Tropical Storm Arlene formed in the Gulf of Mexico on Friday, making it the first named storm of the 2023 Atlantic hurricane season.
Arlene was 265 miles west of Fort Myers, Florida early Friday afternoon and was moving south towards Cuba at five miles an hour, said the National Hurricane Center in an advisory. There were no coastal controls or warnings in place, the Hurricane Center said.
The storm had sustained 40 mph winds, with higher gusts. Tropical disturbances that sustained 39 mph winds earn a name. Once winds reach 74 mph, a storm becomes a hurricane, and at 111 mph, it becomes a major hurricane.
Arlene is technically the second tropical cyclone to reach tropical storm force this year. The hurricane center announced in May which had determined a storm that formed off the northeastern United States in mid-January was a subtropical storm, making it the first Atlantic cyclone of 2023. However, the storm was not retroactively named, making Arlene the first named storm in the Atlantic Basin this year.
The Atlantic hurricane season began on June 1 and ends on November 30.
In late May, the National Oceanic and Atmospheric Administration predicted there would be 12 to 17 named storms this year, an « almost normal » amount. There were 14 named storms last year, following two extremely busy Atlantic hurricane seasons in which forecasters ran out of names and had to fall back on backup lists. (A record 30 named storms occurred in 2020.)
However, NOAA didn’t express much certainty in its predictions this year, saying there was a 40% chance of a near-normal season, a 30% chance of a better-than-normal season, and another 30% chance one season lower than normal. normal season.
There were indications of above-average ocean temperatures in the Atlantic for this season, which could fuel storms, and the potential for a higher-than-normal West African monsoon. The monsoon season produces thunderstorm activity that can lead to some of the most powerful and long-lasting Atlantic storms.
But meteorologists also expect El Niño, the intermittent climatic phenomenon that can have wide-ranging effects on weather around the world, to develop this year. This could reduce the number of Atlantic hurricanes.
« It’s a pretty rare condition for both to occur at the same time, » Matthew Rosencrans, head of hurricane forecasting at NOAA’s Climate Prediction Center, said in May.
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 to the atmosphere. Hurricanes need a calm environment to form, and the instability caused by increased wind shear makes these conditions less likely. (El Niño has the opposite effect in the Pacific, reducing the amount of wind shear.) Even in average or below-average years, there’s a chance a powerful storm will hit.
As global warming gets worse, this possibility increases. There is a solid consensus among scientists that hurricanes are getting more powerful due to climate change. While there may be no more named storms overall, the likelihood of major hurricanes is increasing.
Climate change is also affecting the amount of rain storms can produce. In a warming world, the air can hold more moisture, meaning a named storm can hold and produce more precipitation, as did Hurricane Harvey in Texas in 2017, when some areas received more than 40 inches of rain in less than 48 hours.
The researchers also found that storms have slowed down, staying over areas longer, in recent decades.
As a storm slows down on water, the amount of moisture the storm can absorb increases. As the storm slows down over land, the amount of rain falling on a single location increases. In 2019, for example, Hurricane Dorian slowed to a crawl over the northwestern Bahamas, resulting in a rainfall total of nearly 23 inches in Hope Town during the storm.
Other potential effects of climate change include increased storm surge, rapid intensification, and broader reach of tropical systems.