Tropical Storm Franklin is projected to become a major hurricane on Monday, and create swells that could begin affecting Bermuda by Sunday night, the National Hurricane Center said.
As of 5 p.m. Eastern time on Sunday, Franklin was about 320 miles north-northeast of Grand Turk Island of Turks and Caicos and was moving north-northwest at eight miles per hour, the center said. Franklin’s maximum sustained winds remained at 100 miles per hour.
A major hurricane has sustained winds of 111 m.p.h. or greater, corresponding to a Category 3, 4 or 5 hurricane.
The storm is expected to cause life-threatening surf and rip currents through the beginning of this week along parts of the East Coast and then weaken in three to four days.
“Environmental conditions are fairly favorable for the next few days, with very warm sea surface temperatures and vertical wind shear forecast to decrease,” the center said.
The Hurricane Center said satellite and microwave imagery showed that Franklin had become better organized on Saturday.
Though no watches or warnings were posted, the Hurricane Center said swells generated by Franklin could start affecting Bermuda by Sunday night.
The storm left at least one person dead in the Dominican Republic and hundreds of thousands of homes without power or potable water earlier in the week.
There were 14 named storms last year, coming on the heels of two extremely busy Atlantic hurricane seasons in which forecasters ran out of names and had to resort to backup lists. (There were a record 30 named storms in 2020.)
This year features an El Niño pattern, which started in June. The intermittent climate phenomenon can have wide-ranging effects on weather around the world, and it typically impedes the number of Atlantic hurricanes.
In the Atlantic, El Niño increases the amount of wind shear, or the change in wind speed and direction from the ocean or land surface into the atmosphere. Hurricanes need a calm environment to form, and the instability caused by increased wind shear makes those conditions less likely. (El Niño has the opposite effect in the Pacific, reducing the amount of wind shear.)
At the same time, this year’s heightened sea surface temperatures pose a number of threats, including the ability to supercharge storms.
That unusual confluence of factors has made making storm predictions more difficult.
There is consensus among scientists that hurricanes are becoming more powerful because of climate change. Although there might not be more named storms overall, the likelihood of major hurricanes is increasing.
Climate change is also affecting the amount of rain that storms can produce.
In a warming world, the air can hold more moisture, which means that a named storm can hold and produce more rainfall, as Hurricane Harvey did in Texas in 2017, when some areas received more than 40 inches of rain in less than 48 hours.
Orlando Mayorquin, Rebecca Carballo, Melina Delkic, Mike Ives, Lauren McCarthy, Eduardo Medina, Christopher Mele, Claire Moses, Chris Stanford and John Yoon contributed reporting.