The seasonal forecast, made every year in May before the start of the season on June 1, is meant to provide an outlook for the coming season and does not predict how many storms may make landfall.
A system was brewing in the southern Gulf on Thursday that has a 70 per cent chance of becoming a tropical cyclone, the US National Hurricane Centre (NHC) said.
The 2018 season is anticipated to be slightly more active than usual, with a 75 percent chance of an above-normal or near-normal season, NOAA representatives announced at a news conference. A TIME examination of the past 15 years of NOAA's forecasts found that the agency's predictions of the number of significant storms, which are provided as high and low estimates, are usually correct or close to correct, with some major exceptions. One to four hurricanes could be "major" with sustained winds of at least 111 miles per hour. One to four of those hurricanes could be classified as major - category three or greater on the Saffir-Simpson hurricane scale with maximum sustained winds of 111 miles per hour or greater.
NOAA forecasters will release their storm season outlook Thursday, including their predictions for how many hurricanes and tropical storms they expect to form in the Atlantic and Caribbean over the next six months.
Last year's hurricane season was one of the most active on record. NOAA is not expecting this season to be quite so bad, but an average season could do tremendous damage. One to four of the hurricanes will reportedly reach "major" hurricane status.
Over the last few years, the forecasting of a El Nino or La Nina has not been very good. As forecasters are fond of pointing out, Hurricane Andrew in 1992 struck during an otherwise inactive season.
The forecast come as scientists watch a storm in the Caribbean Sea that they said is likely to develop into a tropical system within days, and could grow into the seasons first named storm.
Last year, three exceptionally powerful hurricanes made landfall: Harvey struck Texas; Irma devastated the Caribbean and southeastern USA - creating a massive "tree graveyard" in the Everglades; and Maria walloped the Caribbean and Puerto Rico.
The names for Atlantic storms are defined by the World Meteorological Organization.
New graphics showing the "earliest reasonable" and "mostly likely" arrival times of tropical storm-force winds, to help residents prepare for storms.