The US National Oceanic and Atmospheric Administration released its annual pre-hurricane season forecast for the Atlantic Basin last week, predicting a 65 per cent chance of above-normal tropical activity this year.

NOAA, which operates the National Hurricane Center in Miami, predicted between 12 and 16 named storms; six to nine hurricanes; and two to five major hurricanes with winds of at least 111mph. An average hurricane season has 11 named storms including six hurricanes, two of which become major hurricanes.

Gerry Bell, NOAA's Climate Prediction Center's lead seasonal hurricane forecaster said the main factors influencing this year's forecast include the multi-decadal signal and the anticipated lingering effects of La Nina.

The multi-decadal signal is a cyclical combination of oceanic and atmospheric conditions that have increased hurricane activity since 1995.

"One of the expected oceanic conditions is a continuation ... of warmer-than-normal temperatures in the eastern tropical Atlantic," he said.