NEW YORK (NYTIMES) - Tropical Storm Sam was expected to become a "major hurricane" by this weekend after it formed in the middle of the Atlantic Ocean on Thursday (Sept 24), the fourth named storm to develop in less than a week and the 18th overall in a busy 2021 hurricane season.
As at 11pm Eastern time, the storm was about 1,600 miles (2,600km) east of the eastern Caribbean, moving west at 15mph (24kmh) with maximum sustained winds of 70mph, according to the National Hurricane Centre.
It has been a dizzying couple of months for meteorologists as the arrival of peak hurricane season - August through November - led to a run of named storms that formed in quick succession, bringing stormy weather, flooding and damaging winds to parts of the United States and the Caribbean.
Tropical Storm Odette formed Sept 17, followed days later by Peter and Rose. All three storms have since dissipated.
Tropical Storm Mindy hit the Florida Panhandle on Sept 8, just hours after it formed in the Gulf of Mexico, and as a powerful Hurricane Larry was simultaneously churning in the Atlantic.
Ida battered Louisiana as a Category 4 hurricane on Aug 29 before its remnants brought deadly flooding to the New York area. Two other tropical storms, Julian and Kate, both fizzled out within a day at the same time.
Not long before them, in the middle of last month, Tropical Storm Fred made landfall in the Florida Panhandle and Hurricane Grace hit Haiti and Mexico. Tropical Storm Henri knocked out power and brought record rainfall to the Northeastern United States on Aug 22.
The links between hurricanes and climate change are becoming more apparent. A warming planet can expect stronger hurricanes over time, and a higher incidence of the most powerful storms - though the overall number of storms could drop, because factors like stronger wind shear could keep weaker storms from forming.
Hurricanes are also becoming wetter because of more water vapour in the warmer atmosphere. Scientists have suggested storms like Hurricane Harvey in 2017 produced far more rain than they would have without the human effects on climate. Also, rising sea levels are contributing to higher storm surge - the most destructive element of tropical cyclones.
Ana became the first named storm of the season on May 23, making this the seventh year in a row that a named storm developed in the Atlantic before the official start of the season on June 1.
In May, scientists with the National Oceanic and Atmospheric Administration (NOAA) forecast that there would be 13-20 named storms this year, six to 10 of which would be hurricanes, including three to five major hurricanes of Category 3 or higher in the Atlantic.
NOAA updated its forecast early last month, predicting 15 to 21 named storms, including seven to 10 hurricanes, by the end of the season Nov 30. Sam is the 18th named storm to form this year.
Last year, there were 30 named storms, including six major hurricanes, forcing meteorologists for only a second time to exhaust the alphabet and move to using Greek letters.
It was the most named storms on record, surpassing the 28 from 2005, and the second-highest number of hurricanes.