FORT COLLINS, Colo.—A noted hurricane researcher is predicting eight hurricanes will form in the Atlantic this year, and says four of them will be major.

Tuesday’s forecast by William Gray and his team of researchers at Colorado State University calls for a very active season, with 15 named storms, including tropical storm Arthur, which formed on May 31.

Gray, a former Colorado State University climatologist, pioneered the seasonal predictions in 1984. His team’s revised outlook called for the same number of hurricanes as their April forecast.

Last month, the National Oceanic and Atmospheric Administration forecast 12 to 16 named storms, including six to nine hurricanes.

Warmer water temperatures in the Atlantic and low sea level pressure contributed to the prediction of a busy season.

“Conditions in the tropical Atlantic look quite favorable for an active hurricane season,” said Phil Klotzbach, lead author of the university’s forecast.

Last June, the team predicted 17 named storms, including nine hurricanes, five of them major. The year produced 14 named storms, including six hurricanes, two of them major.