Forecasters say the rest of the hurricane season could be more active than originally projected.

Dr. William Gray of Colorado State University has revised his hurricane season forecast. The Atlantic hurricane season runs from June 1 to November 30.

Gray's numbers are up slightly to 17 tropical storms, with 9 of those expected to become hurricanes. He estimates 5 of will reach Category 3, 4, or 5 in intensity.

"The more storms that occur in the Tropical Atlantic, the greater the probability is that a major community is going to get hit," said John Baxter of the National Weather Service. "It's just the fact that there are more storms that are running around out there, the more likelihood that one's going to hit the U.S."

Gray cited abnormally low pressure and warming Atlantic Ocean temperatures for the slight increase in his forecast.