A tropical storm that formed off the coast of Mexico rapidly intensified Wednesday to become Hurricane Adrian, the first named storm of the hurricane season in the eastern Pacific region this year.
The storm was moving away from the mainland, westward across Pacific waters Thursday, according to the National Hurricane Center. It had maximum sustained winds of 85mph, slightly above the 74mph threshold that makes a storm a hurricane. Tropical disturbances are given a name when they encompass sustained winds of at least 39 mph
As of Thursday morning, there were no shore watches or advisories in effect for Adrian, according to the National Weather Service.
Thursday, a separate tropical storm was forecast to form further south in the Pacific, the center of hurricanes She said. As of Wednesday night, that system was more than 300 miles southeast of Acapulco, Mexico.
Maria Torres, a meteorologist at the National Hurricane Center in Miami, said Adrian will keep the same general heading through Thursday and is expected to turn west-northwest on Friday. The hurricane does not appear to pose an immediate threat to land and would remain in open waters, she said.
But Ms Torres said people living along Mexico’s coastal areas should monitor the storm and watch updates from their local weather offices, « because it can create rip currents and dangerous beach conditions. »
When a storm forms in the Atlantic or Pacific Oceans, it generally moves westward, which means that Atlantic storms usually pose a greater threat to North America. When a storm builds near land in the Pacific, it can bring damaging winds and rain before moving out to sea.
However, an air mass can sometimes block a storm, pushing it north or northeast toward the Baja California Peninsula and other parts of Mexico’s west coast. Occasionally, a storm can move further north, as was the case with last year’s post-tropical Cyclone Kay, which brought damaging winds and heavy rains to Southern California.
Some Pacific storms even travel across US land; in 1997, Hurricane Nora made landfall in Baja California before moving inland and reaching Arizona as a tropical storm.
The hurricane season in the eastern Pacific began May 15, two weeks before the start of the Atlantic season. Both seasons run until November 30th.
Complicating matters in the Pacific this year is the likely development of El Niño, the weather pattern that can have wide-ranging effects around the globe.
In the Pacific Ocean, El Niño reduces changes in wind speed and direction known as wind shear. Wind shear instability normally helps prevent storm formation, so a reduction increases the chance of storms. (In the Atlantic Ocean, El Niño has the opposite effect.)
Hawaii is located in the central Pacific but is occasionally affected by storms that form east of it. It is unusual, however, for a named storm to make landfall in Hawaii, as the land area is small and divided among several islands. The last hurricane to make landfall in Hawaii was Iniki, in 1992. In 2020, Hurricane Douglas produced damaging winds but did not directly affect the state.
On average, the Eastern Pacific hurricane season generates 15 named storms, eight of these hurricanes and four become major hurricanes with winds reaching 111 mph. The central Pacific typically sees four to five named storms develop or move through the basin each year.
There is 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 bring 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 the storms have slowed down in recent decades. When a storm slows down on water, it increases the amount of moisture the storm can absorb. As the storm slows down over land, the amount of rain falling on a single location increases. In 2019, Hurricane Dorian slowed to a crawl over the northwestern Bahamas, resulting in a total rainfall of 22.84 inches in Hope Town.
Research shows that climate change could also have other impacts on storms, including storm surges, rapid intensification and a wider reach of tropical systems.
Edward Medina, Clare Moses AND Mike Ives contributed report.