Know your satellite images of Katrina
http://www.snopes.com/photos/katrina/satellite.asp#photo
This satellite view of a weather phenomenon has to be one of the hardest-working pictures in show business. In September 2004 it was circulated as a photograph of Hurricane Frances, in December 2004 it was circulated as a photograph of the Indian Ocean tsunami, and in August 2005 it was circulated as a photograph of Hurricane Katrina.
Despite its reputation as an all-purpose storm photograph, this picture is actually a satellite image of Hurricane Floyd from September 1999. Similar genuine satellite images of Hurricane Katrina (such as this one) can be found on the National Oceanic and Atmospheric Administration (NOAA) web site.