NASA's Aqua satellite found a thick ring of powerful storms around Hurricane Isaac's ragged eye and southwest of center on Sept. 10.
Infrared satellite data at 12:15 a.m. EDT (0415 UTC) on Sept. 10 from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite revealed powerful storms circling Isaac's center and in fragmented bands southwest of the center. In those areas, MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.
National - Hurricane - Center - Isaac - Cloud
The National Hurricane Center observed "Isaac's cloud pattern is currently a bit ragged-looking, with an irregular central dense overcast and limited convective banding [of thunderstorms]."