Tropical Storm Gert formed in the Caribbean early Monday, becoming the latest named storm of the 2023 Atlantic hurricane season, before weakening over the course of the day.
Gert was one of three tropical storms, along with Emily and Franklin, that formed in the Atlantic Ocean within a span of 18 hours, signaling that the 2023 Atlantic hurricane season is far from over despite a relatively quiet summer. A fourth tropical storm, Harold, formed early Tuesday in the Gulf of Mexico.
The National Hurricane Center estimated that Gert had sustained winds of 40 miles per hour early on Monday, with higher gusts, but its sustained wind speeds had fallen to 30 m.p.h. by late Monday afternoon. Tropical disturbances that have sustained winds of 39 m.p.h. earn a name. Once winds reach 74 m.p.h., a storm becomes a hurricane, and at 111 m.p.h. it becomes a major hurricane.
Gert formed about 485 miles east of the Leeward Islands in the Caribbean and was moving west-northwest at 7 m.p.h. There were no coastal watches or warnings in effect.
In its 5 p.m. advisory, the Hurricane Center noted that Gert was “weaker” and that “it could dissipate or become post tropical at any time.”
The Atlantic hurricane season started on June 1 and runs through Nov. 30.
This year features an El Niño pattern, which arrived 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 solid storm predictions more difficult.
“Stuff just doesn’t feel right,” Philip Klotzbach, a researcher at Colorado State University who studies hurricanes, said after NOAA released its updated forecast in August. “There’s just a lot of kind of screwy things that we haven’t seen before.”
There is solid 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 a named storm can hold and produce more rainfall, like Hurricane Harvey did in Texas in 2017, when some areas received more than 40 inches of rain in less than 48 hours.
Researchers have also found that storms have slowed down, sitting over areas for longer, over the past few decades.
When a storm slows down over water, the amount of moisture the storm can absorb increases. When the storm slows over land, the amount of rain that falls over a single location increases; in 2019, for example, Hurricane Dorian slowed to a crawl over the northwestern Bahamas, resulting in a total rainfall of 22.84 inches in Hope Town during the storm.
Other potential effects of climate change include greater storm surge, rapid intensification and a broader reach of tropical systems.
Lauren McCarthy contributed reporting.