Tropical depression likely to form this weekend in eastern Atlantic
FORT LAUDERDALE, Fla. -- A cluster of clouds and storms in the eastern Atlantic Ocean moving off the coast of Africa are likely to develop into a tropical depression by the weekend, the National Hurricane Center said Thursday.
The latest tropical weather outlook says the system has a high chance -- 90 percent -- of developing during the next five days.
The Atlantic tropics have been relatively quiet so far in 2018, with hurricane experts at Colorado State University saying earlier this month that weather conditions in the Atlantic have lowered the chances of a hurricane striking the U.S. this year.
Hurricanes need warm water to form, but surface temperatures in the Atlantic have been lower than average.
Another hurricane-thwarting factor has been the presence of more vertical wind shear, or the varying wind speeds in the atmosphere. Wind shear tears potential storms apart before they have a chance to form.
This latest area being monitored is so far bearing the hallmarks of the so-called Cape Verde storms that emerge in the far Atlantic at this time of year, the historic peak of the Atlantic hurricane season.
Weather experts refer to these as Cape Verde storms because these are the hurricanes that tend to form out of the north-south lines of low-pressure that radiate off Africa, often near the Cape Verde islands, an archipelago a few hundred miles off the African continent.
As these storms travel west across the Atlantic toward the Caribbean, they can become tropical cyclones if the right conditions -- warm ocean temperatures, low wind shear -- are present. The journey across the Atlantic, if the storm remains intact, can take more than a week.
In 2017, forecasters first noticed the tropical wave that would ultimately become Hurricane Irma, a Cape Verde storm, on Aug. 26. On Aug. 30, Tropical Storm Irma formed. Strengthening as it moved west across the Atlantic, Hurricane Irma came ashore in the Florida Keys on Sept. 10.