U.S. Could Witness Rare ‘Fujiwhara Effect’ as Two Storm Systems Target Gulf

The United States could witness a rare “Fujiwhara effect” as two storm systems are expected to come in close proximity in the Gulf of Mexico next week.

All eyes are on the gulf coast as the 2020 hurricane season nears its most active month. The National Hurricane Center (NHC) is currently tracking two storm systems. Tropical Depression Fourteen is moving northwestward over the northwestern Caribbean Sea and is expected to develop into a named storm and reach hurricane strength. Tropical Storm Laura is moving toward the U.S. from the Atlantic, prompting warnings for the Northern Leeward Islands and Puerto Rico Friday morning.

While the intensity of Laura remains uncertain, the NHC currently projects both systems to slide into the gulf, nearing landfall around the same time — Tuesday to Wednesday. This unique situation has experts on the lookout for a Fujiwhara effect, which occurs when two systems in close proximity “orbit” each other, which can result in the stronger system absorbing the weaker storm.

The National Weather Service explains:

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. But often, the effect is additive when hurricanes come together — we usually end up with one massive storm instead of two smaller ones.

According to 3WTKR, there have only been two instances where two tropical cyclones appeared in the gulf simultaneously, “in September of 1933 and June of 1959.”

The 11 a.m. advisory for both storms, per NHC: