IN THE KNOW: Fujiwhara Effect

In November 2007, Typhoon “Mina” made landfall over eastern Luzon while Tropical Storm “Lando” was turning back to Philippine territory as an offshoot of the “Fujiwhara Effect,” a phenomenon which features two nearby storms rotating around each other.

The phenomenon usually starts when two weather systems come within 1,350 kilometers of each other.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration said on Friday it was looking for a “possible” Fujiwhara Effect to happen between Typhoons “Julian” and “Igme” “within the next 48 hours.”

Former Japanese meteorological bureau chief Sakuhei Fujiwhara, after whom the phenomenon is named, discovered in the 1920s that when two “water whirls” spin in the same direction near each other, they would rotate about a central point.

The larger of the two “water whirls” would dominate and eventually absorb the smaller one—thus, the Fujiwhara Effect.

The weakening of either of the two storms, their merging, or the disruption caused by another, stronger weather system usually ends the Fujiwhara Effect.

Source: Inquirer Archives