How common is it for Pacific storms like Agatha to cross into the Atlantic?
The remnants of Hurricane Agatha have crossed over into the Atlantic and could turn into a tropical depression near the Gulf of Mexico and the Caribbean Sea later this week, possibly bringing heavy rain to Florida.
Is this normal? Do Pacific storms usually cross over to the Atlantic and vice-versa?
Yes, but it doesn’t happen often.
The last time the remnants of a Pacific storm turned into an Atlantic storm was in May 2020, according to The Weather Channel. Tropical Storm Amanda formed in the eastern Pacific and dissipated over the mountains of Guatemala. Its remnants restrengthened into Tropical Storm Cristobal in the Bay of Campeche in southern Mexico.
READ NEXT: Your 2022 survival guide to tropical storms, hurricanes in Miami, Broward and the Keys
Cristobal also became the first tropical storm to cross over from the Pacific into the Atlantic since 2014, when Pacific Tropical Storm Judy became Tropical Storm Hanna in the Atlantic basin, according to WUSA, a CBS-afilliated TV station in Washington, D.C. In 2013, the remnants of Pacific Hurricane Barbara turned into Tropical Storm Andrea, which then soaked South Florida. And in 2010, a Pacific tropical depression crossed into the Gulf of Mexico and grew into Tropical Storm Hermine.
Atlantic storms also sometimes cross over into the Pacific. A 2013 Sun Sentinel article said that out of 21 crossover systems that had been recorded in the past 113 years, all but six started in the Atlantic and ended up in the Pacific.
It’s difficult for storms to retain their strength as they pass through the mountainous terrain of Mexico and Central America. However, some storms have trekked through two “main pathways where it’s easier for a storm to make that crossing,” because of slightly flatter, low-lying terrain, said Jason Dunion, a meteorologist at the University of Miami and NOAA’s Hurricane Research Division.
Dunion said Agatha’s track was near a small pathway from the Gulf of Tehuantepec up into the Gulf of Mexico that is relatively flat, and while the storm “did get ripped apart by some of the terrain, it actually found that pathway.”
The other pathway is in the Caribbean to the eastern Pacific along the border of northern Costa Rica and Southern Nicaragua, where a storm can “kind of thread the needle through that high terrain,” he said.
Dunion said the last time a storm used one of these pathways to cross over into another ocean was in 2016, when Atlantic Hurricane Otto moved across Nicaragua and Costa Rica and emerged over the far eastern North Pacific as a tropical storm.
“So a lot of it comes down to the the luck of the track, as far as whether one of these storms will actually make the crossing,” Dunion said.
Do crossover storms keep their original names or get a new one?
Pacific and Atlantic tropical storms and hurricanes form the same way, although Pacific hurricanes almost never hit the U.S.
This is due to a variety of factors, including hurricanes tending to move toward the west-northwest, according to Scientific American. In the Atlantic, this puts the storm in the direction of the U.S. East Coast. In the Pacific, this tends to push the storm away from the U.S. The water in the Pacific is also colder, unlike the Atlantic’s warmer waters, making it harder for a storm to retain its strength.
But if a storm does cross over into another ocean, does it get a new name?
It depends.
If a storm moves into another ocean (EX: Atlantic to Pacific or Pacific to Atlantic), it would keep its original name if it was at least a tropical depression (which means the National Hurricane Center would still be issuing advisories) as it moved across land and into the ocean, said Dunion. However, if the storm dissipates over land and then its remnants regenerate in another ocean, officials with the National Hurricane Center would give it a new name.
“I think it’s a good reminder of just how connected Mother Nature is sometimes and we really need to be vigilant and looking in all directions as far as storms that could affect us,” he said, noting how a storm could make landfall in Mexico and its remnants could bring torrential rain to Florida or other parts of the country a few days later.
This story was originally published May 31, 2022 at 12:44 PM.
