The Colorado State University (CSU) meteorological team is predicting an above-average 2013 Atlantic basin hurricane season.
The team says this due primarily to “anomalous warming” of the tropical Atlantic and expected lack of an El Nino event. CSU is in its 30th year of issuing Atlantic basin seasonal hurricane forecasts.
The team calls for 18 named storms during the hurricane season, which falls between June 1 and November 30. It said nine of those storms are expected to become hurricanes, four of which will be major hurricanes, with sustained winds of 111 miles per hour (MPH) or greater.
“The tropical Atlantic has anomalously warmed over the past several months, and it appears that the chances of an El Niño event this summer and fall are unlikely,” said Phil Klotzbach, who authored the forecast with William Gray of the CSU Tropical Meteorology Project.
“Typically, El Nino is associated with stronger vertical shear across the tropical Atlantic, creating conditions less conducive for storm formation," he added.
The team said its annual predictions are intended to provide a best estimate of activity to be experienced during the upcoming season, not an exact measure.
It said its forecasts are based on the premise that global oceanic and atmospheric conditions - such as El Nino, Atlantic basin sea and sea level pressures - that preceded active or inactive hurricane seasons in the past provide meaningful information about similar conditions that will likely occur in the current year.
“All vulnerable coastal residents should make the same hurricane preparations every year, regardless of how active or inactive the seasonal forecast is,” Klotzbach said.
“It takes only one landfall event near you to make this an active season.”
He said five hurricane seasons since 1900 exhibited oceanic and atmospheric characteristics most similar to those observed in February-March 2013: 1915, 1952, 1966, 1996 and 2004. Four out of the five years had above-average hurricane activity, he said.
The team predicts that tropical cyclone activity in 2013 will be about 175 percent of the average season.
By comparison, it said 2012 witnessed tropical cyclone activity that was 131 percent of the average season.
The hurricane forecast team's probabilities for a major hurricane making landfall in the Caribbean in 2013 is 61 percent. The average for last century is 42 percent.
The team said it will issue forecast updates on June 3 and August 2.