Observers are concerned about two hurricanes raging off the United States’ southeastern coast and meet, creating the Fujiwhara effect. On the one hand, Hurricane Idalia is making its way toward Florida’s Gulf Coast, while Hurricane Franklin is whirling around Bermuda. It should be emphasized that these two hurricanes are brewing in close proximity, but they are not forecasted to collide. However, the news of both storms forming at the same time has raised fears about what would happen if the two storms clashed.
What is the Fujiwhara’s Effect
When two hurricanes (or cyclones, depending on your region) rotate in the same direction and approach each other, they engage in an intensive ‘rotational dance’ around a shared center, according to the National Weather Service (NWS). The Fujiwhara effect is a phenomenon that occurs when two cyclones meet. The eyes, or centers, of both storms must be within 1400 kilometers of each other for the Fujiwhara effect to occur. This occurrence was initially described in a study published in 1921 by Sakuhei Fujiwhara, a Japanese meteorologist. Many years later, when typhoons Marie and Kathy merged in 1964, the occurrence was recorded in the western Pacific Ocean.
Five Fujiwhara effect possibilities
The first hypothesis is that if one hurricane is stronger than the other, the smaller one would orbit the larger one and eventually collide with its center, resulting in absorption. Second, if two storms of about comparable strength pass close together, they may be pulled to a common center, either merging or just spinning around one another before splitting up. Third, in rare situations, if the two cyclones are powerful enough, they can combine, resulting in the formation of a supercyclone capable of wreaking havoc along coasts. Fourth, partial stretching out occurs, in which a portion of the smaller storm is lost to the environment. Fifth, complete straining occurs, in which the smaller storm is completely lost to the environment. The straining out does not occur for storms of comparable strength.
Will Idalia and Franklin cross paths?
Idalia was gathering intensity as it traveled northward on Monday (August 28), following a projected route that would take it over the Gulf of Mexico to Florida’s western coast. It produced continuous winds of 70 mph (112k/h) as it approached Cuba, but meteorologists predicted it would grow into a Category 3 hurricane before hitting Florida. Hurricane Idalia was forecast to make landfall on Wednesday (August 30) in some parts of Florida. During a press conference on Monday, Florida Governor Ron DeSantis warned of the storm’s potential devastation, asking Floridians to take the necessary safeguards. Franklin, on the other hand, was located further east, across the Atlantic Ocean. While landfall was not projected, the storm’s path was expected to continue north, parallel to the US east coast.
On Wednesday, the National Hurricane Center issued alerts for potential tropical storm conditions in Bermuda, noting the possibility of “life-threatening surf” and dangerous rip currents along the US coastline in the coming days. Idalia was predicted to reach Florida on Thursday and hug the southeastern coasts of Georgia and the Carolinas before heading into the Atlantic on Friday. Franklin’s projected path would place it above Idalia’s anticipated position on Thursday. However, there is a remote chance that the two storms will ever collide.
Why is the Fujiwhara effect so dangerous?
The Fujiwhara Effect causes cyclones to become more unpredictable due to their rapid intensification, higher rainfall, and novel patterns of movement over warming oceans. The different nature of interactions between two storm systems contributes to this complexity. The Fujiwhara Effect posed considerable difficulty for meteorologists seeking to anticipate the paths and intensity of Typhoons Parma and Melor in 2009. Because of its interaction with the stronger Typhoon Melor, the smaller Typhoon Parma unexpectedly acquired intensity, changed its direction, and lingered over the Luzon region, causing significant devastation in the Philippines. Research published in the journal Weather and Climate Extremes in September 2020 documented that the typhoon exhibited multiple U-turns and made three landfalls over Luzon.
A similar incident occurred in the Indian Ocean in April 2021, when Cyclone Seroja and Cyclone Odette collided just off the coast of Western Australia. This contact led Seroja to intensify and take unexpected turns. Seroja had already caused flooding and landslides in Indonesia before this contact. Seroja then maintained its strength and destroyed 70% of the buildings in the small Australian vacation town of Kalbarri. Furthermore, the absence of research and historical data on the Fujiwhara Effect complicates matters for weather forecasters and observers. As a result, analyzing Fujiwhara Effect events across long periods remains difficult.