Of all the things you may have anticipated to see today, the convergence of two hurricanes is certainly not one of them. Meteorologists and other climate experts attribute the strange phenomenon of today’s atmosphere to climate change, but can two hurricanes actually join together? The movies The Perfect Storm (2000) and 500 MPH (2013) have insinuated that should hurricanes collide, there will be a catastrophic result but this is far from the truth.
Is this just a wild thought?
The concept is not far-fetched, in fact, in 1921 Japanese meteorologist Sakuhei Fujiwhara posited the “Fujiwhara Effect.” It is a rare phenomenon and according to the National Weather Service:
“When two hurricanes spinning in the same direction pass close enough to each other, they begin an intense dance around their common center. If one hurricane is a lot stronger than the other, the smaller one will orbit it and eventually come crashing into its vortex to be absorbed. Two storms closer in strength can gravitate towards each other until they reach a common point and merge, or merely spin each other around for a while before shooting off on their own paths. In rare occasions, the effect is additive when the hurricanes come together, resulting in one larger storm instead of two smaller ones.”
This means that if two cyclones pass within 900 miles of each other, they can start to orbit and the size of the storm determines what happens next. If two storms get within 190 miles of each other, they can merge (Insider 2020). It may not be as fascinating as a super hurricane but at least a super hurricane will not impact the Caribbean.
Has this happened before?
The Fujiwhara Effect has occurred in the Caribbean, where Tropical Storm Iris got tangled with Hurricane Humberto around the Windward Islands in 1995. They circled each other because Iris became a hurricane and Humberto was consumed. A week later, Hurricane Iris engulfed Tropical Storm Karen which was much weaker.
The 2017 Hurricane Season was not just infamous for Hurricanes Irma and Maria, but Hurricane Hilary and soon-to-be Hurricane Irwin in the Eastern Pacific Ocean had a fatal tango of their own. The centers of both hurricanes become close, approximately 400 miles apart, which is when the Fujiwhara Effect came into play. Irwin was formed further south; after being stalled over 24 hours it was pulled up north, circled Hilary in an anticlockwise movement, and led to Hilary being weakened. They rotated around each other, merged, and then weakened in cooler water.
This year, between April 7 and 9, Tropical Storm Seroja impacted the West Australian coast, and Tropical Storm Odette positioned south, moved around Seroja. It approached the center down to a distance of below 1,400km and on April 9, the distance fell to 500km. Although this caused them both to slow down, Seroja gained more strength and subsequently engulfed Odette.
What does this mean for the future?
Luckily there is no chance that hurricanes will join forces and create one super hurricane. The Fujiwhara Effect can occur in the future, the question is when?