The first tropical weather system of the 2016 season in the rearview mirror for the U.S. Virgin Islands and Colorado State University hurricane researchers continue to predict a near-average hurricane season for the Atlantic basin, citing several competing factors.
A tropical wave designated Invest 97L passed through the territory over the weekend and left some rain but nothing untoward. It then passed into the western Caribbean, grew in strength to become Tropical Storm Earl, and has now passed over Belize and into southern Mexico. As of Thursday afternoon there were no active systems in the Atlantic for the National Weather Service to keep an eye on.
According to meteorologists at Colorado State, upper-level winds over the tropical Atlantic have been much weaker this year than the past few years, indicating a more conducive environment for hurricane formation. However, the far North Atlantic remains quite cold, they pointed out in a news release Thursday, and this tends to create atmospheric conditions associated with increased sinking and drying motion. The atmosphere over most of the tropical Atlantic has been quite dry so far this hurricane season.
The CSU Tropical Meteorology Project team is predicting a total of 11 additional named storms to form after Aug. 1. Of those, researchers expect five to become hurricanes and two to reach major hurricane strength – Categories 3, 4 or 5 on the Saffir-Simpson scale – with sustained winds of 111 miles per hour or greater. These forecast numbers do not include Tropical Cyclones Alex, Bonnie, Colin and Danielle, which formed before Aug. 1. They do include Earl.
The team bases its forecasts on more than 60 years of historical data that include Atlantic sea surface temperatures, sea level pressures, vertical wind shear levels (the change in wind direction and speed with height in the atmosphere), El Niño conditions (warming of waters in the central and eastern tropical Pacific), and other factors.
So far, the 2016 hurricane season is exhibiting characteristics similar to 1958, 1959, 1966, 1978, 1992 and 1998, they reported.
“In general, most of these seasons experienced near to slightly above-average activity, with 1998 being a very active season,” said Phil Klotzbach, research scientist in CSU’s Department of Atmospheric Science and lead author of the report.
The team predicts that 2016 hurricane activity will be about 100 percent of the average season. By comparison, 2015’s hurricane activity was about 65 percent of the average season.
Klotzbach cautioned coastal residents to take proper precautions.
“It takes only one landfall event near you to make this an active season,” Klotzbach said.