Two 'B' named storms in the Eastern Pacific this year; how could this happen?
If a tropical cyclone maintains its circulation while it treks across Central America into a different ocean basin, the system keeps its original name
Bonnie weakens after becoming first major hurricane of 2022 in Eastern Pacific
Bonnie has weakened to a Category 2 hurricane after becoming the first major hurricane of 2022 in the Eastern Pacific on Tuesday.
Hurricane Bonnie has performed what few tropical cyclones ever accomplish – maintaining the same name in two ocean basins and giving the Eastern Pacific two "B" named storms during the 2022 hurricane season.
Bonnie made landfall as a tropical storm on the Nicaraguan coast on Friday and traveled the nearly 200-mile trek across the country before emerging out over the Eastern Pacific on Saturday.
Tropical cyclone strikes on the Central American country are not rare, but a complete crossover where the center of circulation maintains its continuity is.
According to National Hurricane Center data, only around a dozen tropical cyclones have successfully crossed from the Atlantic Basin into the Eastern Pacific since the naming convention started in 1950.
Instances of a tropical cyclone maintaining its organization from the Pacific into either the Gulf of Mexico or Caribbean are even rarer, and it’s only believed to have happened a couple of times.
Tropical Storm Bonnie Satellite Animation
Tropical Storm Bonnie crossed Central America and has entered the Pacific Ocean
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Meteorologists say a combination of mountainous terrain, a tropical cyclone’s forward speed, dry air and upper-level winds usually prevent a system from keeping its identity while crossing over Central America.
With the most recent instance of Bonnie, the storm traveled over a narrow part of the region that measures less than 200 miles from the Caribbean to the Pacific.
Additionally, the core of the tropical cyclone traveled over Lake Nicaragua, the largest lake in Central America, which could have played a role in the lack of the system’s demise before reaching the Pacific.
But instead of identifying the now-Pacific storm as "Darby," it will keep its name of "Bonnie" thanks to a rule put in place by the World Meteorological Organization in 2000.
The organization’s hurricane committee says in the event of a crossover from either basin, the tropical cyclone will maintain its identification from the basin of origin.
"This is only the second time since the naming rules were changed in 2000 that this has happened – the first being Otto in 2016. Previously, all systems that reached the Pacific got new Pacific names," FOX Weather Hurricane Specialist Bryan Norcross said.
Shown above is the track of Hurricane Otto in 2016. Bonnie now joins Otto in a group of tropical cyclones that has crossed Central America and kept its original name. (National Hurricane Center)
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Both the Atlantic Basin and the Eastern Pacific have their own unique rotating lists of names meteorologists use to identify tropical cyclones.
Since Bonnie is now in the Eastern Pacific and there has already been Hurricane Blas off the coast of Mexico in early June, the 2022 season will go down in the record books for having two "B" named storms.
Hurricane seasons in both the Atlantic Basin and the Eastern Pacific run through Nov. 30.
A table showing an alphabetical list of the 2022 Eastern Pacific tropical cyclone names as selected by the World Meteorological Organization. The official Eastern Pacific hurricane season runs from May 15 through Nov. 30. (FOX Weather)