Will the Fujiwhara Effect Influence Humberto and Imelda?

The vastness of the Atlantic Ocean makes it a rarity for two major storms to churn near each other. However, the possibility is not entirely unheard of, despite the size of this basin. Known in meteorological circles as the Fujiwhara Effect, this is what happens when two areas of low pressure come within 850 miles of each other and influence their respective behaviors. Read on for a deeper look into this weather phenomenon and how it could influence the paths of Imelda and Humberto in the days ahead.

Understanding the Delicate Dance of the Fujiwhara Effect

The Fujiwhara Effect dates back to 1921 when Japanese meteorologist Sakuhei Fujiwhara published a paper detailing his theory that two storms churning near each other could begin to rotate in unison around a common point in the middle. The precise proximity to each other that the storms need to create this effect is dependent on the size of each feature. According to the National Oceanic and Atmospheric Administration (NOAA), the Fujiwhara Effect is most likely to happen when two large storms inch within at least 850 miles of each other. This threshold shrinks to approximately 350 miles when the storms are smaller in size.

Two storms that are similar in size and strength will generally orbit around this common point before veering off in separate directions. The persistent circling of each storm pulls the other off the path that would have resulted had the interaction not occurred.