MORE ACTIVE HURRICANE SEASON PREDICTED

MORE ACTIVE HURRICANE SEASON PREDICTED

Less than a month after the Cayman Islands National Weather Service (CINWS) updated its 2020 hurricane season outlook on the advice of the researchers at Colorado State University’s(CSU) hurricane centre, the season seems headed for an even more ominous outlook.

Colorado State University hurricane researchers on Wednesday (August have again increased their forecast and now predict an extremely active Atlantic hurricane season in 2020, citing what they very warm sea surface temperatures and very low wind shear in the tropical Atlantic as primary factors.

The CSU Tropical Meteorology Project team is now predicting 24 named storms in 2020, including the nine named storms that have already formed (Arthur, Bertha, Cristobal, Dolly, Edouard, Fay, Gonzalo, Hanna and Isaias).

Of those, 12 are expected to become hurricanes (including the two that have already formed, Hanna and Isaias), and five to reach major hurricane strength (Saffir/Simpson category 3-4-5) with sustained winds of 111 miles per hour or greater.

Twelve hurricanes is the most the team has ever predicted in their August forecast. This is an increase from the early July seasonal forecast which predicted 20 named storms, nine hurricanes and four major hurricanes.

The team predicts that 2020 hurricane activity will be about 190 percent of the average season. By comparison, 2019’s hurricane activity was about 120 percent of the average season. The 2019 season was most notable for Hurricane Dorian which devastated the northwestern Bahamas and for Tropical Storm Imelda which caused tremendous flooding in portions of southeast Texas.

CSU says it based this forecast on a statistical model that uses approximately 40 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 (warming of waters in the central and eastern tropical Pacific), and other factors.

So far, the 2020 hurricane season is exhibiting characteristics similar to 1966, 1995, 2003, 2005, 2010 and 2017. “All of these seasons were very active in the Atlantic basin, with several (most notably 1995, 2005 and 2017) being extremely active,” said Phil Klotzbach, research scientist in the CSU Department of Atmospheric Science and lead author of the report.

The team predicts that 2020 hurricane activity will be about 190 percent of the average season. By comparison, 2019’s hurricane activity was about 120 percent of the average season. The 2019 season was most notable for Hurricane Dorian which devastated the northwestern Bahamas and for Tropical Storm Imelda which caused tremendous flooding in portions of southeast Texas.

According to CSU, tropical Atlantic sea surface temperatures averaged over the past month are at their fourth-highest levels since 1982, trailing only the very active Atlantic hurricane seasons of 2005, 2010 and 2017.

It explains that warmer-than-normal sea surface temperatures provide more fuel for tropical cyclone formation and intensification. They are also associated with a more unstable atmosphere as well as moister air, both of which favour organized thunderstorm activity that is necessary for hurricane development.

CSU also says that vertical wind shear during July was also extremely weak across the tropical Atlantic and Caribbean.

“Strong vertical wind shear tears apart hurricanes as they are trying to develop and intensify, and vertical reduced wind shear aids in hurricane development. When vertical wind shear is low in July, it also tends to be low during the peak of the Atlantic hurricane season from August-October,” the CSU experts point out.

So far, the 2020 hurricane season is exhibiting characteristics similar to 1966, 1995, 2003, 2005, 2010 and 2017. “All of these seasons were very active in the Atlantic basin, with several (most notably 1995, 2005 and 2017) being extremely active,” said Phil Klotzbach, research scientist in the CSU Department of Atmospheric Science and lead author of the report.

This is the 37th year that the CSU hurricane research team has issued an Atlantic basin seasonal hurricane forecast. CSU says its forecast is intended to provide a best estimate of activity in the Atlantic during the upcoming season – not an exact measure.