US researchers expect a below-average Atlantic hurricane season, estimating eight named storms between June 1 and November 30.

The Colorado State University Tropical Meteorology Project predicts tropical cyclone activity will be about 40% of average. Last year it was about 75% of average.

“The tropical Atlantic continues to exhibit conditions that are less conducive for tropical cyclone formation, and a strong El Nino event has already developed,” team member Phil Klotzbach said. 

Last year there were eight named tropical storms, the fewest since 1997.

Of the eight named storms predicted this year, Ana, Bill and Claudette have already formed.

Researchers expect two storms to become hurricanes and one to reach major hurricane strength of Category 3-5, with winds of 178kmh or more.

The university says there is a 23% probability of major hurricanes making landfall in the US. 

The team bases its forecasts on more than 60 years of historical data.

The most active part of the hurricane season is usually late August-October.