Tropical Storm Bret formed on Monday, becoming the second named storm of the 2023 Atlantic hurricane season.
Bret formed nearly 1,300 miles east of the Windward Islands and was moving west at 21 miles per hour to the Caribbean Sea.
The storm is expected to strengthen into a hurricane as it moves over the Lesser Antilles Thursday and Friday, the National Hurricane Center said.
The Hurricane Center estimated the storm had maximum sustained winds of 40 miles per hour. Tropical storms 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.
Bret is actually the third tropical cyclone to reach tropical storm strength this year. The National Hurricane Center announced in May which had reassessed a storm that formed off the northeastern United States in mid-January and determined it to be a subtropical storm, making it the first Atlantic cyclone of the year. However, the storm was not retroactively named, making Arlene, which formed in the Gulf of Mexico on June 2, 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, 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 this year also features El Niño, which arrived earlier this month. The phenomenon of intermittent weather can have wide-ranging effects on weather around the world, including a reduction in 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 22.84 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.