Tropical Storm Philippe, which formed on Saturday, was meandering in the Atlantic Ocean on Monday morning and posed no immediate threat to land, forecasters said.
The National Hurricane Center estimated that the storm had sustained winds of 50 miles per hour, with higher gusts. As of 11 a.m. on Monday, it was about 1,160 miles east of the northern Leeward Islands in the Caribbean, the Hurricane Center said.
Tropical disturbances that have sustained winds of at least 39 m.p.h. are given 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.
There were no coastal warnings or watches in effect, the Hurricane Center said.
The storm’s strength was not expected to change much over the next few days as it moved west-northwest.
The Atlantic hurricane season started on June 1, and runs through Nov. 30.
In late May, the National Oceanic and Atmospheric Administration predicted that there would be 12 to 17 named storms this year, a “near-normal” amount. On Aug. 10, NOAA officials revised their estimate upward, to 14 to 21 named storms.
There were 14 named storms last year, after two extremely busy Atlantic hurricane seasons in which forecasters ran out of names and had to resort to backup lists. (A record 30 named storms took place in 2020.)
This year features an El Niño pattern, which started 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.
At the same time, this year’s higher sea surface temperatures pose a number of threats, including the ability to supercharge storms. That unusual confluence of factors has made it more difficult to predict storms.
There is 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 over the past few decades storms have slowed down, sitting over areas for longer.
When a storm slows down over water, it can absorb more moisture. When the storm slows over land, it can release more rain over a single location. 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.
Rebecca Carballo and Derrick Bryson Taylor contributed reporting.