A WEATHER phenomenon that has been recorded only once before in more than a century - a tropical storm in April - occurred close to Bermuda this week.

Tropical Storm Ana formed about 100 miles south of the island last Sunday and fortunately drifted harmlessly to the east of us.

Weather record-keeping began in 1871 and only one April subtropical or tropical storm has been recorded since then, in 1992.

Ana formed more than month before the start of the official Atlantic hurricane season, which runs from June 1 through November 30.

"Usually water temperatures are required to be a lot warmer than they are at this time for this kind of storm to form," said Bermuda Weather Service meteorologist Declan O'Connell.

"That is why the hurricane season doesn't start until June, it takes time for the sea to warm up. It is very unusual for something like this to occur so early in the year.

"But clearly, Mother Nature does not always run by the rules laid down by the National Hurricane Centre."

Last year's first tropical storm, named Arthur, formed in mid-July.

Ana was upgraded from a subtropical to a tropical storm on Tuesday, said James Franklin at the National Hurricane Centre in Miami, but by that time it was 460 miles to the east-southeast of the island and moving farther away.

Mr. Franklin did not believe the storm was a precursor to more freak weather. "It's a fluke event. I wouldn't read anything into it," he said.

By yesterday, the storm was losing power and was reclassified as an extra-tropical (non-tropical) storm as it drifted eastwards across the open ocean.

Mr. O'Connell said the weather system had begun showing tropical storm characteristics of heavy showers, thunderstorms and a tight core of strong winds (organised convection) late last Sunday.

Earlier this month one expert predicted twice as many land-falling hurricanes as usual for the 2003 season.

Colorado State University tropical storm researcher William Gray, in his 20th year of such forecasts, said he expected 12 tropical storms to form in the Atlantic basin between June and November. He predicted that eight of them would become hurricanes and three intense hurricanes with sustained winds of more than 110 miles per hour.

Last year, there were 12 named storms, four of which became hurricanes and two intense hurricanes.

"A wide variety of global indicators obtained and analysed through March continue to point to 2003 being an active Atlantic hurricane season," said Mr. Gray.

The Bermuda Weather Service will be better prepared than ever to monitor storms this season after the installation this month of new equipment which will allow meteorologists at the St. David's site to link up to a new satellite that will offer sharper quality images of gathering storms.

The equipment was donated by the US Department of Commerce which is also funding similar upgrades along the eastern seaboard.