The Atlantic hurricane season will calm this month and in November after two months of "relentless" activity, Colorado State University scientist William Gray said in a report.

Florida, which was battered by an unprecedented four hurricanes in August and September, probably won't see another major storm this year, Mr. Gray said in an updated forecast.

"This year has been a once-in-a-lifetime kind of year," Mr. Gray said. Floridians "should not expect what we have experienced this year to become the norm for future years."

This month will bring three named storms, including two hurricanes. Neither hurricane will be "major" storms, defined as having winds of at least 111 miles per hour, Mr. Gray said. November will have little tropical storm activity.

The chances of one of the three storms making landfall in the US is 33 percent, Mr. Gray said. The probability of at least one of the two hurricanes striking the US is 17 percent.

"Although we forecast an above-average 2004, there is no way we or anyone else could have foreseen the amount of Atlantic basin hurricane activity that occurred in August and September," Mr. Gray said. "We have studied more than 100 years of storm data, and this year did not behave like any other year."

Mr. Gray's research team revised its forecast for the June- through-November season. The year will have 15 named storms, including nine hurricanes, the report said. Last month, the team forecast 16 named storms and eight hurricanes.

The average season has ten tropical storms and six hurricanes, Mr. Gray said. Two of the hurricanes typically are major storms, meaning they are at least Category Three hurricanes on the five-grade Saffir-Simpson scale. Category 5 storms are the strongest.

"It is not the number of hurricanes in the Atlantic basin that has been so unusual, but rather the rare combination of high hurricane activity and very favourable surrounding hurricane steering conditions that drove so many storms from the deep tropics across Florida in such a short time," Mr. Gray said.

Last year, Mr. Gray accurately predicted that 14 named storms would develop in the Atlantic. Seven hurricanes formed, one less than forecast. He correctly predicted that three of the storms would be major hurricanes.

Tropical storms carry sustained winds of 39 mph or greater. Storms become hurricanes on the Saffir-Simpson scale when their wind speeds reach at least 74mph.

Insurers estimate that Hurricanes Charley, Frances, Ivan and Jeanne caused as much as $26 billion in damage. Jeanne, which struck Florida on September 25, may cost insurers as much as $9 billion, AIR Worldwide Corp. said.