'Eye in the sky' can detect hurricanes early

A new eye in the sky is helping scientists spot infant hurricanes hiding beneath cloaks of clouds.

The satellite-based radar device, called SeaWinds, can detect the tell-tale swirl of clouds forming into a storm up to 46 hours sooner than conventional means.

Carried on the QuickSCAT satellite launched in 1999, it is designed to peer through clouds to measure winds at the ocean surface.

A team of scientists from the Atlantic Oceanographic and Meteorological Laboratory in Miami examined SeaWinds data from the regions where 12 of the named storms in the 199 hurricane season formed.

Eight of the storms eventually developed into hurricanes. The team then looked at data collected 12 to 48 hours in advance of the storms being declared tropical depressions - early hurricanes.

SeaWinds was able to provide information on eight of the 12 storms, experts at the American Association for the Advancement of Science's annual meeting in Boston, Massachusetts, were told.

In those cases, it was able to detect the closed wind circulation long before it could be seen as cloud swirls on a normal satellite image. The length of time ranged from three hours for Hurricane Irene to 46 hours for Hurricane Lenny.

Dr Timothy Liu, one of the scientists involved, said: "The ability of SeaWinds to see tropical depressions at their earliest stage gives us the opportunity to identify and study the elements that create hurricanes."

The ability to detect hurricanes early is especially important in regions such as the Gulf of Mexico where storms develop quickly and can make landfall within a few days.