Experts in the United States are considering creating a new, additional classification that counts the potential death toll of a disaster as its top priority.

The current Saffir-Simpson scale only assesses the potential for a hurricane to destroy property. Used since the early 70s, the scale divides storms into categories that estimate the likely damage from high winds and coastal "storm surge" flooding.

But when Hurricane Mitch hit Central America, it caused at least 11,000 deaths. Outbreaks of disease will push that total even higher in coming months.

Although Mitch was at the very top of the Saffir-Simpson scale when it was out at sea, its wind speeds fell as it approached land and it was downgraded.

Vulnerable area

The reason Mitch went on to kill so many people was not its wind speed but the enormous amount of water it carried - two meters of rainfall caused mudslides and flash flooding in an extremely vulnerable area.

Now the National Hurricane Centre in America wants a scale that will more accurately reflect these dangers.

It would take into account how much rain a storm is carrying, and whether it is heading for mountainous and heavily populated areas, National Hurricane Centre Director Jerry Jarrell said.

"We need a disaster scale for something that talks about casualties rather than damage [to property]."

The last Atlantic storm before Mitch to claim thousands of lives was Hurricane Fifi in 1974, blamed for 8,000 to 10,000 deaths in Honduras, also from mudslides and flash flooding.