This week marks the start of hurricane season. Forecasters predict we'll see as many as 14 named storms this year.
Now, storm trackers are concerned about a new phenomenon that could change the way we understand hurricanes.
As devastating as Hurricane Katrina was, the category five storm didn't take anyone by surprise. Forecasters saw it forming a full week before it struck the Gulf Coast in August 2005.
Classic hurricanes, like Katrina, form off the coast of Africa. But a new type of storm has forecasters worried about what may happen in the 2009 season.
"The big worry this year is not the overall tropical storms that are coming all the way from Africa," said Joe Bastardi of Accuweather.com. "They are the sudden developments in our own backyard within two to three days of hitting the coastline."
Tropical depression number one, which developed in late May is well north of the tropics and very close to the east coast, not where tropical storms are supposed to be.
Humberto in 2007 is a classic example of one of these "sudden storms." It formed off the coast of Texas, and in just one day, went from a tropical disturbance to a full-blown category one hurricane. Humberto intensified faster than any tropical storm on record, and caused $50 million in damage.
Warm water in the Atlantic and the Gulf of Mexico could be the reason these storms form.
"The caveat is in the Gulf of Mexico in August and October," said Professor Nick Shay. "You can have very strong storms form and become severe simply because warm water is there. The atmosphere is favorable and these storms can spin up to category four to five status."
And even if they're not category five strength, flooding from them is a big concern.
"You're going to get the very excessive rain and flash flooding, which over the long haul in recent time has been the number one killer of people in tropical systems," explained Bill Read of the National Hurricane Center.
And because they spin up so fast, there's little time to warn the millions of coastal residents to get out of the storm's path.
*Originally published June 5, 2009