Earlier in the week, a rare sub-tropical storm formed in the Southern Atlantic off the coast of Brazil. Named Arani, it never threatened land. Arani is just the third storm with tropical characteristics to develop in this region since 2004.
Today, Arani merged with another weather system and is losing its tropical characteristics. Nevertheless, as recently as yesterday, it exhibited the deep convection characteristic of tropical systems. The NASA image above illustrates cloud tops in the eastern half of the storm extending to over 40,000 feet (14 km) . The Tropical Rainfall Measuring Mission (TRMM) satellite captured the image and also sensed rainfall rates as high as two inches per hour associated with the storm.