Tropical Storm Earl was expected to bring two to four inches of rain over the Leeward Islands, Virgin Islands and Puerto Rico through the weekend, according to the National Hurricane Center.
The storm, which formed late on Friday, was about 75 miles north of St. Thomas, in the U.S. Virgin Islands, and moving west northwest at 8 miles per hour, forecasters said in an update early Sunday morning.
A storm is given a name after it reaches wind speeds of at least 39 m.p.h. Earl’s maximum sustained winds were near 50 m.p.h. as of 5 a.m. on Sunday.
The center of the storm was expected to pass to the north of the Virgin Islands and Puerto Rico on Sunday. The storm is expected to move to the north through Tuesday.
While no weather related warnings or watches have been issued, forecasters warned that flash flooding and gusty winds, especially in squalls, were possible over the islands throughout the weekend. Meteorologists also said that mudslides in areas of steep terrain are possible in Puerto Rico. Some areas could get up to six inches of rain.
The Atlantic hurricane season, which runs from June to November, has had a relatively quiet start, with only three named storms before this week. And there were no named storms in the Atlantic during August, the first time that has happened since 1997.
Since Thursday, two tropical storms have formed: Earl, and Tropical Storm Danielle, which briefly became the season’s first hurricane.
In early August, scientists at NOAA issued an updated forecast for the rest of the season, which still predicted an above-normal level of activity. In it, they said that the season — which runs through Nov. 30 — could see 14 to 20 named storms, with six to 10 turning into hurricanes with sustained winds of at least 74 m.p.h. Three to five of those could strengthen into what NOAA calls major hurricanes — Category 3 or stronger — with winds of at least 111 m.p.h.
Last year, there were 21 named storms, after a record-breaking 30 in 2020. For the past two years, meteorologists have exhausted the list of names used to identify storms during the Atlantic hurricane season, an occurrence that has happened only one other time, in 2005.
The links between hurricanes and climate change have become clearer with each passing year. Data shows that hurricanes have become stronger worldwide during the past four decades. Over time, a warming planet can expect stronger hurricanes 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 vapor 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.
McKenna Oxenden and Vimal Patel contributed reporting.