above that shows that a cluster of strong convective storms in the southern part of this area were higher than 15 km (~9.3 miles). The heavy rainfall in this area of deep convection releases heat, known as latent heating, into these

The accurate measurement of the tropical rainfall around the globe is one of the main objectives of the TRMM satellite. The TRMM satellite has also proven useful for global monitoring of tropical cyclone development. The images above were made from data received by the TRMM satellite when it passed over tropical cyclone 02B in the eastern Bay Of Bengal on 19 October 2011 at 2340 UTC. The image above shows a rainfall analysis that was made from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data. It shows that moderate to heavy rainfall associated with 02B was extending