Hurricane forecasters lower season projections

Probability that a major storm will hit U.S. drops from 51% to 39%.

Hurricane forecasters have lowered their projections for the 2018 season, saying they expect fewer hurricanes to form, and dropping the probability that a major hurricane will make landfall along the U.S. coastline or in the Caribbean.

The Colorado State University team said Tuesday it is predicting 11 named storms of at least tropical storm strength, with four becoming hurricanes and just one becoming a major hurricane of Category 3 or higher on the Saffir-Simpson Scale, with top sustained winds of at least 111 mph.

The team’s start-of-season forecast on May 31 had called for 14, six and two, respectively. The historical average is 12, 6½, and two. The 2017 season saw 17, 10 and 6, with Hurricanes Harvey, Irma and Maria alone creating billions in dollars of damage to the U.S., Mexico and to islands in the Caribbean.

The team also set at 39 percent the chance at least one major hurricane will strike somewhere on the U.S. coast, and a 22 percent chance of a strike somewhere on the U.S. east coast, including the Florida peninsula. The May 31 figures had been 51 percent and 30 percent, respectively.

The group never says whether a storm will strike a particular spot.

“As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them,” the report said.

“They should prepare the same for every season, regardless of how much activity is predicted.”

Philip J. Klotzbach and his team at Colorado State wrote Monday that “the tropical and subtropical Atlantic is currently much colder than normal, and the odds of a weak El Niño developing in the next several months have increased.” El Niño is the Pacific Ocean warm-water phenomenon that tends to hinder tropical storms and hurricanes.

The team said the colder waters in the Atlantic also tend to be associated with higher pressure and a more stable atmosphere, which also tend to hinder storms. And, the report said, “if El Niño were to develop, it would tend to lead to more vertical wind shear in the Caribbean extending into the tropical Atlantic, tearing apart hurricanes as they are trying to develop and intensify.”

The 2018 season started a few days early with the May 26 formation of subtropical storm Alberto, but the tropics have been relatively quiet since. The season traditionally starts heating up about Aug. 1, when storms are more likely to form far out in the Atlantic and move thousands of miles, all the while feeding on warmer water.

Colorado State’s final updated season forecast is set to come out Aug. 2.