As we're approaching the anniversary of last year's devastating strike by Katrina on the Gulf Coast, we've started to receive occasional e-mails passing along photos that purport to show fascinating cloud patterns associated with the storm, or monster waves and giant storm surges rolling into the Mississippi coast.
Katrina was a powerful category 5 storm that just barely weakened to category 3 before making landfall, and did manage to produce unusually great destruction for a category 3 storm (owing to its very spread out wind field and to large waves, swells and water transport toward shore while it was a more intense approaching storm, producing surges as much as 20-28 feet above normal tide levels). There were many arresting and in some cases moving or horrifying images and videos associated with this storm. However, the e-mails that are floating around in some cases are including photos that are not related to Katrina in any way (or even to a hurricane) and others that were taken during Katrina but are inaccurately or misleadingly labeled. Fortunately, these kinds of things are usually detected and documented in various locations on the web that deal with e-mail hoaxes and assess the veracity of so-called "viral" images and video.
That said, here are some interesting links that address photos being ascribed to Katrina in some recent messages that may or may not wind up in your in-box. There are a couple of links at snopes.com regarding images of supercell thunderstorms that were actually taken in 2002 and 2004 in the Plains, and regarding a Katrina "tidal wave" or storm surge "wall of water" photo that actually depicts water overflowing an earthen levee near a power plant.